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DGN-8 DGK-8 THS4500 THS4501 D-8 www.ti.com .............................................................................................................................................................. SLOS350E – APRIL 2002– REVISED MAY 2008 WIDEBAND, LOW-DISTORTION, FULLY DIFFERENTIAL AMPLIFIERS FEATURES APPLICATIONS • • • • • • • • 1 23 • • • Fully Differential Architecture Bandwidth: 370 MHz Slew Rate: 2800 V/µs IMD3: –90 dBc at 30 MHz OIP3: 49 dBm at 30 MHz Output Common-Mode Control Wide Power-Supply Voltage Range: 5 V, ±5 V, 12 V, 15 V Input Common-Mode Range Shifted to Include Negative Power-Supply Rail Power-Down Capability (THS4500) Evaluation Module Available • • • • High Linearity Analog-to-Digital Converter Preamplifier Wireless Communication Receiver Chains Single-Ended to Differential Conversion Differential Line Driver Active Filtering of Differential Signals V −NI MV CO V+S +TV UO V +NI 1 8 2 7DP 3 6 4 5−TV UO V−S RELATED DEVICES DESCRIPTION The THS4500 and THS4501 are high-performance fully differential amplifiers from Texas Instruments. The THS4500, featuring power-down capability, and the THS4501, without power-down capability, set new performance standards for fully differential amplifiers with unsurpassed linearity, supporting 14-bit operation through 40 MHz. Package options include the SOIC-8 and the MSOP-8 with PowerPAD™ for a smaller footprint, enhanced ac performance, and improved thermal dissipation capability. DEVICE (1) (1) DESCRIPTION THS4500/1 370 MHz, 2800 V/µs, VICR Includes VS– THS4502/3 370 MHz, 2800 V/µs, Centered VICR THS4120/1 3.3 V, 100 MHz, 43 V/µs, 3.7 nV/√Hz THS4130/1 ±15 V, 150 MHz, 51 V/µs, 1.3 nV/√Hz THS4140/1 ±15 V, 160 MHz, 450 V/µs, 6.5 nV/√Hz THS4150/1 ±15 V, 150 MHz, 650 V/µs, 7.6 nV/√Hz Even-numbered devices feature power-down capability. Fp 01 MARGAC IDILTPIU PC ARIC NOIT 293 REDRO-DRIHA T LUDOMRETNI NOITROTSID Ω NOIT 26− 01 V5 05 Ω VS 473 2.65 Ω + Ω µF 9.42 − − Ω + V V5 S= 86− V S= V±5 47− NI CDA spSM 08/tiB 21 NI Vfer 9.42 Ω MV CO 1 µF V5 01 µF 08− 293 05 Ω 473 68− Ω 29− 293 Fp 01 1 2 3 204 Ω 06 04 03 0059 001 VO TU +− −+ Ω 41 008 Ω VO MC V−S 293 89− 02 01 Ω V+S Ω V 5.2 2.65 Ω VS cBd − noitrotsiD noitaludomretnI redD rOM-d I rih3T − 204 21 stiB 1.0 07 Ω 61 08 zHM − ycneuqerF −f Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. PowerPAD is a trademark of Texas Instruments, Incorporated. All other trademarks are the property of their respective owners. www.BDTIC.com/TI PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. Copyright © 2002–2008, Texas Instruments Incorporated THS4500 THS4501 SLOS350E – APRIL 2002– REVISED MAY 2008 .............................................................................................................................................................. www.ti.com This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage. ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications. ABSOLUTE MAXIMUM RATINGS (1) Over operating free-air temperature range, unless otherwise noted. UNIT Supply voltage, VS 16.5 V Input voltage, VI ±VS Output current, IO (2) 150 mA Differential input voltage, VID 4V Continuous power dissipation See Dissipation Rating Table Maximum junction temperature, TJ (3) +150°C Maximum junction temperature, continuous operation, long-term reliability, TJ +125°C Operating free-air temperature range, TA (4) C suffix 0°C to +70°C I suffix –40°C to +85°C Storage temperature range, Tstg –65°C to +150°C Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds +300°C ESD rating: (1) (2) (3) (4) HBM 4000 V CDM 1000 V MM 100 V Stresses above these ratings may cause permanent damage. Exposure to absolute maximum conditions for extended periods may degrade device reliability. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those specified is not implied. The THS4500/1 may incorporate a PowerPAD on the underside of the chip. This acts as a heat sink and must be connected to a thermally dissipative plane for proper power dissipation. Failure to do so may result in exceeding the maximum junction temperature which could permanently damage the device. See TI technical briefs SLMA002 and SLMA004 for more information about utilizing the PowerPAD thermally-enhanced package. The absolute maximum temperature under any condition is limited by the constraints of the silicon process. The maximum junction temperature for continuous operation is limited by package constraints. Operation above this temperature may result in reduced reliability and/or lifetime of the device. DISSIPATION RATINGS TABLE (1) (2) POWER RATING (2) PACKAGE θJC (°C/W) θJA (1) (°C/W) TA ≤ +25°C TA = +85°C D (8-pin) 38.3 97.5 1.02 W 410 mW DGN (8-pin) 4.7 58.4 1.71 W 685 mW DGK (8-pin) 54.2 260 385 mW 154 mW This data was taken using the JEDEC standard High-K test PCB. Power rating is determined with a junction temperature of +125°C. This is the point where distortion starts to substantially increase. Thermal management of the final PCB should strive to keep the junction temperature at or below +125°C for best performance and long-term reliability. RECOMMENDED OPERATING CONDITIONS MIN Dual supply Supply voltage Single supply Operating free- air temperature, TA 2 C suffix I suffix 4.5 NOM MAX ±5 ±7.5 5 15 0 +70 –40 +85 www.BDTIC.com/TI Submit Documentation Feedback UNIT V °C Copyright © 2002–2008, Texas Instruments Incorporated Product Folder Link(s): THS4500 THS4501 THS4500 THS4501 www.ti.com .............................................................................................................................................................. SLOS350E – APRIL 2002– REVISED MAY 2008 PACKAGE/ORDERING INFORMATION (1) ORDERABLE PACKAGE AND NUMBER TEMPERATURE 0°C to +70°C –40°C to +85°C (1) (2) PLASTIC MSOP (2) PowerPAD PLASTIC SMALL OUTLINE (D) PLASTIC MSOP (2) DGN SYMBOL DGK SYMBOL THS4500CD THS4500CDGN BFB THS4500CDGK ATVB THS4501CD THS4501CDGN BFD THS4501CDGK ATW THS4500ID THS4500IDGN BFC THS4500IDGK ASV THS4501ID THS4501IDGN BFE THS4501IDGK ASW For the most current package and ordering information see the Package Option Addendum at the end of this document, or see the TI web site at www.ti.com. All packages are available taped and reeled. The R suffix standard quantity is 2500. The T suffix standard quantity is 250 (for example, THS4501DT). PIN ASSIGNMENTS KGD ,NGD ,D 0054SHT )WEIV POT( VNI MV CO V+S +TV UO - KGD ,NGD ,D 1054SHT )WEIV POT( 1 8 V +NI 2 7DP 3 6 V S- 4 5 TVUO VNI MV CO V+S - +TV UO - 1 8 V +NI 2 7CN 3 6 V S- 4 5 TVUO www.BDTIC.com/TI Copyright © 2002–2008, Texas Instruments Incorporated Product Folder Link(s): THS4500 THS4501 - Submit Documentation Feedback 3 THS4500 THS4501 SLOS350E – APRIL 2002– REVISED MAY 2008 .............................................................................................................................................................. www.ti.com ELECTRICAL CHARACTERISTICS: VS = ±5 V RF = RG = 392 Ω, RL = 800 Ω, G = +1, and single-ended input, unless otherwise noted. THS4500 AND THS4501 PARAMETER TEST CONDITIONS TYP +25°C OVER TEMPERATURE +25°C 0°C to +70°C –40°C to +85°C UNITS MIN/ TYP/ MAX AC PERFORMANCE G = +1, PIN = –20 dBm, RF = 392 Ω 370 MHz Typ G = +2, PIN = –30 dBm, RF = 1 kΩ 175 MHz Typ G = +5, PIN = –30 dBm, RF = 2.4 kΩ 70 MHz Typ G = +10, PIN = –30 dBm, RF = 5.1 kΩ 30 MHz Typ G > +10 300 MHz Typ PIN = –20 dBm 150 MHz Typ VP = 2 V 220 MHz Typ Slew rate 4 VPP Step 2800 V/µs Typ Rise time 2 VPP Step 0.4 ns Typ Fall time 2 VPP Step 0.5 ns Typ Settling time to 0.01% VO = 4 VPP 8.3 ns Typ VO = 4 VPP 6.3 ns Typ f = 8 MHz –82 dBc Typ f = 30 MHz –71 dBc Typ Small-signal bandwidth Gain-bandwidth product Bandwidth for 0.1-dB flatness Large-signal bandwidth 0.1% Harmonic distortion G = +1, VO = 2 VPP 2nd harmonic f = 8 MHz –97 dBc Typ f = 30 MHz –74 dBc Typ VO= 2 VPP, fC= 30 MHz, RF = 392 Ω, 200 kHz tone spacing –90 dBc Typ fC = 30 MHz, RF = 392 Ω, Referenced to 50 Ω 49 dBm Typ f > 1 MHz 7 nV/√Hz Typ f > 100 kHz 1.7 pA/√Hz Typ Overdrive = 5.5 V 60 ns Typ 3rd harmonic Third-order intermodulation distortion Typ Third-order output intercept point Input voltage noise Input current noise Overdrive recovery time DC PERFORMANCE Open-loop voltage gain 55 52 50 50 dB Min Input offset voltage –4 –7/–1 –8/0 –9/+1 mV Max ±10 ±10 µV/°C Typ Max Average offset voltage drift Input bias current 4 4.6 Average bias current drift Input offset current 0.5 1 Average offset current drift 5 5.2 µA ±10 ±10 nA/°C Typ 2 2 µA Max ±40 ±40 nA/°C Typ INPUT Common-mode input range –5.7/2.6 –5.4/2.3 –5.1/2 –5.1/2 V Min Common-mode rejection ratio 80 74 70 70 dB Min Input impedance 7 Ω || pF Typ Min 10 || 1 OUTPUT Differential output voltage swing Differential output current drive Output balance error Closed-loop output impedance (single-ended) 4 RL = 1 kΩ ±8 ±7.6 ±7.4 ±7.4 V 110 100 100 RL = 20 Ω 120 mA Min PIN = –20 dBm, f = 100 kHz –58 dB Typ f = 1 MHz 0.1 Ω Typ www.BDTIC.com/TI Submit Documentation Feedback Copyright © 2002–2008, Texas Instruments Incorporated Product Folder Link(s): THS4500 THS4501 THS4500 THS4501 www.ti.com .............................................................................................................................................................. SLOS350E – APRIL 2002– REVISED MAY 2008 ELECTRICAL CHARACTERISTICS: VS = ±5 V (continued) RF = RG = 392 Ω, RL = 800 Ω, G = +1, and single-ended input, unless otherwise noted. THS4500 AND THS4501 PARAMETER TEST CONDITIONS TYP +25°C OVER TEMPERATURE 0°C to +70°C +25°C –40°C to +85°C UNITS MIN/ TYP/ MAX OUTPUT COMMON-MODE VOLTAGE CONTROL Small-signal bandwidth RL = 400 Ω 180 MHz Typ Slew rate 2 VPP Step 92 V/µs Typ Minimum gain 1 0.98 0.98 0.98 V/V Min Maximum gain 1 1.02 1.02 1.02 V/V Max –0.4 –4.6/+3.8 –6.6/+5.8 –7.6/+6.8 mV Max 100 150 170 170 µA Max ±4 ±3.7 ±3.4 ±3.4 Common-mode offset voltage Input bias current VOCM = 2.5 V Input voltage range Input impedance 25 || 1 V Min kΩ || pF Typ Maximum default voltage VOCM left floating 0 0.05 0.10 0.10 V Max Minimum default voltage VOCM left floating 0 –0.05 –0.10 –0.10 V Min Specified operating voltage ±5 7.5 7.5 7.5 V Max Maximum quiescent current 23 28 32 34 mA Max Minimum quiescent current 23 18 14 12 mA Min Power-supply rejection (±PSRR) 80 76 73 70 dB Min POWER SUPPLY POWER-DOWN (THS4500 ONLY) Enable voltage threshold Device enabled ON above –2.9 V –2.9 V Min Disable voltage threshold Device disabled OFF below –4.3 V –4.3 V Max µA Max Power-down quiescent current 800 1000 1200 1200 Input bias current 200 240 260 260 µA Max Input impedance 50 || 1 kΩ || pF Typ Turn-on time delay 1000 ns Typ Turn-off time delay 800 ns Typ www.BDTIC.com/TI Copyright © 2002–2008, Texas Instruments Incorporated Product Folder Link(s): THS4500 THS4501 Submit Documentation Feedback 5 THS4500 THS4501 SLOS350E – APRIL 2002– REVISED MAY 2008 .............................................................................................................................................................. www.ti.com ELECTRICAL CHARACTERISTICS: VS = 5 V RF = RG = 392 Ω, RL = 800 Ω, G = +1, and single-ended input, unless otherwise noted. THS4500 AND THS4501 PARAMETER TEST CONDITIONS TYP +25°C OVER TEMPERATURE +25°C 0°C to +70°C –40°C to +85°C UNITS MIN/T YP/M AX MHz Typ AC PERFORMANCE G = +1, PIN = –20 dBm, RF = 392 Ω 320 G = +2, PIN = –30 dBm, RF = 1 kΩ 160 MHz Typ G = +5, PIN = –30 dBm, RF = 2.4 kΩ 60 MHz Typ G = +10, PIN = –30 dBm, RF = 5.1 kΩ 30 MHz Typ G > +10 300 MHz Typ PIN = –20 dBm 180 MHz Typ VP = 1 V 200 MHz Typ Slew rate 2 VPP Step 1300 V/µs Typ Rise time 2 VPP Step 0.5 ns Typ Fall time 2 VPP Step 0.6 ns Typ VO = 2 V Step 13.1 ns Typ VO = 2 V Step 8.3 ns Typ f = 8 MHz, –80 dBc Typ f = 30 MHz –55 dBc Typ Small-signal bandwidth Gain-bandwidth product Bandwidth for 0.1-dB flatness Large-signal bandwidth Settling time to 0.01% 0.1% Harmonic distortion G = +1, VO = 2 VPP 2nd harmonic 3rd harmonic Input voltage noise Input current noise Overdrive recovery time Typ f = 8 MHz –76 dBc Typ f = 30 MHz –60 dBc Typ f > 1 MHz 7 nV/√Hz Typ f > 100 kHz 1.7 pA/√Hz Typ Overdrive = 5.5 V 60 ns Typ DC PERFORMANCE Open-loop voltage gain 54 51 49 49 dB Min Input offset voltage –4 –7/–1 –8/0 –9/+1 mV Max ±10 ±10 µV/°C Typ 4 4.6 5 5.2 µA Max ±10 ±10 nA/°C Typ 0.5 0.7 1.2 1.2 µA Max ±20 ±20 nA/°C Typ Average offset voltage drift Input bias current Average bias current drift Input offset current Average offset current drift INPUT Common-mode input range Common-mode rejection ratio –0.7/2.6 –0.4/2.3 –0.1/2 –0.1/2 V Min 80 74 70 70 dB Min Ω || pF Typ 107 || 1 Input Impedance OUTPUT Differential output voltage swing RL = 1 kΩ, Referenced to 2.5 V ±3.3 ±3 ±2.8 ±2.8 V Min Output current drive RL = 20 Ω 100 90 80 80 mA Min Output balance error PIN = –20 dBm, f = 100 kHz –58 dB Typ f = 1 MHz 0.1 Ω Typ Closed-loop output impedance (single-ended) 6 www.BDTIC.com/TI Submit Documentation Feedback Copyright © 2002–2008, Texas Instruments Incorporated Product Folder Link(s): THS4500 THS4501 THS4500 THS4501 www.ti.com .............................................................................................................................................................. SLOS350E – APRIL 2002– REVISED MAY 2008 ELECTRICAL CHARACTERISTICS: VS = 5 V (continued) RF = RG = 392 Ω, RL = 800 Ω, G = +1, and single-ended input, unless otherwise noted. THS4500 AND THS4501 PARAMETER TEST CONDITIONS TYP +25°C OVER TEMPERATURE +25°C 0°C to +70°C –40°C to +85°C UNITS MIN/T YP/M AX OUTPUT COMMON-MODE VOLTAGE CONTROL Small-signal bandwidth RL = 400 Ω 180 MHz Typ Slew rate 2 VPP Step 80 V/µs Typ Minimum gain 1 0.98 0.98 0.98 V/V Min Maximum gain 1 1.02 1.02 1.02 V/V Max 0.4 –2.6/3.4 –4.2/5.4 –5.6/6.4 mV Max 1 2 3 3 µA Max 1/4 1.2/3.8 1.3/3.7 1.3/3.7 Common-mode offset voltage Input bias current VOCM = 2.5 V Input voltage range Input impedance 25 || 1 V Min kΩ || pF Typ Maximum default voltage VOCM left floating 2.5 2.55 2.6 2.6 V Max Minimum default voltage VOCM left floating 2.5 2.45 2.4 2.4 V Min Specified operating voltage 5 15 15 15 V Max Maximum quiescent current 20 25 29 31 mA Max Minimum quiescent current 20 16 12 10 mA Min Power-supply rejection (+PSRR) 75 72 69 66 dB Min POWER SUPPLY POWER -DOWN (THS4500 ONLY) Enable voltage threshold Device enabled ON above 2.1 V 2.1 V Min Disable voltage threshold Device disabled OFF below 0.7 V 0.7 V Max µA Max Power-down quiescent current 600 800 1200 1200 Input bias current 100 125 140 140 µA Max Input impedance 50 || 1 kΩ || pF Typ Turn-on time delay 1000 ns Typ Turn-off time delay 800 ns Typ www.BDTIC.com/TI Copyright © 2002–2008, Texas Instruments Incorporated Product Folder Link(s): THS4500 THS4501 Submit Documentation Feedback 7 THS4500 THS4501 SLOS350E – APRIL 2002– REVISED MAY 2008 .............................................................................................................................................................. www.ti.com TYPICAL CHARACTERISTICS Table of Graphs (±5 V) FIGURE Small-signal unity-gain frequency response 1 Small-signal frequency response 2 0.1-dB gain flatness frequency response 3 Large-signal frequency response 4 Harmonic distortion (single-ended input to differential output) vs Frequency Harmonic distortion (differential input to differential output) vs Frequency 5, 7, 13, 15 6, 8, 14, 16 Harmonic distortion (single-ended input to differential output) vs Output voltage swing 9, 11, 17, 19 Harmonic distortion (differential input to differential output) vs Output voltage swing 10, 12, 18, 20 Harmonic distortion (single-ended input to differential output) vs Load resistance 21 Harmonic distortion (differential input to differential output) vs Load resistance 22 Third-order intermodulation distortion (single-ended input to differential output) vs Frequency 23 Third-order output intercept point vs Frequency 24 Slew rate vs Differential output voltage step 25 Settling time 26, 27 Large-signal transient response 28 Small-signal transient response 29 Overdrive recovery 30, 31 Voltage and current noise vs Frequency 32 Rejection ratios vs Frequency 33 Rejection ratios vs Case temperature 34 Output balance error vs Frequency 35 Open-loop gain and phase vs Frequency 36 Open-loop gain vs Case temperature 37 Input bias offset current vs Case temperature 38 Quiescent current vs Supply voltage 39 Input offset voltage vs Case temperature 40 Common-mode rejection ratio vs Input common-mode range 41 Output drive vs Case temperature 42 Harmonic distortion (single-ended and differential input to differential output) vs Output common-mode voltage 43 Small-signal frequency response at VOCM 44 Output offset voltage at VOCM vs Output common-mode voltage 45 Quiescent current vs Power-down voltage 46 Turn-on and turn-off delay times Single-ended output impedance in power-down Power-down quiescent current 8 47 vs Frequency 48 vs Case temperature 49 vs Supply voltage 50 www.BDTIC.com/TI Submit Documentation Feedback Copyright © 2002–2008, Texas Instruments Incorporated Product Folder Link(s): THS4500 THS4501 THS4500 THS4501 www.ti.com .............................................................................................................................................................. SLOS350E – APRIL 2002– REVISED MAY 2008 Table of Graphs (5 V) FIGURE Small-signal unity-gain frequency response 51 Small-signal frequency response 52 0.1-dB gain flatness frequency response 53 Large-signal frequency response 54 Harmonic distortion (single-ended input to differential output) vs Frequency 55, 57, 63, 65 Harmonic distortion (differential input to differential output) vs Frequency 56, 58, 64, 66 Harmonic distortion (single-ended input to differential output) vs Output voltage swing 59, 61, 67, 69 Harmonic distortion (differential input to differential output) vs Output voltage swing 60, 62, 68, 70 Harmonic distortion (single-ended input to differential output) vs Load resistance 71 Harmonic distortion (differential input to differential output) vs Load resistance 72 Third-order intermodulation distortion vs Frequency 73 Third-order intercept point vs Frequency 74 Slew rate vs Differential output voltage step 75 Large-signal transient response 76 Small-signal transient response 77 Voltage and current noise vs Frequency 78 Rejection ratios vs Frequency 79 Rejection ratios vs Case temperature 80 Output balance error vs Frequency 81 Open-loop gain and phase vs Frequency 82 Open-loop gain vs Case temperature 83 Input bias offset current vs Case temperature 84 Quiescent current vs Supply voltage 85 Input offset voltage vs Case temperature 86 Common-mode rejection ratio vs Input common-mode range 87 Output drive vs Case temperature 88 Harmonic distortion (single-ended and differential input) vs Output common-mode voltage 89 Output offset voltage vs Output common-mode voltage 91 Quiescent current vs Power-down voltage 92 vs Frequency 94 vs Case temperature 95 vs Supply voltage 96 Small-signal frequency response at VOCM 90 Turn-on and turn-off delay times 93 Single-ended output impedance in power-down Power-down quiescent current www.BDTIC.com/TI Copyright © 2002–2008, Texas Instruments Incorporated Product Folder Link(s): THS4500 THS4501 Submit Documentation Feedback 9 THS4500 THS4501 SLOS350E – APRIL 2002– REVISED MAY 2008 .............................................................................................................................................................. www.ti.com TYPICAL CHARACTERISTICS: ±5 V SMALL-SIGNAL UNITY-GAIN FREQUENCY RESPONSE SMALL-SIGNAL FREQUENCY RESPONSE 1 22 R ,01 = niaG 02 5.0 61 R ,5 = niaG 41 5.0− 1− Figure 1. 00R 8 L= Ω 2 mBd 03P− NI= 0 V S= V±5 2− 1.0 2.0− 3.0− 0001 Figure 2. HARMONIC DISTORTION vs FREQUENCY 0 ot tupnI dednE-elgniS 01− tuptuO laitnereffiD 02−1 = niaG 00R 8 L= Ω 03− 293 R =f Ω VV1O= 04− PP V S= V±5 05− 2− 1 = niaG 00R 8 L= Ω Ω R =f 3− 293 mBd 0P1 NI= V S= V±5 4− 001 1.0 09− 3DH 1.0 001 01 1 HARMONIC DISTORTION vs FREQUENCY 07− 3DH 09− 09− 001− 1.0 001 zHM − ycneuqerF − f 01 2DH 08− 001− 1 Figure 7. 1.0 zHM − ycneuqerF − f HARMONIC DISTORTION vs OUTPUT VOLTAGE SWING 06− 07− 08− Figure 6. 0 ot tupnI dednE-elgniS 01− tuptuO laitnereffiD 02−1 = niaG 00R 8 L= Ω 03− 293 R =f Ω zHM 8 =f 04− V S= V±5 05− 06− 2DH 1.0 zHM − ycneuqerF − f Figure 5. 0 ot tupnI laitnereffiD tuptuO 0la1i−tnereffiD 1 = niaG 02− 00R 8 L= Ω 03− 293 R =f Ω VV2O= PP 04− V S= V±5 05− 07− 3DH 001− zHM − ycneuqerF − f 06− 2DH 08− cBd − noitrotsiD cinomraH cBd − noitrotsiD cinomraH 09− 001− Figure 4. HARMONIC DISTORTION vs FREQUENCY 07− 2DH 08− 1 Figure 3. 06− 07− 01 001 01 zHM − ycneuqerF − f 0 ot tupnI laitnereffiD 01− tuptuO laitnereffiD 02−1 = niaG 00R 8 L= Ω 03− 293 R =f Ω VV1O= 04− PP V S= V±5 05− 06− 0 ot tupnI dednE-elgniS tuptuO 0la1i−tnereffiD 1 = niaG 02− 00R 8 L= Ω 03− 293 R =f Ω VV2O= PP 04− V S= V±5 05− cBd − noitrotsiD cinomraH 4 LARGE-SIGNAL FREQUENCY RESPONSE 1 09− 3DH 5 5.4 4 5.3 2DH 08− 3 5.2 2 5.1 Figure 8. 001− 1 5.0 3DH 0 V tuptVuV O −Og −niwS egatlo www.BDTIC.com/TI Submit Documentation Feedback Ω 1.0− zHM − ycneuqerF − f cBd − noitrotsiD cinomraH Bd − niaG langiS egraL 1 HARMONIC DISTORTION vs FREQUENCY 10 Ω 293 R =f Ω k 1 =f Bd − ssentalF niaG Bd 1.0 01 zHM − ycneuqerF − f 1 994 R =f 0 cBd − noitrotsiD cinomraH 001 Bd − niaG langiS llamS Bd − niaG ytinU langiS llamS 8 R ,2 = niaG 6 1− 1 1.0 01 2− 1 = niaG 5.2− 00R 8 L= Ω Ω R =f 3− 293 mBd 02P− NI= 5.3− V S= V±5 4− 1.0 0001 zHM − ycneuqerF − f 0 01 Ω k 4.2 =f 21 5.1− 1 3.0 1 = niaG 00R 8 L= Ω 2.0mBd 02P− NI= V S= V±5 Ω k 1.5 =f 81 0 01 0.1-dB GAIN FLATNESS FREQUENCY RESPONSE Figure 9. Copyright © 2002–2008, Texas Instruments Incorporated Product Folder Link(s): THS4500 THS4501 THS4500 THS4501 www.ti.com .............................................................................................................................................................. SLOS350E – APRIL 2002– REVISED MAY 2008 TYPICAL CHARACTERISTICS: ±5 V (continued) HARMONIC DISTORTION vs OUTPUT VOLTAGE SWING HARMONIC DISTORTION vs OUTPUT VOLTAGE SWING 0 Differential Input to Differential Output Gain = 1 RL = 800 Ω Rf = 499 Ω f= 8 MHz VS = ±5 V −20 −30 −40 −50 −60 −70 HD2 −80 0 Single-Ended Input to Differential Output Gain = 1 RL = 800 Ω Rf = 392 Ω f= 30 MHz VS = ±5 V −10 Harmonic Distortion − dBc −90 −20 −30 −40 −50 −60 HD2 −70 −80 HD3 −90 HD3 −100 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 0.5 1 HARMONIC DISTORTION vs FREQUENCY −60 −70 HD2 −80 3 3.5 4 4.5 −100 1 10 f − Frequency − MHz 0 −30 −40 1 1.5 2 2.5 3 3.5 4 4.5 HARMONIC DISTORTION vs FREQUENCY −20 −30 −40 −50 −60 HD2 −70 Single-Ended Input to Differential Output Gain = 2 RL = 800 Ω Rf = 1 kΩ VO = 2 VPP VS = ±5 V −10 −20 HD3 −80 −30 −40 −50 −60 HD2 −70 −80 HD3 −90 −100 1 10 f − Frequency − MHz 0.1 100 1 10 f − Frequency − MHz 100 Figure 15. HARMONIC DISTORTION vs FREQUENCY HARMONIC DISTORTION vs OUTPUT VOLTAGE SWING HARMONIC DISTORTION vs OUTPUT VOLTAGE SWING 0 Differential Input to Differential Output Gain = 2 RL = 800 Ω Rf = 1 kΩ VO = 2 VPP VS = ±5 V 0 Single-Ended Input to Differential Output Gain = 2 RL = 800 Ω Rf = 1 kΩ f= 8 MHz VS = ±5 V −10 HD2 −60 −70 −80 HD3 −20 −30 −40 −50 −60 −70 HD2 −80 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 VO − Output Voltage Swing − V Figure 16. −30 −40 −50 −60 −70 −80 HD2 HD3 −100 0 100 −20 −90 HD3 −100 1 10 f − Frequency − MHz Single-Ended Input to Differential Output Gain = 2 RL = 800 Ω Rf = 1 kΩ f= 8 MHz VS = ±5 V −10 −90 −90 5 Figure 12. Figure 14. −50 −100 0.1 0.5 Figure 13. Harmonic Distortion − dBc −20 HD3 VO − Output Voltage Swing − V Differential Input to Differential Output Gain = 2 RL = 800 Ω Rf = 1 kΩ VO = 1 VPP VS = ±5 V −100 0.1 100 0 −10 −80 5 −90 HD3 0.1 HD2 −70 0 −10 Harmonic Distortion − dBc Harmonic Distortion − dBc 2.5 Harmonic Distortion − dBc Single-Ended Input to Differential Output Gain = 2 RL = 800 Ω Rf = 1 kΩ VO = 1 VPP VS = ±5 V −50 −60 HARMONIC DISTORTION vs FREQUENCY −90 Harmonic Distortion − dBc 1.5 2 0 −40 −50 Figure 11. 0 −30 −40 VO − Output Voltage Swing − V Figure 10. −20 −30 −100 0 VO − Output Voltage Swing − V −10 −20 −90 −100 0 Differentia Input to Differential Output Gain = 1 RL = 800 Ω Rf = 392 Ω f= 30 MHz VS = ±5 V −10 Harmonic Distortion − dBc Harmonic Distortion − dBc −10 Harmonic Distortion − dBc 0 HARMONIC DISTORTION vs OUTPUT VOLTAGE SWING 0 0.5 1 1.5 2 3.5 4 4.5 5 Figure 18. www.BDTIC.com/TI Product Folder Link(s): THS4500 THS4501 3 VO − Output Voltage Swing − V Figure 17. Copyright © 2002–2008, Texas Instruments Incorporated 2.5 Submit Documentation Feedback 11 THS4500 THS4501 SLOS350E – APRIL 2002– REVISED MAY 2008 .............................................................................................................................................................. www.ti.com TYPICAL CHARACTERISTICS: ±5 V (continued) HARMONIC DISTORTION vs OUTPUT VOLTAGE SWING HARMONIC DISTORTION vs OUTPUT VOLTAGE SWING 0 Single-Ended Input to Differential Output Gain = 2 RL = 800 Ω Rf = 1 kΩ f= 30 MHz VS = ±5 V −20 −30 −40 −50 HD2 −60 0 Differentia Input to Differential Output Gain = 2 RL = 800 Ω Rf = 1 kΩ f= 8 MHz VS = ±5 V −10 −70 −80 −20 Harmonic Distortion − dBc HD3 −30 −40 −50 −60 HD2 −70 −80 −90 HD3 −40 −50 −60 1 1.5 2 2.5 3 3.5 4 4.5 5 0 0.5 1 1.5 2 −80 Third-Order Intermodulation Distortion − dBc Differential Input to Differential Output Gain = 1 VO = 2 VPP Rf = 392 Ω f= 30 MHz VS = ±5 V −40 −50 −60 HD2 −70 −80 HD3 −90 −100 0 400 800 3 3.5 4 4.5 5 −100 0 800 1200 1600 Single-Ended Input to Differential Output Gain = 1 RL = 800 Ω Rf = 392 Ω VO = 2 VPP VS = ±5 V −60 −70 −80 −90 −100 10 55 Gain = 1 RF = 392 W VO = 2 VPP VS = ± 5 V 50 45 40 35 30 0 20 f − Frequency − MHz 40 Rising Edge VO − Output Voltage − V 1500 1000 120 SETTLING TIME Rising Edge 0.6 2000 100 1.5 0.8 Gain = 1 RL = 800 Ω Rf = 392 Ω VS = ±5 V 80 Figure 24. SETTLING TIME 3000 60 f - Frequency - MHz Figure 23. SLEW RATE vs DIFFERENTIAL OUTPUT VOLTAGE STEP 1600 THIRD-ORDER OUTPUT INTERCEPT POINT vs FREQUENCY 100 Figure 22. 1200 Figure 21. −50 RL − Load Resistance − Ω 2500 400 RL − Load Resistance − Ω THIRD-ORDER INTERMODULATION DISTORTION vs FREQUENCY 0 −30 2.5 Figure 20. HARMONIC DISTORTION vs LOAD RESISTANCE −20 HD3 VO − Output Voltage Swing − V Figure 19. −10 HD2 −70 Third-Order Output Intercept Point - dBm 0.5 VO − Output Voltage Swing − V Harmonic Distortion − dBc −30 −90 −100 0 SR − Slew Rate − V/ µ s −20 −90 −100 Single-Ended Input to Differential Output Gain = 1 VO = 2 VPP Rf = 392 Ω f= 30 MHz VS = ±5 V −10 1.0 0.4 VO - Output Voltage - V Harmonic Distortion − dBc −10 Harmonic Distortion − dBc 0 HARMONIC DISTORTION vs LOAD RESISTANCE Gain = 1 RL = 800 Ω Rf = 499 Ω f= 1 MHz VS = ±5 V 0.2 0 −0.2 −0.4 Falling Edge 500 Gain = 1 RL = 800 W RF = 499 W f = 1 MHz VS = ±5 V 0.5 0 -0.5 Falling Edge -1.0 −0.6 0 12 −0.8 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 0 5 10 15 20 -1.5 0 2 4 6 8 VO − Differential Output Voltage Step − V t − Time − ns t - Time - ns Figure 25. Figure 26. Figure 27. www.BDTIC.com/TI Submit Documentation Feedback 10 12 14 Copyright © 2002–2008, Texas Instruments Incorporated Product Folder Link(s): THS4500 THS4501 THS4500 THS4501 www.ti.com .............................................................................................................................................................. SLOS350E – APRIL 2002– REVISED MAY 2008 TYPICAL CHARACTERISTICS: ±5 V (continued) SMALL-SIGNAL TRANSIENT RESPONSE 1.5 0.3 Gain = 1 RL = 800 Ω Rf = 499 Ω tr/tf = 300 ps VS = ±5 V 0.5 0 −0.5 −1 0.2 Gain = 1 RL = 800 Ω Rf = 499 Ω tr/tf = 300 ps VS = ±5 V 0.1 0 −0.1 −0.2 −0.3 −1.5 0 100 200 300 400 500 0 100 t − Time − ns 300 400 1 1 0.5 0 0 −1 −0.5 −2 −1 −3 −1.5 −4 −2 −2.5 0 500 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 t − Time − µs Figure 30. OVERDRIVE RECOVERY VOLTAGE AND CURRENT NOISE vs FREQUENCY REJECTION RATIOS vs FREQUENCY 90 0 −50 Vn 10 PSRR+ 80 70 Rejection Ratios − dB 50 Hz Source I n − Current Noise − pA/ 100 VS = ±5 V Hz Output Drive − mA 1.5 Figure 29. 60 50 CMMR PSRR− 40 30 20 In 10 RL = 800 Ω VS = ±5 V Sink 0 1 0.01 −150 −40−30−20−10 0 10 20 30 40 50 60 70 80 90 Case Temperature − °C 0.1 1 10 100 1000 −10 10 k 0.1 1 10 f − Frequency − MHz f − Frequency − kHz 100 Figure 31. Figure 32. Figure 33. REJECTION RATIOS vs CASE TEMPERATURE OUTPUT BALANCE ERROR vs FREQUENCY OPEN-LOOP GAIN AND PHASE vs FREQUENCY 0 120 Output Balance Error − dB PSRR+ 80 60 40 60 PIN = 10 dBm RL = 800 Ω Rf = 392 Ω VS = ±5 V −10 CMMR 100 Rejection Ratios − dB 2 t − Time − ns 100 20 3 2 Figure 28. 150 −100 200 Vn − Voltage Noise − nV/ 200 4 −5 −0.4 −100 RL = 800 Ω VS = ±5 V −20 −30 −40 −50 −60 −80 Case Temperature − °C 0.1 1 10 100 f − Frequency − MHz Figure 34. PIN = −30 dBm RL = 800 Ω VS = ±5 V 50 −70 0 −40−30−20−10 0 10 20 30 40 50 60 70 80 90 30 Gain Open-Loop Gain − dB −2 −100 2.5 Gain = 4 RL = 800 Ω Rf = 499 Ω Overdrive = 4.5 V VS = ±5 V 40 −30 −60 30 Phase 20 −90 10 −120 0 0.01 0.1 1 100 −150 1000 Figure 36. www.BDTIC.com/TI Product Folder Link(s): THS4500 THS4501 10 f − Frequency − MHz Figure 35. Copyright © 2002–2008, Texas Instruments Incorporated 0 Phase − ° 1 OVERDRIVE RECOVERY 5 VI − Input Voltage − V 0.4 Single-Ended Output Voltage − V 2 VO − Output Voltage − V VO − Output Voltage − V LARGE-SIGNAL TRANSIENT RESPONSE Submit Documentation Feedback 13 THS4500 THS4501 SLOS350E – APRIL 2002– REVISED MAY 2008 .............................................................................................................................................................. www.ti.com TYPICAL CHARACTERISTICS: ±5 V (continued) INPUT BIAS AND OFFSET CURRENT vs CASE TEMPERATURE 3.4 RL = 800 Ω VS = ±5 V Open-Loop Gain − dB 56 55 54 53 52 51 50 35 0 VS = ±5 V 3.3 I IB − Input Bias Current − µ A 57 IIB− −0.01 −0.02 3.2 IIB+ 3.1 QUIESCENT CURRENT vs SUPPLY VOLTAGE −0.03 3 −0.04 2.9 −0.05 2.8 −0.06 IOS 2.7 −0.07 2.6 −0.08 TA = 85°C 30 Quiescent Current − mA 58 I OS − Input Offset Current − µ A OPEN-LOOP GAIN vs CASE TEMPERATURE TA = −40°C 20 15 10 5 −0.09 2.5 −40−30−20−10 0 10 20 30 40 50 60 70 80 90 Case Temperature − °C 49 −40−30−20−10 0 10 20 30 40 50 60 70 80 90 0 Case Temperature − °C 200 110 VS = ±5 V 100 80 70 60 50 40 30 4 4.5 5 Source 100 50 0 −50 20 10 Sink −100 0 −10 −6 −5 −4 −3 −2 −1 0 Case Temperature − °C 1 2 3 4 5 6 −150 −40−30−20−10 0 10 20 30 40 50 60 70 80 90 Case Temperature − °C Input Common-Mode Voltage Range − V Figure 40. Figure 41. Figure 42. HARMONIC DISTORTION vs OUTPUT COMMON-MODE VOLTAGE SMALL-SIGNAL FREQUENCY RESPONSE AT VOCM OUTPUT OFFSET VOLTAGE AT VOCM vs OUTPUT COMMON-MODE VOLTAGE −40 HD2-SE −50 HD2 -Diff HD3-SE HD3-Diff −80 −90 −2.5 −1.5 −0.5 0.5 1.5 2.5 3.5 VOC − Output Common-Mode Voltage − V Figure 43. 600 3 Gain = 1 RL = 800 Ω Rf = 392 Ω PIN= −20 dBm VS = ±5 V 2 1 VOS − Output Offset Voltage − mV Single-Ended and Differential Input to Differential Output Gain = 1, VO = 2 VPP f= 8 MHz, Rf = 392 Ω VS = ±5 V Small Signal Frequency Response at VOCM − dB Harmonic Distortion − dBc VS = ±5 V 150 90 Output Drive − mA CMRR − Common-Mode Rejection Ratio − dB VOS − Input Offset Voltage − mV 1 0 −40 −30−20−10 0 10 20 30 40 50 60 70 80 90 14 3.5 OUTPUT DRIVE vs CASE TEMPERATURE 2 −100 −3.5 3 COMMON-MODE REJECTION RATIO vs INPUT COMMON-MODE RANGE 3 −70 2.5 INPUT OFFSET VOLTAGE vs CASE TEMPERATURE 4 −60 2 Figure 39. 5 −30 1.5 Figure 38. 6 −20 1 Figure 37. VS = ±5 V 0 0 0.5 VS − Supply Voltage − ±V 7 −10 TA = 25°C 25 0 400 200 0 −200 −1 −400 −2 −600 −3 1 10 100 1000 f − Frequency − MHz −5 −4 −3 −2 −1 Figure 44. 1 2 3 4 5 Figure 45. www.BDTIC.com/TI Submit Documentation Feedback 0 VOC − Output Common-Mode Voltage − V Copyright © 2002–2008, Texas Instruments Incorporated Product Folder Link(s): THS4500 THS4501 THS4500 THS4501 www.ti.com .............................................................................................................................................................. SLOS350E – APRIL 2002– REVISED MAY 2008 TYPICAL CHARACTERISTICS: ±5 V (continued) QUIESCENT CURRENT vs POWER-DOWN VOLTAGE TURN-ON AND TURN-OFF DELAY TIME 30 800 15 10 5 0 0.01 Current 0 0 −1 −2 −3 Quiescent Current − mA Powerdown Voltage Signal − V 20 0.02 −4 −5 −5 −5 −4.5 −4 −3.5 −3 −2.5 −2 −1.5 −1 −0.5 0 0 0.5 1 1.5 2 2.5 3 100.5 101 t − Time − ms Figure 46. 600 500 400 300 102 Gain = 1 RL = 800 Ω Rf = 392 Ω PIN = −1 dBm VS = ±5 V 200 100 0 0.1 103 1 10 100 1000 f − Frequency − MHz Figure 47. POWER-DOWN QUIESCENT CURRENT vs CASE TEMPERATURE Figure 48. POWER-DOWN QUIESCENT CURRENT vs SUPPLY VOLTAGE 1000 1000 RL = 800 Ω VS = ±5 V Power-Down Quiescent Current − µ A Power-Down Quiescent Current − µ A 700 −6 Power-Down Voltage − V 900 ZO− Single-Ended Output Impedance in Powerdown − Ω 0.03 25 Quiescent Current − mA SINGLE-ENDED OUTPUT IMPEDANCE IN POWER-DOWN vs FREQUENCY 800 700 600 500 400 300 200 100 0 −40 −30−20−10 0 10 20 30 40 50 60 70 80 90 Case Temperature − °C RL = 800 Ω 900 800 700 600 500 400 300 200 100 0 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 VS − Supply Voltage − ±V Figure 49. Figure 50. www.BDTIC.com/TI Copyright © 2002–2008, Texas Instruments Incorporated Product Folder Link(s): THS4500 THS4501 Submit Documentation Feedback 15 THS4500 THS4501 SLOS350E – APRIL 2002– REVISED MAY 2008 .............................................................................................................................................................. www.ti.com TYPICAL CHARACTERISTICS: 5 V SMALL-SIGNAL UNITY-GAIN FREQUENCY RESPONSE SMALL-SIGNAL FREQUENCY RESPONSE 1 22 R ,01 = niaG 02 0.1-dB GAIN FLATNESS FREQUENCY RESPONSE 2.0 Ω k 1.5 =f 994 R =f 0 61 R ,5 = niaG 41 1− Ω 1.0 81 k 4.2 =f Ω 0 293 R =f 21 Ω 1.0− 01 0001 zHM − ycneuqerF − f 001 01 Figure 51. 1− Figure 52. Ω Ω PP Figure 54. Ω Ω PP 06− 3DH 01 1 Figure 55. HARMONIC DISTORTION vs FREQUENCY Ω Ω PP 001 01 1 zHM − ycneuqerF − f Figure 57. 1.0 zHM − ycneuqerF − f Ω Ω 3DH 07− 2DH 08− 2DH 09− 001− 1.0 HARMONIC DISTORTION vs OUTPUT VOLTAGE SWING 06− 3DH 09− 001− Figure 56. 0 ot tupnI dednE-elgniS tuptuO0l1a−itnereffiD 02−1 = niaG 00R 8 L= 03− 293 R =f zHM 8 =f 04− V V5 S= 05− 08− 09− 3DH 1.0 zHM − ycneuqerF − f cBd − noitrotsiD cinomraH 08− 2DH 001− 07− 2DH PP 09− 06− 07− Ω Ω 08− 3DH 1.0 001 zHM − ycneuqerF − f 0 ot tupnI laitnereffiD 1i−tnereffiD tuptuO0la 02−1 = niaG 00R 8 L= 03− 994 R =f VV2O= 04− V V5 S= 05− HARMONIC DISTORTION vs FREQUENCY cBd − noitrotsiD cinomraH cBd − noitrotsiD cinomraH Bd − niaG langiS egraL 1 Figure 53. 07− 001− 01 001 01 zHM − ycneuqerF − f 06− 2DH 08− 001 V V5 S= 0 ot tupnI laitnereffiD 0 1 − tuptuO laitnereffiD 1 = niaG 02− 00R 8 L= 03− 293 R =f VV1O= 04− V V5 S= 05− 09− 0 ot tupnI dednE-elgniS 0 1 − tuptuO laitnereffiD 02−1 = niaG 00R 8 L= 03− 293 R =f VV2O= 04− V V5 S= 05− cBd − noitrotsiD cinomraH 0001 07− HARMONIC DISTORTION vs FREQUENCY 16 5.0− 06− Ω Ω Ω 00R 8 L= 4.0− mBd 02P− NI= Ω HARMONIC DISTORTION vs FREQUENCY zHM − ycneuqerF − f 1 00R 8 L= 2 mBd 03P− NI= 0 V V5 = S 2− 1.0 0 ot tupnI dednE-elgniS 01− tuptuO laitnereffiD 02−1 = niaG 00R 8 L= 03− 293 R =f VV1O= 04− V V5 S= 05− 0 1 3.0− 1 = niaG 4 LARGE-SIGNAL FREQUENCY RESPONSE 2− 1 = niaG 00R 8 L= R =f 3− 293 mBd 0P1 NI= V V5 S= 4− 1.0 2.0− Ω zHM − ycneuqerF − f 1 01 1 k 1 =f Bd − ssentalF niaG Bd 1.0 Ω Ω Bd − niaG langiS llamS 8 R ,2 = niaG 6 cBd − noitrotsiD cinomraH 1 Bd − niaG ytinU langiS llamS 01 2− 1 = niaG 00R 8 L= R =f 3− 293 mBd 02P− NI= V V5 S= 4− 1.0 3 5.2 001− 5.1 2 Figure 58. 1 0 5.0 V tuptVuV O −Og −niwS egatlo www.BDTIC.com/TI Submit Documentation Feedback Figure 59. Copyright © 2002–2008, Texas Instruments Incorporated Product Folder Link(s): THS4500 THS4501 THS4500 THS4501 www.ti.com .............................................................................................................................................................. SLOS350E – APRIL 2002– REVISED MAY 2008 TYPICAL CHARACTERISTICS: 5 V (continued) HARMONIC DISTORTION vs OUTPUT VOLTAGE SWING HARMONIC DISTORTION vs OUTPUT VOLTAGE SWING 0 Differentia Input to Differential Output Gain = 1 RL = 800 Ω Rf = 392 Ω f= 8 MHz VS = 5 V −20 −30 −40 −50 −60 HD3 −70 −80 HD2 −90 −100 0 0.5 1 0 Single-Ended Input to Differential Output Gain = 1 RL = 800 Ω Rf = 392 Ω f = 30 MHz VS = 5 V −10 Harmonic Distortion − dBc 1.5 2 2.5 −20 −30 −40 HD2 −60 −70 −80 −30 −40 −70 −80 −90 −100 0.5 1 1.5 2 2.5 3 0 HARMONIC DISTORTION vs FREQUENCY −70 HD2 −80 −90 HARMONIC DISTORTION vs FREQUENCY Differential Input to Differential Output Gain = 2 RL = 800 Ω Rf = 1 kΩ VO = 1 VPP VS = 5 V −20 −30 −40 −50 HD2 −60 −70 −80 1 10 −20 −30 −40 −50 −60 −80 1 10 f − Frequency − MHz −50 1 10 f − Frequency − MHz 100 Figure 65. HARMONIC DISTORTION vs FREQUENCY HARMONIC DISTORTION vs OUTPUT VOLTAGE SWING HARMONIC DISTORTION vs OUTPUT VOLTAGE SWING 0 Differential Input to Differential Output Gain = 2 RL = 800 Ω Rf = 1 kΩ VO = 2 VPP VS = 5 V HD3 −70 0 Single-Ended Input to Differential Output Gain = 2 RL = 800 Ω Rf = 1 kΩ f = 8 MHz VS = 5 V −10 −60 HD2 −80 −90 −100 0.1 −100 0.1 Figure 64. Harmonic Distortion − dBc −40 100 Figure 63. 0 −30 HD2 −90 f − Frequency − MHz −20 HD3 −70 HD3 −100 0.1 100 Single-Ended Input to Differential Output Gain = 2 RL = 800 Ω Rf = 1 kΩ VO = 2 VPP VS = 5 V −10 −90 −100 3 0 −10 HD3 −60 −10 2.5 Figure 62. −50 0.1 2 Figure 61. Harmonic Distortion − dBc −40 1.5 Figure 60. Harmonic Distortion − dBc −30 1 VO − Output Voltage Swing − V Single-Ended Input to Differential Output Gain = 2 RL = 800 Ω Rf = 1 kΩ VO = 1 VPP VS = 5 V −20 0.5 VO − Output Voltage Swing − V 0 −10 HD2 −60 −100 0 HD3 −50 −90 HARMONIC DISTORTION vs FREQUENCY Harmonic Distortion − dBc −20 VO − Output Voltage Swing − V 0 Harmonic Distortion − dBc HD3 −50 3 Differentia Input to Differential Output Gain = 1 RL = 800 Ω Rf = 392 Ω f= 30 MHz VS = 5 V −10 −20 −30 −40 −50 −60 HD3 −70 −80 HD2 −90 10 f − Frequency − MHz Figure 66. 30 40 50 60 HD3 70 80 HD2 100 0 100 20 90 −100 1 Differential Input to Differential Output Gain = 2 RL = 800 W RF = 1 kW f = 8 MHz VS = 5 V 10 Harmonic Distortion - dBc Harmonic Distortion − dBc −10 Harmonic Distortion − dBc 0 HARMONIC DISTORTION vs OUTPUT VOLTAGE SWING 0.5 1 1.5 2 2.5 3 0 0.5 1 1.5 2 2.5 VO − Output Voltage Swing − V VO - Output Voltage Swing - V Figure 67. Figure 68. www.BDTIC.com/TI Copyright © 2002–2008, Texas Instruments Incorporated Product Folder Link(s): THS4500 THS4501 Submit Documentation Feedback 3 17 THS4500 THS4501 SLOS350E – APRIL 2002– REVISED MAY 2008 .............................................................................................................................................................. www.ti.com TYPICAL CHARACTERISTICS: 5 V (continued) HARMONIC DISTORTION vs OUTPUT VOLTAGE SWING HARMONIC DISTORTION vs OUTPUT VOLTAGE SWING 0 −50 HD2 −60 HD3 −70 −80 20 30 40 50 HD2 60 HD3 70 80 −30 −40 −60 −80 −90 100 −100 1.5 2 2.5 3 2.5 0 3 400 800 1200 1600 RL − Load Resistance − Ω Figure 70. Figure 71. HARMONIC DISTORTION vs LOAD RESISTANCE THIRD-ORDER INTERMODULATION DISTORTION vs FREQUENCY THIRD-ORDER OUTPUT INTERCEPT POINT vs FREQUENCY HD2 -60 HD3 -70 -80 -90 0 2 Figure 69. -50 400 800 1200 1600 −50 Single-Ended Input to Differential Output Gain = 1 VO = 2 VPP Rf = 392 Ω RL = 800 Ω VS = 5 V −60 −70 −80 −90 −100 10 RL - Load Resistance - W 55 Gain = 1 VO = 2 VPP RF = 392 W RL = 800 W VS = 5 V 50 45 40 35 30 0 100 20 f − Frequency − MHz 40 60 80 100 120 f - Frequency - MHz Figure 72. Figure 73. Figure 74. SLEW RATE vs DIFFERENTIAL OUTPUT VOLTAGE STEP LARGE-SIGNAL TRANSIENT RESPONSE SMALL-SIGNAL TRANSIENT RESPONSE 1400 1200 1000 VO − Output Voltage − V Gain = 1 RL = 800 Ω Rf = 392 Ω VS = 5 V 800 600 400 200 2 0.4 1.5 0.3 VO − Output Voltage − V -100 1.5 Third-Order Output Intercept Point - dBm -40 1 VO - Output Voltage Swing - V Differential Input to Differential Output Gain = 1 VO = 2 VPP RF = 392 W f = 30 MHz VS = 5 V -30 0.5 VO − Output Voltage Swing − V 0 -20 0 HD3 −70 −100 1 HD2 −50 90 -10 SR − Slew Rate − V/ µ s −20 −90 0.5 Single-Ended Input to Differential Output Gain = 1 VO = 2 VPP Rf = 392 Ω f= 30 MHz VS = 5 V −10 Harmonic Distortion − dBc −40 Harmonic Distortion - dBc −30 Differential Input to Differential Output Gain = 2 RL = 800 W RF = 1 kW f = 30 MHz VS = 5 V 10 Third-Order Intermodulation Distortion − dBc Harmonic Distortion − dBc −20 0 Harmonic Distortion - dBc 0 0 Single-Ended Input to Differential Output Gain = 2 RL = 800 Ω Rf = 1 kΩ f = 30 MHz VS = 5 V −10 1 Gain = 1 RL = 800 Ω Rf = 392 Ω tr/tf = 300 ps VS = 5 V 0.5 0 −0.5 −1 0 0.5 1 1.5 2 2.5 VO − Differential Output Voltage Step − V Figure 75. 3 0.2 Gain = 1 RL = 800 Ω Rf = 392 Ω tr/tf = 300 ps VS = 5 V 0.1 0 −0.1 −0.2 −0.3 −1.5 0 18 HARMONIC DISTORTION vs LOAD RESISTANCE −2 −100 0 100 200 300 t − Time − ns 400 500 −0.4 −100 0 100 Figure 76. 300 400 500 Figure 77. www.BDTIC.com/TI Submit Documentation Feedback 200 t − Time − ns Copyright © 2002–2008, Texas Instruments Incorporated Product Folder Link(s): THS4500 THS4501 THS4500 THS4501 www.ti.com .............................................................................................................................................................. SLOS350E – APRIL 2002– REVISED MAY 2008 TYPICAL CHARACTERISTICS: 5 V (continued) VOLTAGE AND CURRENT NOISEvs FREQUENCY REJECTION RATIOS vs FREQUENCY 90 60 50 CMMR PSRR− 40 30 20 In 10 0.1 1 10 100 1000 0.1 1 10 f − Frequency − MHz OPEN-LOOP GAIN vs CASE TEMPERATURE 60 57 30 PIN = −30 dBm RL = 800 Ω VS = 5 V 50 RL = 800 Ω VS = 5 V 56 55 0 −30 30 −60 Phase − ° 40 Phase −90 20 Open-Loop Gain − dB Gain PIN = −20 dBm RL = 800 Ω Rf = 499 Ω VS = 5 V Open-Loop Gain − dB 54 53 52 51 50 49 48 −120 10 47 −70 0.1 1 10 f − Frequency − MHz 0 0.01 100 0.1 1 10 46 −150 1000 100 −40−30−20−100 10 20 30 40 50 60 70 80 90 Case Temperature − °C f − Frequency − MHz Figure 81. Figure 82. Figure 83. INPUT BIAS AND OFFSET CURRENT vs CASE TEMPERATURE QUIESCENT CURRENT vs SUPPLY VOLTAGE INPUT OFFSET VOLTAGE vs CASE TEMPERATURE 3.75 0 VS = 5 V 35 4 TA = 85°C IIB+ I OS − Input Offset Current − µ A −0.01 30 −0.03 IIB− 2.75 −0.04 2.5 −0.05 IOS −0.06 2 −0.07 1.75 −0.08 1.5 −0.09 Quiescent Current − mA −0.02 TA = 25°C VOS − Input Offset Voltage − mV Output Balance Error − dB Case Temperature − °C OPEN-LOOP GAIN AND PHASE vs FREQUENCY −60 I IB − Input Bias Current − µ A 0 −40−30−20−10 0 10 20 30 40 50 60 70 80 90 100 OUTPUT BALANCE ERROR vs FREQUENCY −50 2.25 RL = 800 Ω VS = 5 V Figure 80. −40 3 20 Figure 79. −30 3.25 40 Figure 78. 0 −20 PSRR+ 60 −10 10 k f − Frequency − kHz −10 PSRR− 80 RL = 800 Ω VS = 5 V 0 1 0.01 CMMR 100 70 Rejection Ratios − dB Hz I n − Current Noise − pA/ Vn 10 120 PSRR+ 80 Rejection Ratios − dB Hz Vn − Voltage Noise − nV/ 100 3.5 REJECTION RATIOS vs CASE TEMPERATURE 25 TA = −40°C 20 15 10 5 −0.1 1.25 −40−30−20−10 0 10 20 30 40 50 60 70 80 90 0 Case Temperature − °C 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 VS − Supply Voltage − ±V Figure 84. 3.5 VS = 5 V 3 2.5 2 1.5 1 0.5 0 −40 −30−20−10 0 10 20 30 40 50 60 70 80 90 Case Temperature − °C Figure 85. Figure 86. www.BDTIC.com/TI Copyright © 2002–2008, Texas Instruments Incorporated Product Folder Link(s): THS4500 THS4501 Submit Documentation Feedback 19 THS4500 THS4501 SLOS350E – APRIL 2002– REVISED MAY 2008 .............................................................................................................................................................. www.ti.com TYPICAL CHARACTERISTICS: 5 V (continued) COMMON-MODE REJECTION RATIO vs INPUT COMMON-MODE RANGE 0 150 VS = 5 V VS = 5 V 90 Source 100 Output Drive − mA 80 70 60 50 40 30 50 0 −50 20 −100 10 0 −10 −1 0 1 2 3 4 Sink −30 −40 −50 HD3-SE and Diff −60 −70 −80 −90 HD2-SE VOCM − Output Common-Mode Voltage − V Figure 87. Figure 88. Figure 89. SMALL-SIGNAL FREQUENCY RESPONSE AT VOCM OUTPUT OFFSET VOLTAGE vs OUTPUT COMMON-MODE VOLTAGE QUIESCENT CURRENT vs POWER-DOWN VOLTAGE 800 25 4 1 Quiescent Current − mA 2 VS = 5 V 600 VOS − Output Offset Voltage − mV Gain = 1 RL = 800 Ω Rf = 392 Ω PIN= −20 dBm VS = 5 V 3 HD2-Diff 1 1.25 1.5 1.75 2 2.25 2.5 2.75 3 3.25 3.5 Case Temperature − °C Input Common-Mode Range − V Small Signal Frequency Response at VOCM − dB −20 −100 −150 −40−30−20−10 0 10 20 30 40 50 60 70 80 90 5 Single-Ended and Differential Input Gain = 1 VO = 2 VPP Rf = 392 Ω f= 8 MHz, VS = 5 V −10 Harmonic Distortion − dBc CMRR − Common-Mode Rejection Ratio − dB 110 100 HARMONIC DISTORTION vs OUTPUT COMMON-MODE VOLTAGE OUTPUT DRIVE vs CASE TEMPERATURE 400 200 0 −200 0 −400 −1 20 15 10 5 −600 −2 −800 0 0 0.5 −3 0.1 1 10 100 1000 1 1.5 2 2.5 3 3.5 4 4.5 5 0 0.25 0.5 0.75 1 1.25 1.5 1.75 2 2.25 2.5 Power-down Voltage − V VOC − Output Common-Mode Voltage − V f − Frequency − MHz Figure 90. Figure 91. Figure 92. TURN-ON AND TURN-OFF DELAY TIME SINGLE-ENDED OUTPUT IMPEDANCE IN POWER-DOWN vs FREQUENCY POWER-DOWN QUIESCENT CURRENT vs CASE TEMPERATURE −2 −3 −4 −5 −6 0 0.5 1 1.5 2 2.5 3 100.5 101 t − Time − ms 102 103 Figure 93. 20 Power-Down Quiescent Current − µ A 0 0 −1 Quiescent Current − mA 0.01 ZO− Single-Ended Output Impedance in Power Down − Ω Power-Down Voltage Signal − V 1000 0.02 Current 800 1100 0.03 900 800 700 600 500 400 300 200 100 0 0.1 Gain = 1 RL = 400 Ω Rf = 499 Ω PIN = −1 dBm VS = 5 V 1 10 100 f − Frequency − MHz 1000 700 RL = 800 Ω VS = 5 V 600 500 400 300 200 100 0 −40 −30−20−10 0 10 20 30 40 50 60 70 80 90 Case Temperature − °C Figure 94. Figure 95. www.BDTIC.com/TI Submit Documentation Feedback Copyright © 2002–2008, Texas Instruments Incorporated Product Folder Link(s): THS4500 THS4501 THS4500 THS4501 www.ti.com .............................................................................................................................................................. SLOS350E – APRIL 2002– REVISED MAY 2008 TYPICAL CHARACTERISTICS: 5 V (continued) POWER-DOWN QUIESCENT CURRENT vs SUPPLY VOLTAGE Power-Down Quiescent Current − µ A 1000 900 800 700 600 500 400 300 200 100 0 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 VS − Supply Voltage − V Figure 96. www.BDTIC.com/TI Copyright © 2002–2008, Texas Instruments Incorporated Product Folder Link(s): THS4500 THS4501 Submit Documentation Feedback 21 THS4500 THS4501 SLOS350E – APRIL 2002– REVISED MAY 2008 .............................................................................................................................................................. www.ti.com APPLICATION INFORMATION FULLY DIFFERENTIAL AMPLIFIERS FULLY DIFFERENTIAL AMPLIFIER TERMINAL FUNCTIONS Differential signaling offers a number of performance advantages in high-speed analog signal processing systems, including immunity to external common-mode noise, suppression of even-order nonlinearities, and increased dynamic range. Fully differential amplifiers not only serve as the primary means of providing gain to a differential signal chain, but also provide a monolithic solution for converting single-ended signals into differential signals for easier, higher performance processing. The THS4500 family of amplifiers contains products in Texas Instruments' expanding line of high-performance, fully differential amplifiers. Information on fully differential amplifier fundamentals, as well as implementation specific information, is presented in the Applications Section of this data sheet to provide a better understanding of the operation of the THS4500 family of devices, and to simplify the design process for designs using these amplifiers. Fully differential amplifiers are typically packaged in eight-pin packages, as shown in Figure 97. The device pins include two inputs (VIN+, VIN–), two outputs (VOUT–, VOUT+), two power supplies (VS+, VS–), an output common-mode control pin (VOCM), and an optional power-down pin (PD). APPLICATIONS SECTION A standard configuration for the device is shown in Figure 97. The functionality of a fully differential amplifier can be imagined as two inverting amplifiers that share a common noninverting terminal (though the voltage is not necessarily fixed). For more information on the basic theory of operation for fully differential amplifiers, refer to the Texas Instruments application note Fully Differential Amplifiers, literature number SLOA054, available for download at www.ti.com. • • • • • • • • • • • • • • 22 Fully Differential Amplifier Terminal Functions Input Common-Mode Voltage Range and the THS4500 Family Choosing the Proper Value for the Feedback and Gain Resistors Application Circuits Using Fully Differential Amplifiers Key Design Considerations for Interfacing to an Analog-to-Digital Converter Setting the Output Common-Mode Voltage With the VOCM Input Saving Power with Power-Down Functionality Linearity: Definitions, Terminology, Circuit Techniques, and Design Tradeoffs An Abbreviated Analysis of Noise in Fully Differential Amplifiers Printed-Circuit Board Layout Techniques for Optimal Performance Power Dissipation and Thermal Considerations Power Supply Decoupling Techniques and Recommendations Evaluation Fixtures, Spice Models, and Applications Support Additional Reference Material VNI - MV CO V+S +TV UO 1 8 V +NI 2 7DP 3 6 V S- 4 5 TVUO Figure 97. Fully Differential Amplifier Pin Diagram INPUT COMMON-MODE VOLTAGE RANGE AND THE THS4500 FAMILY The key difference between the THS4500/1 and the THS4502/3 is the input common-mode range for the four devices. The THS4502 and THS4503 have an input common-mode range that is centered around midrail, and the THS4500 and THS4501 have an input common-mode range that is shifted to include the negative power-supply rail. Selection of one or the other amplifier is determined by the nature of the application. Specifically, the THS4500 and THS4501 are designed for use in single-supply applications where the input signal is ground-referenced, as depicted in Figure 98. The THS4502 and THS4503 are designed for use in single-supply or split-supply applications where the input signal is centered between the power-supply voltages, as depicted in Figure 99. www.BDTIC.com/TI Submit Documentation Feedback - Copyright © 2002–2008, Texas Instruments Incorporated Product Folder Link(s): THS4500 THS4501 THS4500 THS4501 www.ti.com .............................................................................................................................................................. SLOS350E – APRIL 2002– REVISED MAY 2008 R1G RS V OUT) + V+ S RT VS R1F –V TUO MV CO + - + R2G β) ) V–N–I 1( β ) ) V2MCO β 2β N– I)1( MV CO (3) (4) β (5) NOTE: The equations denote the device inputs as VN and VP, and the circuit inputs as VIN+ and VIN–. RG R1F RF V +NI VP + - + MV CO VN -V S R2G (2) )β V P+ V N– ) –V I)1( β ) TUO V+ S RT VS (1) Where: RG β+ R) RG F R2F R1G V– V N+ V–N–I 1( β ) ) V TUO Figure 98. Application Circuit for the THS4500 and THS4501, Featuring Single-Supply Operation With a Ground-Reference Input Signal RS + V IN)(1–β)–V IN–(1–β) ) 2V OCMβ 2β VNI - R2F Figure 99. Application Circuit for the THS4500 and THS4501, Featuring Split-Supply Operation With an Input Signal Referenced at the Midrail Equation 1 through Equation 5 are used to calculate the required input common-mode range for a given set of input conditions. The equations allow calculation of the input common-mode range requirements, given information about the input signal, the output voltage swing, the gain, and the output common-mode voltage. Calculating the maximum and minimum voltage required for VN and VP (the amplifier input nodes) determines whether or not the input common-mode range is violated or not. Four equations are required: two calculate the output voltages and two calculate the node voltages at VN and VP (note that only one of these nodes needs calculation, because the amplifier forces a virtual short between the two nodes). RG + - + TV UO - +TV UO RF Figure 100. Diagram For Input Common-Mode Range Equations Table 1 and Table 2 depict the input common-mode range requirements for two different input scenarios, an input referenced around the negative rail and an input referenced around midrail. The tables highlight the differing requirements on input common-mode range, and illustrate the reasoning to choose either the THS4500/1 or the THS4502/3. For signals referenced around the negative power supply, the THS4500/1 should be chosen because its input common-mode range includes the negative supply rail. For all other situations, the THS4502/3 offers slightly improved distortion and noise performance for applications with input signals centered between the power-supply rails. Table 1. Negative-Rail Referenced Gain (V/V) VIN+ (V) VIN– (V) VIN (VPP) VOCM (V) VOD (VPP) VNMIN (V) 1 –2.0 to 2.0 0 4 2.5 4 0.75 1.75 2 –1.0 to 1.0 0 2 2.5 4 0.5 1.167 4 –0.5 to 0.5 0 1 2.5 4 0.3 0.7 8 –0.25 to 0.25 0 0.5 2.5 4 0.167 0.389 www.BDTIC.com/TI Copyright © 2002–2008, Texas Instruments Incorporated Product Folder Link(s): THS4500 THS4501 VNMAX (V) Submit Documentation Feedback 23 THS4500 THS4501 SLOS350E – APRIL 2002– REVISED MAY 2008 .............................................................................................................................................................. www.ti.com Table 2. Midrail Referenced Gain (V/V) VIN+ (V) VIN– (V) VIN (VPP) VOD (VPP) VNMIN (V) VNMAX (V) 1 0.5 to 4.5 2.5 4 2.5 4 2 3 2 1.5 to 3.5 2.5 2 2.5 4 2.16 2.83 4 2.0 to 3.0 2.5 1 2.5 4 2.3 2.7 8 2.25 to 2.75 2.5 0.5 2.5 4 2.389 2.61 CHOOSING THE PROPER VALUE FOR THE FEEDBACK AND GAIN RESISTORS The selection of feedback and gain resistors impacts circuit performance in a number of ways. The values presented in this section provide the optimum high-frequency performance (lowest distortion, flat frequency response). Since the THS4500 family of amplifiers is developed with a voltage feedback architecture, the choice of resistor values does not have a dominant effect on bandwidth, unlike a current-feedback amplifier. However, resistor choices do have second-order effects. For optimal performance, the following feedback resistor values are recommended. In higher gain configurations (gain greater than two), the feedback resistor values have much less effect on the high-frequency performance. Example feedback and gain resistor values are given in the section on basic design considerations (Table 3). Amplifier loading, noise, and the flatness of the frequency response are three design parameters that should be considered when selecting feedback resistors. Larger resistor values contribute more noise and can induce peaking in the ac response in low gain configurations; smaller resistor values can load the amplifier more heavily, resulting in a reduction in distortion performance. In addition, feedback resistor values, coupled with gain requirements, determine the value of the gain resistors and directly impact the input impedance of the entire circuit. While there are no strict rules about resistor selection, these trends can provide qualitative design guidance. APPLICATION CIRCUITS USING FULLY DIFFERENTIAL AMPLIFIERS Fully differential amplifiers provide designers with a great deal of flexibility in a wide variety of applications. This section provides an overview of some common circuit configurations and gives some design guidelines. Designing the interface to an analog-to-digital converter (ADC), driving lines differentially, and filtering with fully differential amplifiers are a few of the circuits that are covered. 24 VOCM (V) BASIC DESIGN CONSIDERATIONS The circuits in Figure 98 through Figure 100 are used to highlight basic design considerations for fully differential amplifier circuit designs. Table 3. Resistor Values for Balanced Operation in Various Gain Configurations niaG R2 and R4 (Ω) R1 (Ω) R3 (Ω) RT (Ω) 1 392 412 383 54.9 1 499 523 487 53.6 2 392 215 187 60.4 2 1.3 k 665 634 52.3 5 1.3 k 274 249 56.2 ǒ Ǔ VDO VNI 5 3.32 k 681 649 52.3 10 1.3 k 147 118 64.9 10 6.81 k 698 681 52.3 Equations for calculating fully differential amplifier resistor values in order to obtain balanced operation in the presence of a 50-Ω source impedance are given in Equation 6 through Equation 9. 1 K+2R 2R +4R R T+ 1R K –1 1 – 1(2 ))K ǒ Rs || T Ǔ RS 3R 3R +1R * R (6) 1R β+ 1 1R )2R 3R ) RRT || S β+ 2 3R ) RRT || S)4R VDO –1 β 2 + 2 β) β2 VS 1 VDO + V NI ǒ ǒǓ –1 β Ǔ 2ǒ β) β RT R) R T Ǔ S (8) 2 1 2 (9) For more detailed information about balance in fully differential amplifiers, see the application report, Fully Differential Amplifiers (SLOA054), referenced at the end of this data sheet. www.BDTIC.com/TI Submit Documentation Feedback (7) Copyright © 2002–2008, Texas Instruments Incorporated Product Folder Link(s): THS4500 THS4501 THS4500 THS4501 www.ti.com .............................................................................................................................................................. SLOS350E – APRIL 2002– REVISED MAY 2008 INTERFACING TO AN ANALOG-TO-DIGITAL CONVERTER The THS4500 family of amplifiers are designed specifically to interface to today's highest-performance ADCs. This section highlights the key concerns when interfacing to an ADC and provides example interface circuits. There are several key design concerns when interfacing to an analog-to-digital converter: • Terminate the input source properly. In high-frequency receiver chains, the source that feeds the fully differential amplifier requires a specific load impedance (that is, 50 Ω). • Design a symmetric printed circuit board (PCB) layout. Even-order distortion products are heavily influenced by layout, and careful attention to a symmetric layout minimizes these distortion products. • Minimize inductance in power-supply decoupling traces and components. Poor power-supply decoupling can have a dramatic effect on circuit performance. Since the outputs are differential, differential currents exist in the power-supply pins. Thus, decoupling capacitors should be placed in a manner that minimizes the impedance of the current loop. • Use separate analog and digital power supplies and grounds. Noise (bounce) in the power supplies (created by digital switching currents) can couple directly into the signal path, and power-supply noise can create higher distortion products as well. • Use care when filtering. While an RC low-pass filter may be desirable on the output of the amplifier to filter broadband noise, the excess loading can negatively impact the amplifier linearity. Filtering in the feedback path does not have this effect. • AC-coupling allows easier circuit design. If dc-coupling is required, be aware of the excess power dissipation that can occur due to level-shifting the output through the output common-mode voltage control. • Do not terminate the output unless required. Many open-loop, class-A amplifiers require 50-Ω termination for proper operation, but closed-loop fully differential amplifiers drive a specific output voltage regardless of the load impedance present. Terminating the output of a fully differential amplifier with a heavy load adversely affects the amplifier linearity. • Comprehend the VOCM input drive requirements. Determine if the ADC voltage reference can provide the required amount of current to move VOCM to the desired value. A buffer may be needed. • • • • Decouple the VOCM pin to eliminate the antenna effect. VOCM is a high-impedance node that can act as an antenna. A large decoupling capacitor on this node eliminates this problem. Know the input common-mode range. If the input signal is referenced around the negative power-supply rail (for example, around ground on a single 5 V supply), then the THS4500/1 accommodates the input signal. If the input signal is referenced around midrail, choose the THS4502/3 for the best operation. Packaging makes a difference at higher frequencies. If possible, choose the smaller, thermally-enhanced MSOP package for the best performance. As a rule, lower junction temperatures provide better performance. If possible, use a thermally-enhanced package, even if the power dissipation is relatively small compared to the maximum power dissipation rating to achieve the best results. Understand the effect of the load impedance seen by the fully differential amplifier when performing system-level intercept point calculations. Lighter loads (such as those presented by an ADC) allow smaller intercept points to support the same level of intermodulation distortion performance. EXAMPLE ANALOG-TO-DIGITAL CONVERTER DRIVER CIRCUITS The THS4500 family of devices is designed to drive high-performance ADCs with extremely high linearity, allowing for the maximum effective number of bits at the output of the data converter. Two representative circuits shown below highlight single-supply operation and split supply operation, respectively. Specific feedback resistor, gain resistor, and feedback capacitor values are not shown, as these values depend on the frequency of interest. Information on calculating these values can be found in the applications material above. CF RS RG RF V5 VS RT V5 01 mF 1.0 1 mF RG + MV CO + 3054SHT V 5 01 mF 1.0 mF R OSI I DA 014N 5S SPSM 08/tiB-21 NI R OSI MC mF 1.0 mF RF CF Figure 101. Using the THS4503 With the ADS5410 www.BDTIC.com/TI Copyright © 2002–2008, Texas Instruments Incorporated Product Folder Link(s): THS4500 THS4501 Submit Documentation Feedback 25 THS4500 THS4501 SLOS350E – APRIL 2002– REVISED MAY 2008 .............................................................................................................................................................. www.ti.com FILTERING WITH FULLY DIFFERENTIAL AMPLIFIERS CF RS RG RF V5 VS RT V5 01 mF 1.0 + MV CO R OSI 12N 45I SDA SPSM 04/tiB-41 NI R OSI + - 1 mF mF 1054SHT MC RG RF CF 1.0 mF Similar to single-ended counterparts, fully differential amplifiers have the ability to couple filtering functionality with voltage gain. Numerous filter topologies can be based on fully differential amplifiers. Several of these are outlined in the application report A Differential Circuit Collection (literature number SLOA064), referenced at the end of this data sheet. The circuit below depicts a simple, two-pole, low-pass filter applicable to many different types of systems. The first pole is set by the resistors and capacitors in the feedback paths, and the second pole is set by the isolation resistors and the capacitor across the outputs of the isolation resistors. Figure 102. Using the THS4501 With the ADS5421 C1F FULLY DIFFERENTIAL LINE DRIVERS The THS4500 family of amplifiers can be used as high-frequency, high-swing differential line drivers. The high power-supply voltage rating (16.5 V absolute maximum) allows operation on a single 12-V or a single 15-V supply. The high supply voltage, coupled with the ability to provide differential outputs, enables the ability to drive 26 VPP into reasonably heavy loads (250 Ω or greater). The circuit in Figure 103 illustrates the THS4500 family of devices used as high-speed line drivers. For line driver applications, close attention must be paid to thermal design constraints because of the typically high level of power dissipation. CG RS VS RG RF V 51 RT CS R OSI + MV CO 2/0054SHT RL V DD + 1.0 mF R OSI RF RG CS V 62 = DO R1G RS PP CG R1F R OSI RT VS + - C VO + R2G R OSI R2F C2F Figure 104. A Two-Pole, Low-Pass Filter Design Using a Fully Differential Amplifier With Poles Located at: P1 = (2πRFCF)–1 in Hz and P2 = (4πRISOC)–1 in Hz Often, filters like these are used to eliminate broadband noise and out-of-band distortion products in signal acquisition systems. It should be noted that the increased load placed on the output of the amplifier by the second low-pass filter has a detrimental effect on the distortion performance. The preferred method of filtering is to use the feedback network, as the typically smaller capacitances required at these points in the circuit do not load the amplifier nearly as heavily in the passband. Figure 103. Fully Differential Line Driver With High Output Swing 26 www.BDTIC.com/TI Submit Documentation Feedback Copyright © 2002–2008, Texas Instruments Incorporated Product Folder Link(s): THS4500 THS4501 THS4500 THS4501 www.ti.com .............................................................................................................................................................. SLOS350E – APRIL 2002– REVISED MAY 2008 SETTING THE OUTPUT COMMON-MODE VOLTAGE WITH THE VOCM INPUT The output common-mode voltage pin provides a critical function to the fully differential amplifier; it accepts an input voltage and reproduces that input voltage as the output common-mode voltage. In other words, the VOCM input provides the ability to level-shift the outputs to any voltage inside the output voltage swing of the amplifier. A description of the input circuitry of the VOCM pin is shown in Figure 105 to facilitate an easier understanding of the VOCM interface requirements. The VOCM pin has two 50-kΩ resistors between the power supply rails to set the default output common-mode voltage to midrail. A voltage applied to the VOCM pin alters the output common-mode voltage as long as the source has the ability to provide enough current to overdrive the two 50-kΩ resistors. This phenomenon is depicted in the VOCM equivalent circuit diagram. Current drive is especially important when using the reference voltage of an analog-to-digital converter to drive VOCM. Output current drive capabilities differ from part to part, so a voltage buffer may be necessary in some applications. Since the VOCM pin provides the ability to set an output common-mode voltage, the ability for increased power dissipation exists. While this possibility does not pose a performance problem for the amplifier, it can cause additional power dissipation of which the system designer should be aware. The circuit shown in Figure 106 demonstrates an example of this phenomenon. For a device operating on a single 5-V supply with an input signal referenced around ground and an output common-mode voltage of 2.5 V, a dc potential exists between the outputs and the inputs of the device. The amplifier sources current into the feedback network in order to provide the circuit with the proper operating point. While there are no serious effects on the circuit performance, the extra power dissipation may need to be included in the system power budget. I1 = MV CO R1FR + 1GR + R S || dnuorG ot htaP tnerruC CD R1F R1G RS + - = W NI I MV CO k 05 = R RL + - V+S NI I CD V-5.2 V5 RT VS MV CV O 5.2 k 05 = R T = V 2MCO R2G - V+S - V S R I2 = Figure 105. Equivalent Input Circuit for VOCM CD V-5.2 dnuorG ot htaP tnerruC CD W VS- R2F MV CO R2FR + 2G Figure 106. Depiction of DC Power Dissipation Caused By Output Level-Shifting in a DC-Coupled Circuit By design, the input signal applied to the VOCM pin propagates to the outputs as a common-mode signal. As shown in Figure 105, the VOCM input has a high impedance associated with it, dictated by the two 50-kΩ resistors. While the high impedance allows for relaxed drive requirements, it also allows the pin and any associated PCB traces to act as an antenna. For this reason, a decoupling capacitor is recommended on this node for the sole purpose of filtering any high-frequency noise that could couple into the signal path through the VOCM circuitry. A 0.1-µF or 1-µF capacitance is a reasonable value for eliminating a great deal of broadband interference, but additional, tuned decoupling capacitors should be considered if a specific source of electromagnetic or radio frequency interference is present elsewhere in the system. Information on the ac performance (bandwidth, slew rate) of the VOCM circuitry is included in the Electrical Characteristics and Typical Characterisitcs sections. www.BDTIC.com/TI Copyright © 2002–2008, Texas Instruments Incorporated Product Folder Link(s): THS4500 THS4501 Submit Documentation Feedback 27 THS4500 THS4501 SLOS350E – APRIL 2002– REVISED MAY 2008 .............................................................................................................................................................. www.ti.com The THS4500 family of fully differential amplifiers contains devices that come with and without the power-down option. Even-numbered devices have power-down capability, which is described in detail here. The power-down pin of the amplifiers defaults to the positive supply voltage in the absence of an applied voltage (that is, an internal pull-up resistor is present), putting the amplifier in the power-on mode of operation. To turn off the amplifier in an effort to conserve power, the power-down pin can be driven towards the negative rail. The threshold voltages for power-on and power-down are relative to the supply rails and given in the specification tables. Above the enable threshold voltage, the device is on. Below the disable threshold voltage, the device is off. Behavior between these threshold voltages is not specified. Note that this power-down functionality is just that; the amplifier consumes less power in power-down mode. The power-down mode is not intended to provide a high-impedance output. In other words, the power-down functionality is not intended to allow use as a 3-state bus driver. When in power-down mode, the impedance looking back into the output of the amplifier is dominated by the feedback and gain setting resistors. The time delays associated with turning the device on and off are specified as the time it takes for the amplifier to reach 50% of the nominal quiescent current. The time delays are on the order of microseconds because the amplifier moves in and out of the linear mode of operation in these transitions. Intercept points are specifications that have long been used as key design criteria in the RF communications world as a metric for the intermodulation distortion performance of a device in the signal chain (for example, amplifiers, mixers, etc.). Use of the intercept point, rather than strictly the intermodulation distortion, allows for simpler system-level calculations. Intercept points, like noise figures, can be easily cascaded back and forth through a signal chain to determine the overall receiver chain intermodulation distortion performance. The relationship between intermodulation distortion and intercept point is depicted in Figure 107 and Figure 108. PO PO ∆ fc =1f c− f −∆2fc = rewoP SAVING POWER WITH POWER-DOWN FUNCTIONALITY c DMI P 3= PS 3ffc− 1f ∆ f PS − O PS f c 2f 3 c+ ∆f zHM − ycneuqerF − f Figure 107. 2-Tone and 3rd-Order Intermodulation Products LINEARITY: DEFINITIONS, TERMINOLOGY, CIRCUIT TECHNIQUES, AND DESIGN TRADEOFFS The THS4500 family of devices features unprecedented distortion performance for monolithic fully differential amplifiers. This section focuses on the fundamentals of distortion, circuit techniques for reducing nonlinearity, and methods for equating distortion of fully differential amplifiers to desired linearity specifications in RF receiver chains. Amplifiers are generally thought of as linear devices. In other words, the output of an amplifier is a linearly scaled version of the input signal applied to it. In reality, however, amplifier transfer functions are nonlinear. Minimizing amplifier nonlinearity is a primary design goal in many applications. 28 www.BDTIC.com/TI Submit Documentation Feedback Copyright © 2002–2008, Texas Instruments Incorporated Product Folder Link(s): THS4500 THS4501 THS4500 THS4501 www.ti.com .............................................................................................................................................................. SLOS350E – APRIL 2002– REVISED MAY 2008 OIP 3 + P O ) TP UO )mBd( PIO X1 P gO+ ol 01 3 ǒŤIMD2 ŤǓ where ǒ 3 2 ff i d P V R2 1L00.0 R ,enot elgnis a fo rPew:oEpTO tuN ptuo eht soi Vla dintn ae,e recfnfiadtsiser daol .enot elgnis a rokfaeegpatlov PO DMI PII 3 3 X3 PNI )mBd( PS (10) Ǔ )ffid(Peht si eht sLi laitfnideref (11) As can be seen in the equations, when a higher impedance is used, the same level of intermodulation distortion performance results in a lower intercept point. Therefore, it is important to understand the impedance seen by the output of the fully differential amplifier when selecting a minimum intercept point. Figure 109 shows the relationship between the strict definition of an intercept point with a normalized, or equivalent, intercept point for the THS4500. 06 Due to the intercept point ease-of-use in system level calculations for receiver chains, it has become the specification of choice for guiding distortion-related design decisions. Traditionally, these systems use primarily class-A, single-ended RF amplifiers as gain blocks. These RF amplifiers are typically designed to operate in a 50-Ω environment, just like the rest of the receiver chain. Since intercept points are given in dBm, this implies an associated impedance (50 Ω). However, with a fully differential amplifier, the output does not require termination as an RF amplifier would. Because closed-loop amplifiers deliver signals to the outputs regardless of the impedance present, it is important to comprehend this feature when evaluating the intercept point of a fully differential amplifier. The THS4500 series of devices yields optimum distortion performance when loaded with 200 Ω to 1 kΩ, very similar to the input impedance of an analog-to-digital converter over its input frequency band. As a result, terminating the input of the ADC to 50 Ω can actually be detrimental to system performance. This discontinuity between open-loop, class-A amplifiers and closed-loop, class-AB amplifiers becomes apparent when comparing the intercept points of the two types of devices. Equation 10 gives the definition of an intercept point, relative to the intermodulation distortion. 002 ot dezilamroN 55 05 ot dezilamroN 05 Ω Ω 54 04 53 PIO 0R Ω 308L= 03 1 = niaG 52 293 R =f Ω V S= V±5 02 zHk 002 = gnicapS en To 51 06 05 04 03 02 01 0 001 09 08 07 mBd − tnioP tpecretnI tuptuO redP rO -drih3T − IO Figure 108. Graphical Representation of 2-Tone and 3rd-Order Intercept Point zHM − ycneuqerF − f Figure 109. Equivalent 3rd-Order Intercept Point for the THS4500 Comparing specifications between different device types becomes easier when a common impedance level is assumed. For this reason, the intercept points on the THS4500 family of devices are reported normalized to a 50-Ω load impedance. AN ANALYSIS OF NOISE IN FULLY DIFFERENTIAL AMPLIFIERS Noise analysis in fully differential amplifiers is analogous to noise analysis in single-ended amplifiers; the same concepts apply. Figure 110 shows a generic circuit diagram consisting of a voltage source, a termination resistor, two gain setting resistors, two feedback resistors, and a fully differential amplifier is shown, including all the relevant noise sources. From this circuit, the noise factor (F) and noise figure (NF) are calculated. The figures indicate the appropriate scaling factor for each of the noise sources in two different cases. The first case includes the termination resistor, and the www.BDTIC.com/TI Copyright © 2002–2008, Texas Instruments Incorporated Product Folder Link(s): THS4500 THS4501 Submit Documentation Feedback 29 THS4500 THS4501 SLOS350E – APRIL 2002– REVISED MAY 2008 .............................................................................................................................................................. www.ti.com second, simplified case assumes that the voltage source is properly terminated by the gain-setting resistors. With these scaling factors, the amplifier input noise power (NA) can be calculated by summing each individual noise source with its scaling factor. The noise delivered to the amplifier by the source (NI) and input noise power are used to calculate the noise factor and noise figure as shown in Equation 23 through Equation 27. N i eg NA Rg R f ef Scaling Factors for Individual Noise Sources Asseming No Termination Resistance is Used (that is, RT is Open) NA: Fully Differential Amplifier; termination = 2Rg Noise Source 2 ȡR ) ȧR R Ȣ (eni)2 i(in )2 f RTk4 Rs 2 f es So (20) ǒRR Ǔ 2 g (21) ȡ R ȣ ȧ R ) Rȧ 2Ȥ Ȣ g No RTk4 2 g s g (22) Input Noise With a Termination Resistor iii Rg (19) f et eg (18) 2 ffid-ylluf pma − iin s 2 R g2 )2 + R t g R g2 en No ȣ Rȧ ) Ȥ Rg g i( ii S i N i Scale Factor 2 R f ef ȡ R2 R ȣ ȧ R)R2 ȧ ȧ R ) R2 R ȧ ȧ R)R2 ȧ Ȣ Ȥ t g NR + i Tk4 g t s t g s t Figure 110. Noise Sources in a Fully Differential Amplifier Circuit g (23) Input Noise Assuming No Termination Resistor Scaling Factors for Individual Noise Sources 2 R2 G Assuming a Finite Value Termination Resistor RTk4 = N S i aitnereffiD yllN uF R2G + R S A: (24) esioN ecruoro StcaF elacS )rotc2aF elacS ȡR ȣ R ) ȧR R) RR ȧ ǒ )R Ǔ 2R Ȣ Ȥ g g e( in )2 s f i(in )2 R g2 i( ii)2 R g2 g t s t Noise Factor and Noise Figure Calculations ecruoS e´sioN( = N A S NA +1=F N I (12) )FFN( g+ ol 01 (25) (26) (27) (13) (14) ȡ RR2)RR2 ȣ ȧ R ) R2 R ȧ Ȣ R )R2 Ȥ 2 s G RTk4 s t g s g t RTk4 f 2 s g ǒRR Ǔ (15) 2 g f (16) 2 RTk4 30 g ȡ 2 ȧR ) Ȣ g ȣ RR ȧ ǒ )R Ǔ 2R Ȥ R g s s t t (17) www.BDTIC.com/TI Submit Documentation Feedback Copyright © 2002–2008, Texas Instruments Incorporated Product Folder Link(s): THS4500 THS4501 THS4500 THS4501 www.ti.com .............................................................................................................................................................. SLOS350E – APRIL 2002– REVISED MAY 2008 PRINTED CIRCUIT BOARD LAYOUT TECHNIQUES FOR OPTIMAL PERFORMANCE Achieving optimum performance with high frequency amplifier-like devices in the THS4500 family requires careful attention to PCB layout parasitic and external component types. Recommendations that optimize performance include: • Minimize parasitic capacitance to any ac ground for all of the signal I/O pins. Parasitic capacitance on the output and input pins can cause instability. To reduce unwanted capacitance, a window around the signal I/O pins should be opened in all of the ground and power planes around those pins. Otherwise, ground and power planes should be unbroken elsewhere on the board. • Minimize the distance (< 0.25”, 6.35 mm) from the power-supply pins to high frequency 0.1-µF decoupling capacitors. At the device pins, the ground and power-plane layout should not be in close proximity to the signal I/O pins. Avoid narrow power and ground traces to minimize inductance between the pins and the decoupling capacitors. The power supply connections should always be decoupled with these capacitors. Larger (6.8 µF or more) tantalum decoupling capacitors, effective at lower frequency, should also be used on the main supply pins. These may be placed somewhat farther from the device and may be shared among several devices in the same area of the PCB. The primary goal is to minimize the impedance seen in the differential-current return paths. • Careful selection and placement of external components preserve the high-frequency performance of the THS4500 family. Resistors should be a very low reactance type. Surface-mount resistors work best and allow a tighter overall layout. Metal-film and carbon composition, axially-leaded resistors can also provide good high frequency performance. Again, keep the leads and PCB trace length as short as possible. Never use wirewound type resistors in a high-frequency application. Since the output pin and inverting input pins are the most sensitive to parasitic capacitance, always position the feedback and series output resistors, if any, as close as possible to the inverting input pins and output pins. Other network components, such as input termination resistors, should be placed close to the gain-setting resistors. Even with a low parasitic capacitance shunting the external resistors, excessively high resistor values can create significant time constants that can degrade performance. Good axial metal-film or surface-mount resistors have approximately 0.2 pF in shunt with the resistor. For resistor • • • • values greater than 2.0 kΩ, this parasitic capacitance can add a pole and/or a zero below 400 MHz that can affect circuit operation. Keep resistor values as low as possible, consistent with load driving considerations. Connections to other wideband devices on the board may be made with short direct traces or through onboard transmission lines. For short connections, consider the trace and the input to the next device as a lumped capacitive load. Relatively wide traces (50 mils to 100 mils, or 1.27 mm to 2.54 mm) should be used, preferably with ground and power planes opened up around them. Estimate the total capacitive load and determine if isolation resistors on the outputs are necessary. Low parasitic capacitive loads (less than 4 pF) may not need an RS since the THS4500 family is nominally compensated to operate with a 2-pF parasitic load. Higher parasitic capacitive loads without an RS are allowed as the signal gain increases (increasing the unloaded phase margin). If a long trace is required, and the 6-dB signal loss intrinsic to a doubly-terminated transmission line is acceptable, implement a matched impedance transmission line using microstrip or stripline techniques (consult an ECL design handbook for microstrip and stripline layout techniques). A 50-Ω environment is normally not necessary onboard, and in fact, a higher impedance environment improves distortion as shown in the distortion versus load plots. With a characteristic board trace impedance defined based onboard material and trace dimensions, a matching series resistor into the trace from the output of the THS4500 family is used as well as a terminating shunt resistor at the input of the destination device. Remember also that the terminating impedance is the parallel combination of the shunt resistor and the input impedance of the destination device: this total effective impedance should be set to match the trace impedance. If the 6-dB attenuation of a doubly-terminated transmission line is unacceptable, a long trace can be series-terminated at the source end only. Treat the trace as a capacitive load in this case. This configuration does not preserve signal integrity as well as a doubly-terminated line. If the input impedance of the destination device is low, there is some signal attenuation due to the voltage divider formed by the series output into the terminating impedance. Socketing a high-speed part such as the THS4500 family is not recommended. The additional lead length and pin-to-pin capacitance introduced by the socket can create an extremely troublesome parasitic network that can make it almost www.BDTIC.com/TI Copyright © 2002–2008, Texas Instruments Incorporated Product Folder Link(s): THS4500 THS4501 Submit Documentation Feedback 31 THS4500 THS4501 SLOS350E – APRIL 2002– REVISED MAY 2008 .............................................................................................................................................................. www.ti.com impossible to achieve a smooth, stable frequency response. Best results are obtained by soldering the THS4500 family parts directly onto the board. 502.0 060.0 710.0 PowerPAD DESIGN CONSIDERATIONS The THS4500 family is available in a thermally-enhanced PowerPAD set of packages. These packages are constructed using a downset leadframe upon which the die is mounted [see Figure 111(a) and Figure 111(b)]. This arrangement results in the lead frame being exposed as a thermal pad on the underside of the package [see Figure 111(c)]. Because this thermal pad has direct thermal contact with the die, excellent thermal performance can be achieved by providing a good thermal path away from the thermal pad. The PowerPAD package allows for both assembly and thermal management in one manufacturing operation. During the surface-mount solder operation (when the leads are being soldered), the thermal pad can also be soldered to a copper area underneath the package. Through the use of thermal paths within this copper area, heat can be conducted away from the package into either a ground plane or other heat dissipating device. The PowerPAD package represents a breakthrough in combining the small area and ease of assembly of surface mount with the, heretofore, awkward mechanical methods of heatsinking. EID V ediS)a( wei lamrehT daP EID V dnE)b( wei V mottoB )c( wei Figure 111. Views of PowerPAD, Thermally-Enhanced Package Although there are many ways to properly heatsink the PowerPAD package, the following steps illustrate the recommended approach. 32 1 niP 310.0 030.0 570.0 520.0 490.0 530.0 010.0 saiv Vp To wei Figure 112. PowerPAD PCB Etch and Via Pattern PowerPAD PCB LAYOUT CONSIDERATIONS 1. Prepare the PCB with a top side etch pattern as shown in Figure 112. There should be etch for the leads as well as etch for the thermal pad. 2. Place five holes in the area of the thermal pad. These holes should be 13 mils (0.33 mm) in diameter. Keep them small so that solder wicking through the holes is not a problem during reflow. 3. Additional vias may be placed anywhere along the thermal plane outside of the thermal pad area. These holes help dissipate the heat generated by the THS4500 family IC. These additional vias may be larger than the 13-mil diameter vias directly under the thermal pad. They can be larger because they are not in the thermal pad area to be soldered so that wicking is not a problem. 4. Connect all holes to the internal ground plane. 5. When connecting these holes to the ground plane, do not use the typical web or spoke via connection methodology. Web connections have a high thermal resistance connection that is useful for slowing the heat transfer during soldering operations. This transfer slowing makes the soldering of vias that have plane connections easier. In this application, however, low thermal resistance is desired for the most efficient heat transfer. Therefore, the holes under the THS4500 family PowerPAD package should make their connection to the internal ground plane with a complete connection around the entire circumference of the plated-through hole. www.BDTIC.com/TI Submit Documentation Feedback 040.0 Copyright © 2002–2008, Texas Instruments Incorporated Product Folder Link(s): THS4500 THS4501 THS4500 THS4501 www.ti.com .............................................................................................................................................................. SLOS350E – APRIL 2002– REVISED MAY 2008 Figure 113 for the two packages. The data for the DGN package assumes a board layout that follows the PowerPAD layout guidelines referenced above and detailed in the PowerPAD application notes in the Additional Reference Material section at the end of the data sheet. 5.3 egakcaP NGD niP-8 3 5.2 2 egakcaP D niP-8 5.1 1 POWER DISSIPATION AND THERMAL CONSIDERATIONS The THS4500 family of devices does not incorporate automatic thermal shutoff protection, so the designer must take care to ensure that the design does not violate the absolute maximum junction temperature of the device. Failure may result if the absolute maximum junction temperature of +150°C is exceeded. For best performance, design for a maximum junction temperature of +125°C. Between +125°C and +150°C, damage does not occur, but the performance of the amplifier begins to degrade. = The thermal characteristics of the device are dictated by the package and the PCB. Maximum power dissipation for a given package can be calculated using the following formula. TA TAM X xP amD qAJ (28) Where: PDmax is the maximum power dissipation in the amplifier (W). TMAX is the absolute maximum junction temperature (°C). TA is the ambient temperature (°C). θJA = θJC + θCA θJC is the thermal coefficient from the silicon junctions to the case (°C/W). θCA is the thermal coefficient from the case to ambient air (°C/W). For systems where heat dissipation is more critical, the THS4500 family of devices is offered in an MSOP-8 package with PowerPAD. The thermal coefficient for the MSOP PowerPAD package is substantially improved over the traditional SOIC. Maximum power dissipation levels are depicted in 5.0 02 0 W − noitapissiD rewoP mumixPaD M− 6. The top-side solder mask should leave the terminals of the package and the thermal pad area with its five holes exposed. The bottom-side solder mask should cover the five holes of the thermal pad area. This configuration prevents solder from being pulled away from the thermal pad area during the reflow process. 7. Apply solder paste to the exposed thermal pad area and all of the IC terminals. 8. With these preparatory steps in place, the IC is simply placed in position and run through the solder reflow operation as any standard surface-mount component. This process results in a part that is properly installed. 02− 0 04− 08 06 T tneibmA TA−− erutarepme 04 °C )D( CIOS n0i7A P θ1J-8=rof W/°C )NGD( POSM4n.8A iθP 5J-= 8 rof W/°C w 05 o1 Τ lfrJ=iA oN ,°C Figure 113. Maximum Power Dissipation vs Ambient Temperature When determining whether or not the device satisfies the maximum power dissipation requirement, it is important to not only consider quiescent power dissipation, but also dynamic power dissipation. Often times, this consideration is difficult to quantify because the signal pattern is inconsistent; an estimate of the RMS power dissipation can provide visibility into a possible problem. DRIVING CAPACITIVE LOADS High-speed amplifiers are typically not well-suited for driving large capacitive loads. If necessary, however, the load capacitance should be isolated by two isolation resistors in series with the output. The requisite isolation resistor size depends on the value of the capacitance, but 10 Ω to 25 Ω is a good place to begin the optimization process. Larger isolation resistors decrease the amount of peaking in the frequency response induced by the capacitive load, but this decreased peaking comes at the expense ofa larger voltage drop across the resistors, increasing the output swing requirements of the system. www.BDTIC.com/TI Copyright © 2002–2008, Texas Instruments Incorporated Product Folder Link(s): THS4500 THS4501 Submit Documentation Feedback 33 THS4500 THS4501 SLOS350E – APRIL 2002– REVISED MAY 2008 .............................................................................................................................................................. www.ti.com RF VS VS RG RS RISO + - RT CL + THS4501 product folder on the Texas Instruments web site, www.ti.com, or through your local Texas Instruments sales representative. A schematic for the evaluation board is shown in Figure 115 with the default component values. Unpopulated footprints are shown to provide insight into design flexibility. RISO -VS 4C 5080C Riso = 10 - 25 W 4R RF 5080R RG 1J 1C Figure 114. Use of Isolation Resistors With a Capacitive Load 5080C 1R 6021R 5080C 2R 5080R 2C 5080R DP V S 1U X3054SHT 1 _ 7 8 + 3R 6 2daPrwP MV CO POWER-SUPPLY DECOUPLING TECHNIQUES AND RECOMMENDATIONS Power-supply decoupling is a critical aspect of any high-performance amplifier design process. Careful decoupling provides higher quality ac performance (most notably improved distortion performance). The following guidelines ensure the highest level of performance. 1. Place decoupling capacitors as close to the power-supply inputs as possible, with the goal of minimizing the inductance of the path from ground to the power supply. 2. Placement priority should be as follows: smaller capacitors should be closer to the device. 3. Use of solid power and ground planes is recommended to reduce the inductance along power-supply return current paths. 4. Recommended values for power-supply decoupling include 10-µF and 0.1-µF capacitors for each supply. A 1000-pF capacitor can be used across the supplies as well for extremely high frequency return currents, but often is not required. EVALUATION FIXTURES, SPICE MODELS, AND APPLICATIONS SUPPORT Texas Instruments is committed to providing its customers with the highest quality of applications support. To support this goal, an evaluation board has been developed for the THS4500 family of fully differential amplifiers. The evaluation board can be obtained by ordering through the THS4500 or 34 -V S 2J 3J 3J 55R080R 3C 5080C 2J 4J 8R 4 5080R 9R 3J 5080R 5080R 9R 3 5 6 1T 11R 6021R 1 Figure 115. Simplified Schematic of the Evaluation Board Computer simulation of circuit performance using SPICE is often useful when analyzing the performance of analog circuits and systems. This practice is particularly true for video and RF amplifier circuits where parasitic capacitance and inductance can have a major effect on circuit performance. A SPICE model for the THS4500 family of devices is available through either the Texas Instruments web site (www.ti.com) or as one model on a disk from the Texas Instruments Product Information Center (1-800-548-6132). The PIC is also available for design assistance and detailed product information at this number. These models do a good job of predicting small-signal ac and transient performance under a wide variety of operating conditions. They are not intended to model the distortion characteristics of the amplifier, nor do they attempt to distinguish between the package types in their small-signal ac performance. Detailed information about what is and is not modeled is contained in the model file itself. www.BDTIC.com/TI Submit Documentation Feedback 2J 5C 4 6R 5080C 5080R 7C 5080C 50580R 7R 6C 5080C Copyright © 2002–2008, Texas Instruments Incorporated Product Folder Link(s): THS4500 THS4501 THS4500 THS4501 www.ti.com .............................................................................................................................................................. SLOS350E – APRIL 2002– REVISED MAY 2008 ADDITIONAL REFERENCE MATERIAL • • • • • • • PowerPAD Made Easy, application brief, Texas Instruments Literature Number SLMA004. PowerPAD Thermally-Enhanced Package, technical brief, Texas Instruments Literature Number SLMA002. Karki, James. Fully Differential Amplifiers. application report, Texas Instruments Literature Number SLOA054D. Karki, James. Fully Differential Amplifiers Applications: Line Termination, Driving High-Speed ADCs, and Differential Transmission Lines. Texas Instruments Analog Applications Journal, February 2001. Carter, Bruce. A Differential Op-Amp Circuit Collection. application report, Texas Instruments Literature Number SLOA064. Carter, Bruce. Differential Op-Amp Single-Supply Design Technique, application report, Texas Instruments Literature Number SLOA072. Karki, James. Designing for Low Distortion with High-Speed Op Amps. Texas Instruments Analog Applications Journal, July 2001. Revision History Changes from Revision D (January 2004) to Revision E ............................................................................................... Page • • • • • • • • • • • • • • • • • • • • • • Updated document format ..................................................................................................................................................... 1 Clarified cross-references throughout the document............................................................................................................. 1 Added footnote 1 to Package/Ordering Information table ..................................................................................................... 3 Changed x-axis of Figure 27................................................................................................................................................ 12 Updated crossreferences for Figure 97 in first two paragraphs of the Fully Differential Amplifier Terminal Functions section.................................................................................................................................................................................. 22 Added available for download at www.ti.com and end of second paragraph of the Fully Differential Amplifier Terminal Functions section .................................................................................................................................................. 22 Changed allow for calculation of to are used to calculate in second paragraph of Input Common-Mode Voltage Range and the THS4500 Family section ............................................................................................................................. 22 Clarified last sentence of third paragraph of Input Common-Mode Voltage Range and the THS4500 Family section ...... 22 Changed two to four in first sentence of Input Common-Mode Voltage Range and the THS4500 Family section ............ 22 Corrected title of Basic Design Considerations section....................................................................................................... 24 Clarified cross-references of the circuits mentioned in the first sentence of the Basic Design Considerations section ..... 24 Deleted figure from Basic Design Considerations section................................................................................................... 24 Corrected cross-references in first sentence of Basic Design Considerations section ....................................................... 24 Clarified the Interfacing to an Analog-to-Digital Converter section...................................................................................... 25 Removed cross-reference to nonexistant tble in second paragraph of Setting the Output Common-Mode Voltage with the VOCM Input section .................................................................................................................................................. 27 Added caption titles to figures in the Linearity: Definitions, Terminology, Circuit Techniques, and Design Treadeoffs section.................................................................................................................................................................................. 28 Changed THS4502 to THS4500 in seventh paragraph of Linearity: Definitions, Terminology, Circuit Techniques, and Design Treadeoffs section ................................................................................................................................................... 28 Corrected spelling in title of An Analysis of Noise in Fully Differential Amplifiers section ................................................... 29 Added 6.35 mm to second bullet of Printed Circuit Board Layout Techniques for Optimal Performance list ..................... 31 Added 1.27 mm to 2.54 mm to fourth bullet of Printed Circuit Board Layout Techniques for Optimal Performance list .... 31 Added 0.33 mm to second list item in the PowerPAD PCB Layout Considerations section ............................................... 32 Changed title of Figure 115 ................................................................................................................................................. 34 www.BDTIC.com/TI Copyright © 2002–2008, Texas Instruments Incorporated Product Folder Link(s): THS4500 THS4501 Submit Documentation Feedback 35 PACKAGE OPTION ADDENDUM www.ti.com 30-Jul-2011 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Drawing Pins Package Qty Eco Plan (2) Lead/ Ball Finish MSL Peak Temp THS4500CD ACTIVE SOIC D 8 75 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4500CDG4 ACTIVE SOIC D 8 75 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4500CDGKR ACTIVE MSOP DGK 8 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4500CDGKRG4 ACTIVE MSOP DGK 8 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4500CDGN ACTIVE MSOPPowerPAD DGN 8 80 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4500CDGNG4 ACTIVE MSOPPowerPAD DGN 8 80 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4500CDGNR ACTIVE MSOPPowerPAD DGN 8 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4500CDGNRG4 ACTIVE MSOPPowerPAD DGN 8 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4500ID ACTIVE SOIC D 8 75 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4500IDG4 ACTIVE SOIC D 8 75 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4500IDGK ACTIVE MSOP DGK 8 80 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4500IDGKG4 ACTIVE MSOP DGK 8 80 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4500IDGN ACTIVE MSOPPowerPAD DGN 8 80 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4500IDGNG4 ACTIVE MSOPPowerPAD DGN 8 80 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4500IDGNR ACTIVE MSOPPowerPAD DGN 8 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4500IDGNRG4 ACTIVE MSOPPowerPAD DGN 8 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4500IDR ACTIVE SOIC D 8 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM www.BDTIC.com/TI Addendum-Page 1 (3) Samples (Requires Login) PACKAGE OPTION ADDENDUM www.ti.com 30-Jul-2011 Orderable Device Status (1) Package Type Package Drawing Pins Package Qty Eco Plan (2) Lead/ Ball Finish MSL Peak Temp THS4500IDRG4 ACTIVE SOIC D 8 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4501CD ACTIVE SOIC D 8 75 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4501CDG4 ACTIVE SOIC D 8 75 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4501CDGN ACTIVE MSOPPowerPAD DGN 8 80 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4501CDGNG4 ACTIVE MSOPPowerPAD DGN 8 80 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4501ID ACTIVE SOIC D 8 75 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4501IDG4 ACTIVE SOIC D 8 75 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4501IDGK ACTIVE MSOP DGK 8 80 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4501IDGKG4 ACTIVE MSOP DGK 8 80 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4501IDGN ACTIVE MSOPPowerPAD DGN 8 80 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4501IDGNG4 ACTIVE MSOPPowerPAD DGN 8 80 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4501IDR ACTIVE SOIC D 8 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM THS4501IDRG4 ACTIVE SOIC D 8 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM (3) Samples (Requires Login) (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability information and additional product content details. TBD: The Pb-Free/Green conversion plan has not been defined. www.BDTIC.com/TI Addendum-Page 2 PACKAGE OPTION ADDENDUM www.ti.com 30-Jul-2011 Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes. Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above. Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material) (3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. 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