Download LT1993-4 - Linear Technology

LT1993-4
900MHz Low Distortion, Low
Noise Differential Amplifier/
ADC Driver (AV = 4V/V)
DESCRIPTIO
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FEATURES
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The LT®1993-4 is a low distortion, low noise Differential
Amplifier/ADC driver for use in applications from DC to
900MHz. The LT1993-4 has been designed for ease of
use, with minimal support circuitry required. Exceptionally low input-referred noise and low distortion products
(with either single-ended or differential inputs) make the
LT1993-4 an excellent solution for driving high speed 12bit and 14-bit ADCs. In addition to the normal unfiltered
outputs (+OUT and –OUT), the LT1993-4 has a built-in
175MHz differential lowpass filter and an additional pair
of filtered outputs (+OUTFILTERED, –OUTFILTERED) to
reduce external filtering components when driving high
speed ADCs. The output common mode voltage is easily set
via the VOCM pin, eliminating either an output transformer
or AC-coupling capacitors in many applications.
900MHz –3dB Bandwidth
Fixed Gain of 4V/V (12dB)
Low Distortion:
40dBm OIP3, –73dBc HD3 (70MHz 2VP-P)
51dBm OIP3, –94dBc HD3 (10MHz 2VP-P)
Low Noise: 14.5dB NF, en = 2.35nV/√Hz (70MHz)
Differential Inputs and Outputs
Additional Filtered Outputs
Adjustable Output Common Mode Voltage
DC- or AC-Coupled Operation
Minimal Support Circuitry Required
Small 0.75mm Tall 16-Lead 3 × 3 QFN Package
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APPLICATIO S
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Differential ADC Driver for:
Imaging
Communications
Differential Driver/Receiver
Single Ended to Differential Conversion
Differential to Single Ended Conversion
Level Shifting
IF Sampling Receivers
SAW Filter Interfacing/Buffering
The LT1993-4 is designed to meet the demanding requirements of communications transceiver applications. It can
be used as a differential ADC driver, a general-purpose
differential gain block, or in any other application requiring differential drive. The LT1993-4 can be used in data
acquisition systems required to function at frequencies
down to DC.
The LT1993-4 operates on a 5V supply and consumes
100mA. It comes in a compact 16-lead 3 × 3 QFN package
and operates over a –40°C to 85°C temperature range.
, LTC and LT are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
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TYPICAL APPLICATIO
4-Tone WCDMA Waveform,
LT1993-4 Driving LTC2255
14-Bit ADC at 92.16Msps
ADC Driver with Single-Ended to Differential Conversion
0
32768 POINT FFT
TONE CENTER FREQUENCIES
AT 62.5MHz, 67.5MHz,
72.5MHz, 77.5MHz
–10
0.1µF
–20
–INB
•
•
–INA
100Ω
MA/COM
ETC1-1-13
0.1µF
–OUTFILTERED
LT1993-4
+OUTFILTERED
+INB
+OUT
+INA
VOCM
ENABLE
2.2V
–30
12.2Ω
–OUT
AIN–
82nH
52.3pF
LTC2255
ADC
AIN+
12.2Ω
12dB GAIN
LTC2255 125Msps
14-BIT ADC SAMPLING
AT 92.16Msps
19934 TA01
AMPLITUDE (dBFS)
70MHz
IF IN
1:1
Z-RATIO
–40
–50
–60
–70
–80
–90
–100
–110
–120
0
5
10
15 20 25 30 35
FREQUENCY (MHz)
40
45
LT19934 TA02
19934fa
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LT1993-4
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W W
W
ABSOLUTE
AXI U RATI GS
U
W
U
PACKAGE/ORDER I FOR ATIO
(Note 1)
–INB
–INA
+INB
+INA
TOP VIEW
16 15 14 13
VCCC 1
12 VEEC
VOCM 2
11 ENABLE
17
VCCA 3
10 VCCB
VEEA 4
6
7
8
+OUT
–OUTFILTERED
–OUT
9
5
+OUTFILTERED
Total Supply Voltage (VCCA/VCCB/VCCC to
VEEA/VEEB/VEEC) ...................................................5.5V
Input Current (+INA, –INA, +INB, –INB,
VOCM, ENABLE)................................................±10mA
Output Current (Continuous) (Note 6)
+OUT, –OUT (DC) ..........................................±100mA
(AC) ..........................................±100mA
+OUTFILTERED, –OUTFILTERED (DC) .............±15mA
(AC) .............±45mA
Output Short Circuit Duration (Note 2) ............ Indefinite
Operating Temperature Range (Note 3) ... –40°C to 85°C
Specified Temperature Range (Note 4) .... –40°C to 85°C
Storage Temperature Range................... –65°C to 125°C
Junction Temperature ........................................... 125°C
Lead Temperature Range (Soldering 10 sec) ........ 300°C
VEEB
UD PACKAGE
16-LEAD (3mm × 3mm) PLASTIC QFN
TJMAX = 125°C, θJA = 68°C/W, θJC = 4.2°C/W
EXPOSED PAD IS VEE (PIN 17)
MUST BE SOLDERED TO THE PCB
UD PART MARKING*
LBNS
LBNS
ORDER PART NUMBER
LT1993CUD-4
LT1993IUD-4
Order Options Tape and Reel: Add #TR
Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF
Lead Free Part Marking: http://www.linear.com/leadfree/
Consult LTC Marketing for parts specified with wider operating temperature ranges.
*The temperature grade is identified by a label on the shipping container.
DC ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VCCA = VCCB = VCCC = 5V, VEEA = VEEB = VEEC = 0V, ENABLE = 0.8V, +INA
shorted to +INB (+IN), –INA shorted to –INB (–IN), VOCM = 2.2V, Input common mode voltage = 2.2V, no RLOAD unless otherwise noted.
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
11.6
11.9
12.4
dB
0.25
0.35
0.5
V
V
Input/Output Characteristics (+INA, +INB, –INA, –INB, +OUT, –OUT, +OUTFILTERED, –OUTFILTERED)
Differential (+OUT, –OUT), VIN = ±0.4V Differential
●
VSWINGMIN
Single-Ended +OUT, –OUT, +OUTFILTERED,
–OUTFILTERED. VIN = ±1.2V Differential
●
VSWINGMAX
Single-Ended +OUT, –OUT, +OUTFILTERED,
–OUTFILTERED. VIN = ±1.2V Differential
3.6
3.5
3.75
●
Differential (+OUT, –OUT), VIN = ±1.2VP-P
Differential
6.5
6
7
●
VP-P
VP-P
(Note 5)
●
±40
±45
mA
–6.5
–10
1
●
GDIFF
Gain
VSWINGDIFF
Output Voltage Swing
IOUT
Output Current Drive
VOS
Input Offset Voltage
TCVOS
Input Offset Voltage Drift
TMIN to TMAX
●
IVRMIN
Input Voltage Range, MIN
Single-Ended
●
Single-Ended
●
4.3
●
77
IVRMAX
Input Voltage Range, MAX
RINDIFF
Differential Input Resistance
CINDIFF
Differential Input Capacitance
V
V
6.5
10
2.5
mV
mV
µV/°C
0.5
V
122
Ω
V
100
1
pF
19934fa
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LT1993-4
DC ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VCCA = VCCB = VCCC = 5V, VEEA = VEEB = VEEC = 0V, ENABLE = 0.8V, +INA
shorted to +INB (+IN), –INA shorted to –INB (–IN), VOCM = 2.2V, Input common mode voltage = 2.2V, no RLOAD unless otherwise noted.
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
CMRR
Common Mode Rejection Ratio
Input Common Mode 0.5V to 4.3V
45
70
dB
ROUTDIFF
Output Resistance
0.3
Ω
COUTDIFF
Output Capacitance
0.8
pF
●
MAX
UNITS
Common Mode Voltage Control (VOCM Pin)
GCM
Common Mode Gain
Differential (+OUT, –OUT), VOCM = 1.2V to 3.6V
Differential (+OUT, –OUT), VOCM = 1.4V to 3.4V
0.9
●
VOCMMIN
Output Common Mode Voltage
Adjustment Range, MIN
Measured Single-Ended at +OUT and –OUT
VOCMMAX
Output Common Mode Voltage
Adjustment Range, MAX
Measured Single-Ended at +OUT and –OUT
VOSCM
Output Common Mode Offset
Voltage
Measured from VOCM to Average of +OUT and –OUT
IBIASCM
VOCM Input Bias Current
●
RINCM
VOCM Input Resistance
●
CINCM
VOCM Input Capacitance
1
0.9
●
●
3.6
3.4
●
–30
0.8
1.1
V/V
1.1
V/V
1.2
1.4
V
V
V
V
2
30
mV
5
15
µA
3
MΩ
1
pF
ENABLE Pin
●
VIL
ENABLE Input Low Voltage
VIH
ENABLE Input High Voltage
IIL
ENABLE Input Low Current
ENABLE = 0.8V
●
IIH
ENABLE Input High Current
ENABLE = 2V
●
●
0.8
V
0.5
µA
3
µA
2
V
1
Power Supply
VS
Operating Range
●
4
5
5.5
V
IS
Supply Current
ENABLE = 0.8V
●
88
100
112
mA
ISDISABLED
Supply Current (Disabled)
ENABLE = 2V
●
250
500
µA
PSRR
Power Supply Rejection Ratio
4V to 5.5V
●
55
90
dB
AC ELECTRICAL CHARACTERISTICS
TA = 25°C, VCCA = VCCB = VCCC = 5V, VEEA = VEEB = VEEC = 0V,
ENABLE = 0.8V, +INA shorted to +INB (+IN), –INA shorted to –INB (–IN), VOCM = 2.2V, Input common mode voltage = 2.2V, no RLOAD
unless otherwise noted.
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
500
900
MHz
Input/Output Characteristics
–3dBBW
–3dB Bandwidth
200mVP-P Differential (+OUT, –OUT)
0.1dBBW
Bandwidth for 0.1dB Flatness
200mVP-P Differential (+OUT, –OUT)
50
MHz
0.5dBBW
Bandwidth for 0.5dB Flatness
200mVP-P Differential (+OUT, –OUT)
100
MHz
SR
Slew Rate
3.2VP-P Differential (+OUT, –OUT)
1100
V/µs
ts1%
1% Settling Time
1% Settling for a 1VP-P Differential Step
(+OUT, –OUT)
tON
tOFF
4
ns
Turn-On Time
40
ns
Turn-Off Time
250
ns
19934fa
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LT1993-4
AC ELECTRICAL CHARACTERISTICS
TA = 25°C, VCCA = VCCB = VCCC = 5V, VEEA = VEEB = VEEC = 0V,
ENABLE = 0.8V, +INA shorted to +INB (+IN), –INA shorted to –INB (–IN), VOCM = 2.2V, Input common mode voltage = 2.2V, no RLOAD
unless otherwise noted.
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Common Mode Voltage Control (VOCM Pin)
–3dBBWCM
SRCM
Common Mode Small-Signal –3dB
Bandwidth
Common Mode Slew Rate
0.1VP-P at VOCM, Measured Single-Ended at +OUT
and –OUT
1.2V to 3.6V Step at VOCM
300
MHz
500
V/µs
Noise/Harmonic Performance Input/output Characteristics
1kHz Signal
Second/Third Harmonic Distortion
Third-Order IMD
2VP-P Differential (+OUTFILTERED, –OUTFILTERED)
–100
dBc
2VP-P Differential (+OUT, –OUT)
–100
dBc
2VP-P Differential (+OUT, –OUT), RL = 100Ω
–100
dBc
3.2VP-P Differential (+OUTFILTERED,
–OUTFILTERED)
3.2VP-P Differential (+OUT, –OUT)
–91
dBc
–91
dBc
3.2VP-P Differential (+OUT, –OUT), RL = 100Ω
–91
dBc
2VP-P Differential Composite (+OUTFILTERED,
–OUTFILTERED), f1 = 0.95kHz, f2 = 1.05kHz
2VP-P Differential Composite (+OUT, –OUT),
RL = 100Ω, f1 = 0.95kHz, f2 = 1.05kHz
3.2VP-P Differential Composite (+OUTFILTERED,
–OUTFILTERED), f1 = 0.95kHz, f2 = 1.05kHz
Differential (+OUTFILTERED, –OUTFILTERED),
f1 = 0.95kHz, f2 = 1.05kHz
–102
dBc
–102
dBc
–93
dBc
54
dBm
OIP31k
Output Third-Order Intercept
en1k
Input Referred Noise Voltage Density
2.15
nV/√Hz
1dB Compression Point
22.7
dBm
10MHz Signal
Second/Third Harmonic Distortion
Third-Order IMD
2VP-P Differential (+OUTFILTERED, –OUTFILTERED)
–94
dBc
2VP-P Differential (+OUT, –OUT)
–94
dBc
2VP-P Differential (+OUT, –OUT), RL = 100Ω
–86
dBc
3.2VP-P Differential (+OUTFILTERED,
–OUTFILTERED)
3.2VP-P Differential (+OUT, –OUT)
–85
dBc
–85
dBc
3.2VP-P Differential (+OUT, –OUT), RL = 100Ω
–77
dBc
2VP-P Differential Composite (+OUTFILTERED,
–OUTFILTERED), f1 = 9.5MHz, f2 = 10.5MHz
2VP-P Differential Composite (+OUT, –OUT),
RL = 100Ω, f1 = 9.5MHz, f2 = 10.5MHz
3.2VP-P Differential Composite (+OUTFILTERED,
–OUTFILTERED), f1 = 9.5MHz, f2 = 10.5MHz
Differential (+OUTFILTERED, –OUTFILTERED),
f1 = 9.5MHz, f2 = 10.5MHz
Measured Using DC800A Demo Board
–96
dBc
–96
dBc
–87
dBc
51
dBm
OIP310M
Output Third-Order Intercept
NF
Noise Figure
13.7
dB
en10M
Input Referred Noise Voltage Density
2.15
nV/√Hz
1dB Compression Point
22.6
dBm
2VP-P Differential (+OUTFILTERED, –OUTFILTERED)
–80
dBc
2VP-P Differential (+OUT, –OUT)
–78
dBc
2VP-P Differential (+OUT, –OUT), RL = 100Ω
–75
dBc
50MHz Signal
Second/Third Harmonic Distortion
19934fa
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LT1993-4
AC ELECTRICAL CHARACTERISTICS
TA = 25°C, VCCA = VCCB = VCCC = 5V, VEEA = VEEB = VEEC = 0V,
ENABLE = 0.8V, +INA shorted to +INB (+IN), –INA shorted to –INB (–IN), VOCM = 2.2V, Input common mode voltage = 2.2V, no RLOAD
unless otherwise noted.
SYMBOL
PARAMETER
Third-Order IMD
OIP350M
Output Third-Order Intercept
NF
Noise Figure
en50M
CONDITIONS
MIN
TYP
MAX
UNITS
3.2VP-P Differential (+OUTFILTERED,
–OUTFILTERED)
3.2VP-P Differential (+OUT, –OUT)
–71
dBc
–69
dBc
3.2VP-P Differential (+OUT, –OUT), RL = 100Ω
–66
dBc
2VP-P Differential Composite (+OUTFILTERED,
–OUTFILTERED), f1 = 49.5MHz, f2 = 50.5MHz
2VP-P Differential Composite (+OUT, –OUT),
RL = 100Ω, f1 = 49.5MHz, f2 = 50.5MHz
3.2VP-P Differential Composite (+OUTFILTERED,
–OUTFILTERED), f1 = 49.5MHz, f2 = 50.5MHz
Differential (+OUTFILTERED, –OUTFILTERED),
f1 = 49.5MHz, f2 = 50.5MHz
Measured Using DC800A Demo Board
–81
dBc
–80
dBc
–72
dBc
43
dBm
14.1
dB
Input Referred Noise Voltage Density
2.25
nV/√Hz
1dB Compression Point
19.7
dBm
70MHz Signal
Second/Third Harmonic Distortion
Third-Order IMD
OIP370M
Output Third-Order Intercept
NF
Noise Figure
en70M
2VP-P Differential (+OUTFILTERED, –OUTFILTERED)
–73
dBc
2VP-P Differential (+OUT, –OUT)
–71
dBc
2VP-P Differential (+OUT, –OUT), RL = 100Ω
–70
dBc
2VP-P Differential Composite (+OUTFILTERED,
–OUTFILTERED), f1 = 69.5MHz, f2 = 70.5MHz
2VP-P Differential Composite (+OUT, –OUT),
RL = 100Ω, f1 = 69.5MHz, f2 = 70.5MHz
Differential (+OUTFILTERED, –OUTFILTERED),
f1 = 69.5MHz, f2 = 70.5MHz
Measured Using DC800A Demo Board
–74
dBc
–71
dBc
40
dBm
14.5
dB
Input Referred Noise Voltage Density
2.35
nV/√Hz
1dB Compression Point
18.5
dBm
100MHz Signal
Second/Third Harmonic Distortion
Third-Order IMD
2VP-P Differential (+OUTFILTERED, –OUTFILTERED)
–61
dBc
2VP-P Differential (+OUT, –OUT)
–63
dBc
2VP-P Differential (+OUT, –OUT), RL = 100Ω
–62
dBc
2VP-P Differential Composite (+OUTFILTERED,
–OUTFILTERED), f1 = 99.5MHz, f2 = 100.5MHz
2VP-P Differential Composite (+OUT, –OUT),
RL = 100Ω, f1 = 99.5MHz, f2 = 100.5MHz
Differential (+OUTFILTERED, –OUTFILTERED),
f1 = 99.5MHz, f2 = 100.5MHz
Measured Using DC800A Demo Board
–61
dBc
–63
dBc
33.5
dBm
15.1
dB
OIP3100M
Output Third-Order Intercept
NF
Noise Figure
en100M
Input Referred Noise Voltage Density
2.55
nV/√Hz
1dB Compression Point
17.8
dBm
Note 1: Absolute Maximum Ratings are those values beyond which the life of a
device may be impaired.
Note 2: As long as output current and junction temperature are kept below the
Absolute Maximum Ratings, no damage to the part will occur.
Note 3: The LT1993C-4 is guaranteed functional over the operating temperature
range of –40°C to 85°C.
Note 4: The LT1993C-4 is guaranteed to meet specified performance from 0°C to
70°C. It is designed, characterized and expected to meet specified performance
from –40°C and 85°C but is not tested or QA sampled at these temperatures. The
LT1993I-4 is guaranteed to meet specified performance from –40°C to 85°C.
Note 5: This parameter is pulse tested.
Note 6: This parameter is guaranteed to meet specified performance through design
and characterization. It has not been tested.
19934fa
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LT1993-4
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Frequency Response
RLOAD = 400Ω
27
18
15
15
10pF
21
1.8pF
15
0pF
12
3
VIN = 50mVP-P
0 UNFILTERED: RLOAD = 400Ω
FILTERED: RLOAD = 350Ω
–3 (EXTERNAL) + 50Ω (INTERNAL
FILTERED OUTPUTS)
–6
1
100
1000
10
FREQUENCY (MHz)
9
GAIN (dB)
18
GAIN (dB)
6
3
VIN = 50mVP-P
0 UNFILTERED: RLOAD = 100Ω
FILTERED: RLOAD = 50Ω
–3 (EXTERNAL) + 50Ω (INTERNAL
FILTERED OUTPUTS)
–6
1
100
1000
10
FREQUENCY (MHz)
6
3
1
10
100
1000
FREQUENCY (MHz)
10000
19934 G02
19934 G01
Third Order Intermodulation
Distortion vs Frequency
Differential Input, RLOAD = 100Ω
–10
–10
2 TONES, 2VP-P COMPOSITE
1MHz TONE SPACING
–10
2 TONES, 2VP-P COMPOSITE
1MHz TONE SPACING
–20
FILTERED
OUTPUTS
–50
–60
UNFILTERED
OUTPUTS
–70
–80
–30
–40
THIRD ORDER IMD (dBc)
THIRD ORDER IMD (dBc)
–40
FILTERED
OUTPUTS
–50
–60
–70
UNFILTERED
OUTPUTS
–80
–50
–60
–70
–90
–90
–100
–100
–110
20
80
60
40
100
FREQUENCY (MHz)
120
–110
0
140
20
80
60
40
100
FREQUENCY (MHz)
120
60
2 TONES, 2VP-P COMPOSITE
1MHz TONE SPACING
60
40
35
30
25
45
UNFILTERED
OUTPUTS
40
35
20
40
80 100
60
FREQUENCY (MHz)
120
140
19334 G07
UNFILTERED
OUTPUTS
40
35
FILTERED
OUTPUTS
25
20
20
0
45
30
FILTERED
OUTPUTS
25
20
140
50
30
FILTERED
OUTPUTS
120
2 TONES, 2VP-P COMPOSITE
1MHz TONE SPACING
55
OUTPUT IP3 (dBm)
OUTPUT IP3 (dBm)
UNFILTERED
OUTPUTS
80
60
40
100
FREQUENCY (MHz)
Output Third Order Intercept vs
Frequency, Differential Input
RLOAD = 100Ω
50
45
20
19934 G06
2 TONES, 2VP-P COMPOSITE
1MHz TONE SPACING
55
50
OUTPUT IP3 (dBm)
0
Output Third Order Intercept vs
Frequency, Differential Input
RLOAD = 400Ω
Output Third Order Intercept vs
Frequency, Differential Input
No RLOAD
55
140
19934 G05
19934 G04
60
UNFILTERED
OUTPUTS
–80
–90
0
FILTERED
OUTPUTS
–40
–100
–110
2 TONES, 2VP-P COMPOSITE
1MHz TONE SPACING
–20
–30
–30
10000
19934 G03
Third Order Intermodulation
Distortion vs Frequency
Differential Input, RLOAD = 400Ω
Third Order Intermodulation
Distortion vs Frequency
Differential Input, No RLOAD
–20
FILTERED
OUTPUTS
6
9
10000
UNFILTERED
OUTPUTS
12
5pF
FILTERED
OUTPUTS
9
GAIN (dB)
18
VIN = 50mVP-P
UNFILTERED OUTPUTS
24
UNFILTERED
OUTPUTS
12
THIRD ORDER IMD (dBc)
Frequency Response
RLOAD = 100Ω
Frequency Response vs CLOAD
RLOAD = 400Ω
0
20
40
80 100
60
FREQUENCY (MHz)
120
140
19334 G08
0
20
40
80 100
60
FREQUENCY (MHz)
120
140
19334 G09
19934fa
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LT1993-4
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Distortion (Unfiltered) vs
Frequency, Differential Input,
No RLOAD
Distortion vs Output Amplitude
70MHz Differential Input
No RLOAD
–10
FILTERED OUTPUTS
–20 VOUT = 2VP-P
–10
UNFILTERED OUTPUTS
–20 VOUT = 2VP-P
–50
–30
–30
–60
–40
–40
HD3
–50
HD2
–60
–70
–80
–55
DISTORTION (dBc)
DISTORTION (dBc)
DISTORTION (dBc)
Distortion (Filtered) vs Frequency
Differential Input, No RLOAD
HD3
–50
–60
HD2
–70
–80
–70
–80
–85
–90
–100
–100
–95
–110
–110
–100
10
100
FREQUENCY (MHz)
10
100
FREQUENCY (MHz)
19934 G10
10
5
15
10
0
5
–5
–10
10
INPUT IMPEDANCE (MAGNITUDE Ω, PHASE°)
–50
ISOLATION (dB)
–60
–70
–80
–90
–100
–110
100
1000
FREQUENCY (MHz)
4
3
2
1
10
10000
19934 G16
100
FREQUENCY (MHz)
1000
19934 G15
Differential Input Impedance vs
Frequency
UNFILTERED OUTPUTS
10
5
''!" /"
Reverse Isolation vs Frequency
1
6
1000
100
FREQUENCY (MHz)
19934 G13
–40
11
0
0
1000
Differential Output Impedance vs
Frequency
100
150
UNFILTERED OUTPUTS
125
100
OUTPUT IMPEDANCE (Ω)
10
100
FREQUENCY (MHz)
1
5
7
9
3
OUTPUT AMPLITUDE (dBm)
19934 G12
INPUT REFERRED NOISE VOLTAGE (nV/√Hz)
15
1
Input Referred Noise Voltage vs
Frequency
VCC = 5V
MEASURED USING
DC800A DEMO BOARD
20
RLOAD = 100Ω
NOISE FIGURE (dB)
OUTPUT 1dB COMPRESSION (dBm)
25
UNFILTERED OUTPUTS
20
–1
Noise Figure vs Frequency
RLOAD = 400Ω
25
1000
19934 G11
Output 1dB Compression vs
Frequency
30
HD2 UNFILTERED
OUTPUTS
HD2 FILTERED
OUTPUTS
–90
1
1000
HD3 FILTERED
OUTPUTS
–75
–90
1
HD3 UNFILTERED
OUTPUTS
–65
IMPEDANCE MAGNITUDE
75
50
25
0
IMPEDANCE PHASE
–25
10
1
–50
–75
0.1
–100
1
10
100
FREQUENCY (MHz)
1000
''!" /%
1
10
100
FREQUENCY (MHz)
1000
''!" /&
19934fa
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LT1993-4
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TYPICAL PERFOR A CE CHARACTERISTICS
Input Reflection Coefficient vs
Frequency
0
–5
–10
–15
–20
–25
–30
–35
–40
–45
–50
MEASURED USING DC800A DEMO BOARD
–5
90
–10
80
–15
70
–20
–25
–30
–35
100
FREQUENCY (MHz)
30
–45
100
FREQUENCY (MHz)
19934 G21
Large-Signal Transient Response
3.0
Overdrive Recovery Time
4.0
RLOAD = 100Ω PER OUTPUT
2.24
2.6
3.0
2.16
2.14
2.12
OUTPUT VOLTAGE (V)
3.5
OUTPUT VOLTAGE (V)
2.8
2.18
2.4
2.2
2.0
5
1.5
1.0
1.6
0.5
5
0
10 15 20 25 30 35 40 45 50
TIME (ns)
''!" / "
Turn-On Time
Turn-Off Time
4
FILTERED OUTPUTS, NO RLOAD
VOUT = 70MHz 2VP-P
4
+OUT
+OUT
3
–66
3
2
2
–OUT
–70
HD3
–72
–OUT
1
0
RLOAD = 100Ω PER OUTPUT
4
2
–76
1.2
VOLTAGE (V)
VOLTAGE (V)
–68
25 50 75 100 125 150 175 200 225 250
TIME (ns)
19934 G23
Distortion vs Output Common
Mode Voltage, LT1993-4 Driving
LTC2249 14-Bit ADC
–74
–OUT
0
0
19934 G22
–64
RLOAD = 100Ω
PER OUTPUT
2.0
1.8
10 15 20 25 30 35 40 45 50
TIME (ns)
+OUT
2.5
1.4
0
1000
19934 G20
RLOAD = 100Ω PER OUTPUT
2.20
10
100
FREQUENCY (MHz)
1
1000
2.26
2.22
PSRR
0
10
Small-Signal Transient Response
DISTORTION (dBc)
40
10
19934 G19
2.28
CMRR
50
20
1000
UNFILTERED OUTPUTS
60
–40
–50
10
OUTPUT VOLTAGE (V)
PSRR, CMRR vs Frequency
100
PSRR, CMRR (dB)
MEASURED USING DC800A DEMO BOARD
OUTPUT REFLECTION COEFFICIENT (S22)
INPUT REFLECTION COEFFICIENT (S11)
0
Output Reflection Coefficient vs
Frequency
1
0
4
ENABLE
2
ENABLE
HD2
1.4 1.6 1.8 2.0 2.2 2.4 2.6
OUTPUT COMMON MODE VOLTAGE (V)
19934 G25
0
0
–2
–2
0
125
250
375
TIME (ns)
500
625
''!" / $
RLOAD = 100Ω PER OUTPUT
0
125
250
375
TIME (ns)
500
625
''!" / %
19934fa
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LT1993-4
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TYPICAL PERFOR A CE CHARACTERISTICS
30MHz 8192 Point FFT, LT1993-4
Driving LTC2249 14-Bit ADC
50MHz 8192 Point FFT, LT1993-4
Driving LTC2249 14-Bit ADC
0
0
0
8192 POINT FFT
fIN = 30MHz, –1dBFS
FILTERED OUTPUTS
–10
–20
8192 POINT FFT
fIN = 50MHz, –1dBFS
FILTERED OUTPUTS
–10
–20
–20
–30
–50
–60
–70
–80
AMPLITUDE (dBFS)
–40
–40
–50
–60
–70
–80
–40
–50
–60
–70
–80
–90
–90
–90
–100
–100
–100
–110
–110
–110
–120
–120
–120
0
5
10
15 20 25 30
FREQUENCY (MHz)
35
40
0
5
10
15 20 25 30
FREQUENCY (MHz)
19934 G28
40
–20
–20
–60
–70
–80
–40
–50
–60
–70
–80
–50
–60
–70
–80
–90
–90
–100
–100
–100
–110
–110
–110
–120
–120
–120
5
10
15 20 25 30
FREQUENCY (MHz)
35
40
40
–40
–90
0
35
–30
AMPLITUDE (dBFS)
–50
15 20 25 30
FREQUENCY (MHz)
32768 POINT FFT
TONE CENTER FREQUENCIES
AT 62.5MHz, 67.5MHz, 72.5MHz, 77.5MHz
–10
–30
–40
10
0
32768 POINT FFT
TONE CENTER FREQUENCIES
AT 67.5MHz, 72.5MHz
–10
AMPLITUDE (dBFS)
–30
5
4-Tone WCDMA Waveform
LT1993-4 Driving LTC2255
14-Bit ADC at 92.16Msps
0
32768 POINT FFT
TONE 1 AT 69.5MHz, –7dBFS
TONE 2 AT 70.5MHz, –7dBFS
FILTERED OUTPUTS
–20
0
19934 G30
2-Tone WCDMA Waveform
LT1993-4 Driving LTC2255
14-Bit ADC at 92.16Msps
0
AMPLITUDE (dBFS)
35
19934 G29
70MHz 2-Tone 32768 Point FFT
LT1993-4 Driving LTC2249
14-Bit ADC
–10
8192 POINT FFT
fIN = 70MHz, –1dBFS
FILTERED OUTPUTS
–10
–30
AMPLITUDE (dBFS)
–30
AMPLITUDE (dBFS)
70MHz 8192 Point FFT, LT1993-4
Driving LTC2249 14-Bit ADC
0
5
10
15 20 25 30 35
FREQUENCY (MHz)
19934 G31
40
45
19934 G32
0
5
10
15 20 25 30 35
FREQUENCY (MHz)
40
45
19934 G33
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PI FU CTIO S
VOCM (Pin 2): This pin sets the output common mode
voltage. Without additional biasing, both inputs bias to
this voltage as well. This input is high impedance.
VCCA, VCCB, VCCC (Pins 3, 10, 1): Positive Power Supply
(Normally Tied to 5V). All three pins must be tied to the
same voltage. Bypass each pin with 1000pF and 0.1µF
capacitors as close to the package as possible. Split
supplies are possible as long as the voltage between VCC
and VEE is 5V.
VEEA, VEEB, VEEC (Pins 4, 9, 12): Negative Power Supply
(Normally Tied to Ground). All three pins must be tied to
the same voltage. Split supplies are possible as long as
the voltage between VCC and VEE is 5V. If these pins are
not tied to ground, bypass each pin with 1000pF and 0.1µF
capacitors as close to the package as possible.
+OUT, –OUT (Pins 5, 8): Outputs (Unfiltered). These
pins are high bandwidth, low-impedance outputs. The DC
output voltage at these pins is set to the voltage applied
at VOCM.
19934fa
9
LT1993-4
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PI FU CTIO S
+OUTFILTERED, –OUTFILTERED (Pins 6, 7): Filtered
Outputs. These pins add a series 25Ω resistor from the
unfiltered outputs and three 12pF capacitors. Each output
has 12pF to VEE, plus an additional 12pF between each pin
(See the Block Diagram). This filter has a –3dB bandwidth
of 175MHz.
–INA, –INB (Pins 14, 13): Negative Inputs. These pins are
normally tied together. These inputs may be DC- or ACcoupled. If the inputs are AC-coupled, they will self-bias
to the voltage applied to the VOCM pin.
+INA, +INB (Pins 16, 15): Positive Inputs. These pins are
normally tied together. These inputs may be DC- or ACcoupled. If the inputs are AC-coupled, they will self-bias
to the voltage applied to the VOCM pin.
ENABLE (Pin 11): This pin is a TTL logic input referenced
to the VEEC pin. If low, the LT1993-4 is enabled and draws
typically 100mA of supply current. If high, the LT1993-4
is disabled and draws typically 250µA.
Exposed Pad (Pin 17): Tie the pad to VEEC (Pin 12). If split
supplies are used, DO NOT tie the pad to ground.
W
BLOCK DIAGRA
200Ω
–INA
100Ω
12pF
–
14
–INB
VEEA
VCCA
+OUT
5
A
100Ω
+OUTFILTERED
+
13
6
25Ω
VEEA
VCCC
200Ω
VOCM
+
2
C
12pF
–
VEEC
200Ω
25Ω
+INA
100Ω
7
+
16
+INB
–OUTFILTERED
VCCB
–OUT
8
B
100Ω
–
15
12pF
VEEB
VEEB
200Ω
BIAS
3
10
VCCA
1
VCCB
11
VCCC
4
ENABLE
9
VEEA
19934 BD
12
VEEB
VEEC
19934fa
10
LT1993-4
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APPLICATIO S I FOR ATIO
Circuit Description
Input Impedance and Matching Networks
The LT1993-4 is a low noise, low distortion differential
amplifier/ADC driver with:
Because of the internal feedback network, calculation of
the LT1993-4’s input impedance is not straightforward
from examination of the block diagram. Furthermore, the
input impedance when driven differentially is different than
when driven single-ended. When driven differentially, the
LT1993-4’s input impedance is 100Ω (differential); when
driven single-ended, the input impedance is 75Ω.
• DC to 900MHz –3dB bandwidth
• Fixed gain of 4V/V (12dB) independent of RLOAD
• 100Ω differential input impedance
• Low output impedance
• Built-in, user adjustable output filtering
• Requires minimal support circuitry
Referring to the block diagram, the LT1993-4 uses a closedloop topology which incorporates 3 internal amplifiers.
Two of the amplifiers (A and B) are identical and drive the
differential outputs. The third amplifier (C) is used to set
the output common mode voltage. Gain and input impedance are set by the 100Ω/200Ω resistors in the internal
feedback network. Output impedance is low, determined
by the inherent output impedance of amplifiers A and B,
and further reduced by internal feedback.
For single-ended 50Ω applications, a 150Ω shunt matching resistor to ground will result in the proper input
termination (Figure 1). For differential inputs there are
several termination options. If the input source is 50Ω
differential, then input matching can be accomplished by
either a 100Ω shunt resistor across the inputs (Figure 3),
or a 49.9Ω shunt resistor on each of the inputs to ground
(Figure 2).
13
14
The LT1993-4 has been designed to minimize the need
for external support components such as transformers or
AC-coupling capacitors. As an ADC driver, the LT1993-4
requires no external components except for power-supply
bypass capacitors. This allows DC-coupled operation for
applications that have frequency ranges including DC.
At the outputs, the common mode voltage is set via the
VOCM pin, allowing the LT1993-4 to drive ADCs directly. No
output AC-coupling capacitors or transformers are needed.
At the inputs, signals can be differential or single-ended
with virtually no difference in performance. Furthermore,
DC levels at the inputs can be set independently of the
output common mode voltage. These input characteristics
often eliminate the need for an input transformer and/or
AC-coupling capacitors.
–OUT
–INA
8
LT1993-4
IF IN
The LT1993-4 also includes built-in single-pole output
filtering. The user has the choice of using the unfiltered
outputs, the filtered outputs (175MHz –3dB lowpass), or
modifying the filtered outputs to alter frequency response
by adding additional components. Many lowpass and
bandpass filters are easily implemented with just one or
two additional components.
–INB
15
16
+INB
+OUT
+INA
5
19934 F01
Figure 1. Input Termination for Single-Ended 50Ω
Input Impedance
13
IF IN–
14
–INB
–INA
–OUT
8
LT1993-4
15
IF IN+
16
+INB
+OUT
+INA
5
19934 F02
Figure 2. Input Termination for Differential 50Ω Input Impedance
13
IF IN–
14
–INB
–INA
–OUT
8
LT1993-4
15
IF IN+
16
+INB
+INA
+OUT
5
19934 F03
Figure 3. Alternate Input Termination for Differential
50Ω Input Impedance
19934fa
11
LT1993-4
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APPLICATIO S I FOR ATIO
Single-Ended to Differential Operation
The LT1993-4’s performance with single-ended inputs is
comparable to its performance with differential inputs.
This excellent single-ended performance is largely due
to the internal topology of the LT1993-4. Referring to
the block diagram, if the +INA and +INB pins are driven
with a single-ended signal (while –INA and –INB are tied
to AC ground), then the +OUT and –OUT pins are driven
differentially without any voltage swing needed from
amplifier C. Single-ended to differential conversion using
more conventional topologies suffers from performance
limitations due to the common mode amplifier.
Driving ADCs
The LT1993-4 has been specifically designed to interface
directly with high speed Analog to Digital Converters
(ADCs). In general, these ADCs have differential inputs,
with an input impedance of 1k or higher. In addition, there
is generally some form of lowpass or bandpass filtering just
prior to the ADC to limit input noise at the ADC, thereby
improving system signal to noise ratio. Both the unfiltered
and filtered outputs of the LT1993-4 can easily drive the
high impedance inputs of these differential ADCs. If the
filtered outputs are used, then cutoff frequency and the
type of filter can be tailored for the specific application if
needed.
Wideband Applications
(Using the +OUT and –OUT Pins)
In applications where the full bandwidth of the LT1993-4
is desired, the unfiltered output pins (+OUT and –OUT)
should be used. They have a low output impedance;
therefore, gain is unaffected by output load. Capacitance
in excess of 5pF placed directly on the unfiltered outputs
results in additional peaking and reduced performance.
When driving an ADC directly, a small series resistance
is recommended between the LT1993-4’s outputs and
the ADC inputs (Figure 4). This resistance helps eliminate
any resonances associated with bond wire inductances of
either the ADC inputs or the LT1993-4’s outputs. A value
between 10Ω and 25Ω gives excellent results.
–OUT
10Ω TO 25Ω
8
LT1993-4
ADC
10Ω TO 25Ω
+OUT
5
19934 F04
Figure 4. Adding Small Series R at LT1993-4 Output
Filtered Applications
(Using the +OUTFILTERED and –OUTFILTERED Pins)
Filtering at the output of the LT1993-4 is often desired to
provide either anti-aliasing or improved signal to noise
ratio. To simplify this filtering, the LT1993-4 includes an
additional pair of differential outputs (+OUTFILTERED and
–OUTFILTERED) which incorporate an internal lowpass
filter network with a –3dB bandwidth of 175MHz (Figure
5). These pins each have an output impedance of 25Ω. Internal capacitances are 12pF to VEE on each filtered output,
plus an additional 12pF capacitor connected differentially
between the two filtered outputs. This resistor/capacitor combination creates filtered outputs that look like a
series 25Ω resistor with a 36pF capacitor shunting each
filtered output to AC ground, giving a –3dB bandwidth of
175MHz.
LT1993-4
VEE
259
8 –OUT
12pF
7 –OUTFILTERED
FILTERED OUTPUT
(175MHz)
12pF
259
6 +OUTFILTERED
12pF
VEE
5 +OUT
19934 F05
Figure 5. LT1993-4 Internal Filter Topology –3dB BW ≈175MHz
The filter cutoff frequency is easily modified with just a
few external components. To increase the cutoff frequency,
simply add 2 equal value resistors, one between +OUT and
+OUTFILTERED and the other between –OUT and –OUTFILTERED (Figure 6). These resistors are in parallel with the
internal 25Ω resistor, lowering the overall resistance and
increasing filter bandwidth. To double the filter bandwidth,
for example, add two external 25Ω resistors to lower
the series resistance to 12.5Ω. The 36pF of capacitance
remains unchanged, so filter bandwidth doubles.
19934fa
12
LT1993-4
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APPLICATIO S I FOR ATIO
LT1993-4
LT1993-4
8 –OUT
VEE
VEE
25Ω
259
12pF
12pF
7 –OUTFILTERED
7 –OUTFILTERED
FILTERED OUTPUT
(350MHz)
12pF
25Ω
6 +OUTFILTERED
VEE
Figure 6. LT1993-4 Internal Filter Topology Modified for
2x Filter Bandwidth (2 External Resistors)
To decrease filter bandwidth, add two external capacitors, one from +OUTFILTERED to ground, and the other
from –OUTFILTERED to ground. A single differential
capacitor connected between +OUTFILTERED and –OUTFILTERED can also be used, but since it is being driven
differentially it will appear at each filtered output as a
single-ended capacitance of twice the value. To halve the
filter bandwidth, for example, two 36pF capacitors could
be added (one from each filtered output to ground). Alternatively one 18pF capacitor could be added between
the filtered outputs, again halving the filter bandwidth.
Combinations of capacitors could be used as well; a three
capacitor solution of 12pF from each filtered output to
ground plus a 12pF capacitor between the filtered outputs
would also halve the filter bandwidth (Figure 7).
259
8 –OUT
12pF
7 –OUTFILTERED
12pF
259
12pF
12pF
6 +OUTFILTERED
FILTERED OUTPUT
(87.5MHz)
12pF
12pF
VEE
FILTERED OUTPUT
120pF (71MHz BANDPASS,
–3dB @ 55MHz/87MHz)
6 +OUTFILTERED
VEE
19934 F06
VEE
39nH
12pF
5 +OUT
LT1993-4
12pF
259
12pF
8 –OUT
5 +OUT
19934 F07
Figure 7. LT1993-4 Internal Filter Topology Modified for
1/2x Filter Bandwidth (3 External Capacitors)
Bandpass filtering is also easily implemented with just a
few external components. An additional 120pF and 39nH,
each added differentially between +OUTFILTERED and
–OUTFILTERED creates a bandpass filter with a 71MHz
center frequency, –3dB points of 55MHz and 87MHz, and
1.6dB of insertion loss (Figure 8).
5 +OUT
19934 F08
Figure 8. LT1993-4 Output Filter Topology Modified for Bandpass
Filtering (1 External Inductor, 1 External Capacitor)
Output Common Mode Adjustment
The LT1993-4’s output common mode voltage is set by the
VOCM pin. It is a high-impedance input, capable of setting
the output common mode voltage anywhere in a range
from 1.1V to 3.6V. Bandwidth of the VOCM pin is typically
300MHz, so for applications where the VOCM pin is tied to
a DC bias voltage, a 0.1µF capacitor at this pin is recommended. For best distortion performance, the voltage at
the VOCM pin should be between 1.8V and 2.6V.
When interfacing with most ADCs, there is generally a VOCM
output pin that is at about half of the supply voltage of the
ADC. For 5V ADCs such as the LTC17XX family, this VOCM
output pin should be connected directly (with the addition
of a 0.1µF capacitor) to the input VOCM pin of the LT1993-4.
For 3V ADCs such as the LTC22XX families, the LT19934 will function properly using the 1.65V from the ADC’s
VCM reference pin, but improved Spurious Free Dynamic
Range (SFDR) and distortion performance can be achieved
by level-shifting the LTC22XX’s VCM reference voltage up
to at least 1.8V. This can be accomplished as shown in
Figure 9 by using a resistor divider between the LTC22XX’s
VCM output pin and VCC and then bypassing the LT1993-4’s
VOCM pin with a 0.1µF capacitor. For a common mode voltage above 1.9V, AC coupling capacitors are recommended
between the LT1993-4 and the LTC22XX ADC because of
the input voltage range constraints of the ADC.
19934fa
13
LT1993-4
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APPLICATIO S I FOR ATIO
input bias current is determined by the voltage difference
between the input common mode voltage and the VOCM pin
(which sets the output common mode voltage). At both
the positive and negative inputs, any voltage difference is
imposed across 100Ω, generating an input bias current.
For example, if the inputs are tied to 2.5V with the VOCM
pin at 2.2V, then a total input bias current of 3mA will flow
into the LT1993-4’s +INA and +INB pins. Furthermore, an
additional input bias current totaling 3mA will flow into
the –INA and –INB inputs.
3V
11k
1.9V
4.02k
13
14
2
–INB
VOCM
–INA
+OUTFILTERED
31 1.5V
6
1
7
2
VCM
AIN+
LT1993-4
15
IF IN
16
–OUTFILTERED
+INB
LTC22xx
AIN–
+INA
19934 F09
Figure 9. Level Shifting 3V ADC VCM Voltage for
Improved SFDR
Application (Demo) Boards
Large Output Voltage Swings
The LT1993-4 has been designed to provide the 3.2VP-P
output swing needed by the LTC1748 family of 14-bit
low-noise ADCs. This additional output swing improves
system SNR by up to 4dB. Typical performance curves
and AC specifications have been included for these
applications.
Input Bias Voltage and Bias Current
The input pins of the LT1993-4 are internally biased to
the voltage applied to the VOCM pin. No external biasing
resistors are needed, even for AC-coupled operation. The
The DC800A Demo Board has been created for stand-alone
evaluation of the LT1993-4 with either single-ended or
differential input and output signals. As shown, it accepts
a single-ended input and produces a single-ended output
so that the LT1993-4 can be evaluated using standard
laboratory test equipment. For more information on this
Demo Board, please refer to the Demo Board section of
this datasheet.
There are also additional demo boards available that
combine the LT1993-4 with a variety of different Linear
Technology ADCs. Please contact the factory for more
information on these demo boards.
U
PACKAGE DESCRIPTIO
UD Package
16-Lead Plastic QFN (3mm × 3mm)
(Reference LTC DWG # 05-08-1691)
BOTTOM VIEW—EXPOSED PAD
3.00 ± 0.10
(4 SIDES)
0.70 ±0.05
15
PIN 1
TOP MARK
(NOTE 6)
0.40 ± 0.10
PACKAGE
OUTLINE
0.25 ±0.05
0.50 BSC
16
1
1.45 ± 0.10
(4-SIDES)
3.50 ± 0.05
1.45 ± 0.05
2.10 ± 0.05 (4 SIDES)
PIN 1 NOTCH R = 0.20 TYP
OR 0.25 × 45° CHAMFER
R = 0.115
TYP
0.75 ± 0.05
2
(UD16) QFN 0904
0.200 REF
0.00 – 0.05
0.25 ± 0.05
0.50 BSC
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
NOTE:
1. DRAWING CONFORMS TO JEDEC PACKAGE OUTLINE MO-220 VARIATION (WEED-2)
2. DRAWING NOT TO SCALE
3. ALL DIMENSIONS ARE IN MILLIMETERS
4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE
MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE
5. EXPOSED PAD SHALL BE SOLDER PLATED
6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION
ON THE TOP AND BOTTOM OF PACKAGE
19934fa
14
LT1993-4
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19934fa
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
15
LT1993-4
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TYPICAL APPLICATIO
Demo Circuit DC800A Schematic
(AC Test Circuit)
R18
0W
R17
0W
GND
1
SW1
TP1
ENABLE
VCC
VCC
VCC
3
2
R16
0W
2
C17
1000pF
1
2
1
C18
0.01mF
1
1
J1
–IN
T1
5 1:1 Z-RATIO
MA/COM
ETC1-1-13
14
2
3
R5
0W
16
2
R3
50W
9
VCCB VEEB
–INB
–OUT
–INA
2
1
+INB
6
+OUTFILTERED
+INA
VCCC
VOCM
VCCA
+OUT
VEEA
2
3
4
2
C12
1000pF
C9 2
1000pF
1
1
C4
0.1mF
R10
8 24.9W
7
–OUTFILTERED
1
VCC
C10
0.01mF
10
ENABLE
LT1993-4
15
C11
0.1mF
VCC
11
VEEC
0dB
2
1
R1
[1]
13
C21
0.1mF
1
•
•
0dB
J2
+IN
R6
0W
2
1
4
12
C2
0.1mF
1
R8
[1]
R7
[1]
R9
5 24.9W
L1
[1]
1
C11
[1]
2
R14
0W
R12
75W
2
J4
–OUT
T2
3 4:1 Z-RATIO 4
2
C8
[1]
1
R15
[1]
+10.8dB
1
2
+6dB
1
C3
0.1mF
R11
75W
5
MINI0dB
CIRCUITS
TCM 4-19
J5
+OUT
2
1
VCC
2
1
•
R4
50W
•
R2
0W
2
C16
[1]
2
1
C22
0.1mF
R13
[1]
C13
0.01mF
R19
14k
J3
2
J6
TEST IN
T3
1:4
5
1
•
•
2
C19 0.1mF
1
4
TP2
VCC
1
2
1
2
1
C15
1mF
C5
0.1mF
1
R21
[1]
2
C6
0.1mF
2
R22
[1]
C20 0.1mF
1
2
1
2
T4
4:1
3
4
J7
TEST OUT
2
1
3
MINICIRCUITS
TCM 4-19
VCC
C14
4.7mF
C7
0.01mF
1
•
R20
11k
•
VOCM
5
MINICIRCUITS
TCM 4-19
NOTES: UNLESS OTHERWISE SPECIFIED,
[1] DO NOT STUFF.
TP3
GND
1
19934 TA03
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PART NUMBER
DESCRIPTION
COMMENTS
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LT6600-5
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LT6600-10
Very Low Noise Differential Amplifier and 10MHz Lowpass Filter
82dB S/N with 3V Supply, SO-8 Package
LT6600-20
Very Low Noise Differential Amplifier and 20MHz Lowpass Filter
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19934fa
16 Linear Technology Corporation
LT/LT 1005 REV A • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear.com
© LINEAR TECHNOLOGY CORPORATION 2005