* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download VIPower: low cost universal input DVD supply with VIPer22A
Audio power wikipedia , lookup
Electrification wikipedia , lookup
Solar micro-inverter wikipedia , lookup
Spark-gap transmitter wikipedia , lookup
Electrical ballast wikipedia , lookup
Power engineering wikipedia , lookup
Stepper motor wikipedia , lookup
Electrical substation wikipedia , lookup
Power inverter wikipedia , lookup
Current source wikipedia , lookup
Three-phase electric power wikipedia , lookup
Resistive opto-isolator wikipedia , lookup
Variable-frequency drive wikipedia , lookup
History of electric power transmission wikipedia , lookup
Transformer wikipedia , lookup
Pulse-width modulation wikipedia , lookup
Schmitt trigger wikipedia , lookup
Surge protector wikipedia , lookup
Stray voltage wikipedia , lookup
Resonant inductive coupling wikipedia , lookup
Power electronics wikipedia , lookup
Voltage regulator wikipedia , lookup
Alternating current wikipedia , lookup
Voltage optimisation wikipedia , lookup
Mains electricity wikipedia , lookup
Opto-isolator wikipedia , lookup
AN1897 - APPLICATION NOTE ® VIPower: LOW COST UNIVERSAL INPUT DVD SUPPLY WITH VIPer22A Jun-feng Zhang c u d e t le INTRODUCTION ) s t( o r P o s b O - In the past few years, many consumer products have been provided to the end user, such as DVD or VCD players. Generally their power supply require multiple outputs to supply a variety of control circuits: MCU, Motor, Amplifier, VFD. ) s ( ct ST VIPer series of off-line switch mode power supply regulators combines an optimized, high voltage, avalanche rugged Vertical Power MOSFET with current mode control PWM circuitry. The result is truly innovative AC to DC conversion that is simpler, quicker and - with component count halved - less expensive. u d o r P e The VIPer family also represents the easiest solution to comply with the "Blue Angel" and "Energy Star" Eco norms, with extremely low total power consumption at stand-by mode, thanks to the burst operation. t e l o This document would present the application on DVD player power supply with VIPer22A satisfying the specification See table 1 below. s b O Table 1: Output Specification INPUT OUTPUT 1 OUTPUT 2 OUTPUT 3 OUTPUT 4 OUTPUT 5 OUTPUT 6 Universal mains line 5 V +/- 5% +12 V +/- 5% -12 V +/- 5% -26 V +/- 5% (See note 1) (See note 1) (See note 1) (See note 1) 3.3 V +/- 5% (See note 1) 5Vstb +/- 5% Min: 85Vac Max: 265Vac Imin: 20mA Imax: 1.5 A Imax: 150mA Imax: 100mA Imax: 30 mA Imax: 30 mA Imax: 50mA (See note 1) Note 1: The accuracy of +/-5% is reached only for a certain range of loads combination. See paragraph 3.2 for cross regulation results. March 2004 1/11 AN1897 - APPLICATION NOTE 1. APPLICATION DESCRIPTION AND DESIGN 1.1 Schematics The overall schematic is shown in figure 2. 1.1.1 Start-up Phase As any member of the VIPer family, VIPer22A has an integrated high voltage current source linked to Drain pin. At the startup converter, it will charge the V DD capacitor until it reaches VIPer startup level (14.5V), and then the VIPer22A starts switching. 1.1.2 Auxiliary Supply VIPer22A has a wide operating voltage range from 8V to 42V, respectively minimum and maximum values for under-voltage and over-voltage protections. This function is very useful for achieving low stand-by total power consumption. During normal working, the feedback loop is connected to 5V output by D12 to regulate 5V output. At the mean time, +5Vstb output is blocked by Q3, so +5Vstb regulation is neglected. When the stand-by signal is present, the Vce of Q3 can not provide enough voltage to maintain D12 conducted, so the 5V output is blocked, and the +5Vstb output is connected to the feedback loop. In this condition the +5Vstb is regulated. Thanks to the transformer structure, all the other secondary outputs and the auxiliary voltages are pulled down to a very low level, also pulling down the total power consumption. c u d All these contents can be summarized by the following list: e t le ) s t( o r P • in normal full load, the VDD voltage of the device must be lower than the over-voltage protection; o s b O - • in short circuit, the V DD voltage must be lower than the shutdown voltage. Actually, this condition leads to the well known hiccup mode in practice; • in no load condition, the VDD voltage must be higher than the shutdown voltage. ) s ( ct 1.1.3 Burst Mode The Viper22A integrates a current mode PWM with a Power MOSFET and includes the leading edge blanking function. The burst mode is a feature which allows VIPer22A to skip some switching cycles u d o when the energy drained by the output load goes below E=(Tb*Vin)2 * fsw/2Lp (Tb=blanking time, Vin=DC input voltage, f sw=Switching frequency, Lp=Primary Inductance). r P e It has the consequence to reduce the switching losses when working in low load condition by reducing the switching frequency. t e l o s b O 1.1.4 Feedback Loop The 5V output voltage is regulated with a TL-431 (U3) via an optocoupler (U2) to the feedback pin. If the output voltage is high, the TL-431 will draw more current through its cathode to the anode and the current increases in the optocoupler diode. The current in optocoupler NPN increases accordingly and the current into the VIPer22A FB pin increases. When the FB current increases, the VIPer22A will skip some cycles to decrease turn on time and lower the output voltage to the proper level (see figure 1). The 5V output voltage is regulated thanks to the reference voltage of TL-431 and the resistive divider R8 and R9. 2/11 AN1897 - APPLICATION NOTE Figure 1: VIPer22A FB pin internal structure DRAIN 60kHz OSCILLATOR +Vdd S PWM LATCH R Id Q Secondary feedback Is 0.23V IFB 1 kΩ FB R1 C 230 Ω R2 SOURCE c u d ) s t( 1.1.5 Primary Driver In a fly-back power supply, the transformer is used as an energy tank fuelled during the ON time of the MOSFET. When the MOSFET turns off, its drain voltage rises from a low value to the input voltage plus the reflected voltage while the secondary diode conducts, transferring on the secondary side the magnetic energy stored in the transformer. Because primary and secondary windings are not perfectly magnetically coupled, there is a serial leakage inductance that behaves like an open inductor charged at Ipk that causes the voltage spikes on the MOSFET drain. These voltage spikes must be clamped to keep the VIPer22A Drain voltage below the BVdss (730Vmin) rating. If the peak voltage is higher than this value, the device will be destroyed. The most used solution is the RCD clamp (see figure 3). This is a very simple and cheap solution, but it impacts on the efficiency and even on the power dissipation in stand-by condition. Also the clamping voltage varies with load current. RCD clamp circuits may allow the drain voltage to exceed the data sheet breakdown rating of VIPer22A during overload operation or during turn on with high line AC input voltage. So, a zener clamp is recommended (see figure 4). However such a solution gives higher power dissipation at full load, even if the clamp voltage is exactly defined. e t le ) s ( ct o r P o s b O - u d o r P e 1.2 Transformer Consideration On the electrical specification of a multiple output transformer (cross regulation, leakage inductance), the main efforts focused on the proper coupling between the windings. A lower leakage inductance transformer will allow a lower power clamp to reduce the input power. It will lead to lower power dissipation on the primary side. t e l o s b O Auxiliary and secondary windings are swapped in order to decrease the coupling to the primary one. The secondary windings act as a shielding layer to reduce the capacitive coupling. Fewer spikes are generated on the auxiliary windings, the primary and secondary windings have better coupling. Designing transformers for low leakage inductance involves several considerations: •Minimize number of turns •Keep winding build (ratio of winding height to width) small •Increase width of windings •Minimize insulation between windings •Increase coupling between windings 3/11 AN1897 - APPLICATION NOTE Figure 2: Application schematic J3 J5 J4 9 8 7 6 5 4 3 2 1 4 3 2 1 CON4 5 4 3 2 1 CON5 CON9 STB 3.3V Vout 3 +5Vstb / 0.1A F+ (3.3Vac) F- (3.3Vac) / 0.15A C15 100uF/10V GND 2 R9 R8 5.1K 5.1K LD33V U4 Vin 1 +5V / 1.5A --26V / 0.05A --12V / 0.03A +12V / 0.03A R6 1K C10 D12 1N5818 R11 680 ohm U1A 47pF U3 C13 817 C25 TL431 470uF16V 100uF/10V Q3 8550 1K 220uF/50V 220uF/50V BYW 100/200BYW 100/200 1000uF/16V D8 STPS5L60 D9 D7 BYW 100/200 e t le BYW 100/200 9 8 13 10 12 7 11 14 15 o s b O - TX1 TFO EC28---VER3 2 1 D6 1N4937 47pF/1KV FR157 1 2 J2 CON2 Auxiliary Volt 10 Vmin 3.3Vac 0.15A - 26V 0.05A + 12V 0.03A - 12V 0.03A + 5Vstb 0.1A + 5V 1.5A 0.1uF X2 4/11 CON2 1nF / 1KV C3 1 2 250V 1A F1 J1 C8 2 1 C6 47nF 817 2 VIPER22A 1 2.2mH CH1 3 U1B SOURCE C1 2200pF Y1 C2 2200pF Y1 NTC5D-9 RT1 4 VDD 1N4007 D1 1N4007 D2 1N4007 D3 D4 s b O 1N4007 t e l o R3 9.1K CONTROL 100k/1W u d o 47uF/50V U2 R3 C4 C7 DRAIN ) s ( ct D5 JP1 JUMPER C5 o r P 1K C9 C12 D11 r P e 9014 R4 D10 47uF/400V c u d Q1 C20 C19 470uF/25V 470uF/25V C17 D13 1N5818 R5 ) s t( AN1897 - APPLICATION NOTE Figure 3: RCD clamp topology Figure 4: Zener clamp topology ) s t( For a transformer meeting international insulation and safety requirements, a practical value for leakage inductance is about 1-3% of the open circuit primary inductance. c u d A high efficiency transformer should have low inter-winding capacitance to decrease the switching losses. Energy stored in the parasitic capacitance of the transformer is absorbed by VIPer cycle by cycle during the turn-on transition. Excess capacitance will also ring with stray inductance during switch transitions, causing noise problems. Capacitance effects are usually the most important in the primary winding, where the operating voltage (and consequent energy storage) is high. The primary winding should be the first winding on the transformer. This allows the primary winding to have a low mean length per turn, reducing the internal capacitance. The driven end of the primary winding (the end connected to the Drain pin) should be the beginning of the winding rather than the end. e t le o r P o s b O - This takes advantage of the shielding effect of the second half of the primary winding and reduces capacitive coupling to adjacent windings. A layer of insulation between adjacent primary windings can cut the internal capacitance of the primary winding by as much as a factor of four, with consequent reduction of losses. A common technique for winding multiple secondaries with the same polarity sharing a common return, is to stack the secondaries (see figure 5). This arrangement will improve the load regulation, and reduce the total number of secondary turns. ) s ( ct u d o Commonly a clamper based on an RCD network or a diode with a zener to clamp the rise of the drain voltage is used. r P e t e l o Figure 5: Multiple output winding s b O 5/11 AN1897 - APPLICATION NOTE 2. LAYOUT RECOMMENDATION Since EMI issues are strongly related to layout, a basic rule has to be taken into account in high current path routing, i.e. the current loop area has to be minimized. If a heat-sink is used it has to be connected to ground too, in order to reduce common mode emissions, since it is close to the floating drain tab. One more consideration has to be made regarding the control ground connection: in fact in order to avoid any noise interference on VIPer logic pin the control ground has to be separated from power ground. 3. EXPERIMENTAL RESULT 3.1 Efficiency Figure 6: Efficiency at 230Vac (Load on 5V) Figure 7: Efficiency at 260Vac (Load on 5V) +12V/30mA, -12V/30mA, -26V/50mA, 3.3V/0.15A +12V/30mA, -12V/30mA, -26V/50mA, 3.3V/0.15A 80.00% 80.00% 70.00% 70.00% 60.00% Efficiency Efficiency 60.00% 50.00% 40.00% 30.00% 50.00% 40.00% 20.00% 20.00% 10.00% 10.00% 0.1A 0.1A 0.5A 1A 1.5A e t le (s) ct t e l o o r P e 0.1A 0.5A 1.0A 1.5A 2A o s b O - Figure 9: Load Regulation (load on +5V) 5.20 5.15 5.10 Voltage +12V/30mA, -12V/30mA, -26V/50mA, 3.3V/0.15A du 1A Efficiency at 260Vac Input Figure 8: Efficiency at 85Vac (Load on 5V) 76.00% 74.00% 72.00% 70.00% 68.00% 66.00% 64.00% 62.00% 60.00% 0.5A 2A Efficiency at 230Vac Mains Input Efficiency o r P 0.00% 0.00% s b O c u d 30.00% ) s t( 5.05 5.00 4.95 4.90 4.85 4.80 1.5A 2.0A 0A 0.1A 0.5A 1A 1.5A 2A Load (A) Efficiency at 85Vac Input +5V Load Regualtion 3.2 Regulation Table 2: Line regulation 5V/ 0.1A 5Vstb/ 0A 12V/ 0A -12V/ 0A -26V/ 0A 3.3V/ 0A 6/11 Output 85Vac 5.15V 5.15V 12.08V -11.98V -25.82V 3.87V 230Vac 5.15V 5.15V 12.11V -11.99V -25.85V 3.87V 260Vac 5.15V 5.15V 12.12V -12.00V -25.86V 3.88V AN1897 - APPLICATION NOTE Figure 10: Cross regulation +5V/0.5A 15.00 10.00 5.00 Voltage 0.00 0mA -5.00 10mA 30mA 50mA 100mA 150mA -10.00 -15.00 -20.00 -25.00 -30.00 c u d Load (mA) +12V -12V -26V 3.3V e t le Table 3: Stand by model Output 85Vac 5V 2.05V 5Vstb (100mA) ) s ( ct -12V u d o -26V r P e 3.3V Pdis t e l o 230Vac o r P 260Vac 2.05V 2.07V 5.11V 5.14V 4.00V 3.99V 3.98V 3.99V 3.99V 3.98V 9.12V 9.10V 9.08V 1.70V 1.50V 1.51V 0.8W 1W 1.1W 5.08V 12V o s b O - ) s t( Table 4: Full Load Regulation bs 85Vac 230Vac 260Vac 5V/ 1.5A Output 5.02V 5.09V 5.08V 5Vstb/ 0A 5.02V 5.09V 5.08V 12V/30mA 12.03V 12.06V 12.05V -12V/30mA -12.01V -12.05V -12.05V -26V/50mA -26.06V -26.16V -26.15V 3.3V/0.15A 3.77V 3.80V 3.78V VIPer Temp 53°C 47°C 45°C O 7/11 AN1897 - APPLICATION NOTE 4. TRANSFORMER SPECIFICATION Figure 11: Transformer Structure Primary inductance: Lp = 2.8 mH 1KHz, 0.3V Leakage inductance: Lk < 28uH at Secondary and auxiliary winding short (1KHz, 0.3V) Core: EER28L Bobbin: ER28 (6 + 9 Pin) Vendor: YuanDongDa electronics Co., Ltd c u d e t le Table 5: Winding Parameters Layers description Symbol Start Pin Primary Wp Pin2 Out1 (5V/1.5A) W5 Pin7 Out2 (12V/0.03A) W12 Pin11 Out3 (-12V/0.03A) W-12 Out4 (-26V/0.05A) W-26 (s) Wstb r P e o r P Number of Layer Turns b O Pin1 ct u d o Out5 (5Vstb/0.1A) so End Pin ) s t( Wire Size (mm) 2 65 0.3 Pin12 1 4 2*0.6 Pin7 1 5 0.3 Pin12 Pin10 1 9 0.45 Pin10 Pin13 1 10 0.3 Pin9 Pin8 1 12 0.3 Out6 (3.3V/0.15A) W3v3 Pin14 Pin15 1 3 0.3 Auxiliary Waux Pin6 Pin5 1 24 0.3 B O B B I N t e l o 12 7 10 13 15 8 5 Wp W5 W12 W-12 W-26 W3v3 Wstb Waux 7 11 12 14 9 6 s b O 2 Barrier (3mm) 1 10 Barrier (3mm) 8/11 AN1897 - APPLICATION NOTE 5. PCB LAYOUT Figure 12: Bottom view of the demo board (not in scale) c u d e t le Figure 13: PCB Art Work (not in scale) ) s ( ct ) s t( o r P o s b O - u d o r P e t e l o s b O 9/11 AN1897 - APPLICATION NOTE 5. BILL OF MATERIALS Ref. Description Note U1 Photocoupler PC817 SHARP U2 VIPer22A DIP STMicroelectronics U3 TL431 ACZ STMicroelectronics U4 L4931 ABV33 STMicroelectronics Q1 SS9014 Q3 SS8550 D1, D2, D3, D4 1N4007 D5 FR157 D6, D7, D9, D10, D13 STTH102 D8 D11, D12 STMicroelectronics X2 Capacitor 0.1uF C4 Electrolytic Capacitor 100uF/400V C6 Ceramic Capacitor 47nF/50V C7 Electrolytic Capacitor 47uF/50V C9 Electrolytic Capacitor 220uF/50V Ceramic Capacitor 47pF/50V C12 Electrolytic Capacitor 1000uF/16V C13 Electrolytic Capacitor 470uF/16V C15 Electrolytic Capacitor 100uF/10V C17 Electrolytic Capacitor 470uF/25V C19 Electrolytic Capacitor 470uF/25V C20 Electrolytic Capacitor 220uF/50V C25 Electrolytic Capacitor 220uF/16V ) s ( ct r P e t e l o R3 u d o R4, R5, R6 Not fit 9.1KΩ ¼ W 100KΩ 1W 1KΩ ¼ W R8, R9 5.1KΩ ¼ W R11 680Ω ¼ W CH1 2.2mH Common choke TX1 EER28 transformer F1 Fuse 1A J1, J2 2pin connector J3 5pin connector J4 4pin connector J5 9pin connector e t le o s b O - C10 R2 c u d 1nF/1KV RT1 10/11 1N5818 C3 C5, C8 O STMicroelectronics Y1 Capacitor 2200pF C1, C2 bs STMicroelectronics STPS5L60 o r P ) s t( AN1897 - APPLICATION NOTE c u d e t le ) s ( ct ) s t( o r P o s b O - u d o r P e t e l o Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may results from its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics. s b O The ST logo is a trademark of STMicroelectronics. All other names are the property of their respective owners 2004 STMicroelectronics - Printed in ITALY- All Rights Reserved. STMicroelectronics GROUP OF COMPANIES Australia - Belgium - Brazil - Canada - China - Czech Republic - Finland - France - Germany - Hong Kong - India - Israel - Italy - Japan Malaysia - Malta - Morocco - Singapore - Spain - Sweden - Switzerland - United Kingdom - United States http://www.st.com 11/11