DER-97 115VAC 230VAC CISPR22B EN55022B IEC950 UL1950 TL431 5GAD47 440LD22

Title 21.7 W Power Supply using TOP246P Specification Input: 85 - 265 VAC Output: 48 V / 450 mA Application PoE AC Adapter Author

Design Example Report Title 21.7 W Power Supply using TOP246P Specification Input: 85 - 265 VAC Output: 48 V / 450 mA Application PoE AC Adapter Author Power Integrations Applications Department Document Number DER-97 DER-97 Date September 12, 2005 Revision 1.0 Summary and Features · · · · · · · · · Single Sided PC board Reduced cost and component count Eliminates two y-capacitors to ground Eliminates secondary side common mode choke Eliminates ground wire differential choke High Efficiency (~ 80 %) Lower Cost Transformer Construction no sleeving termination required Low EMI signature (both radiated and conducted emissions) Built-in output short circuit protection The products and applications illustrated herein (including circuits external to the products and transformer construction) may be covered by one or more U.S. and foreign patents or potentially by pending U.S. and foreign patent applications assigned to Power Integrations. A complete list of Power Integrations' patents may be found at www.powerint.com. Power Integrations 5245 Hellyer Avenue, San Jose, CA 95138 USA. Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com DER-97 DER-97 21.7 W PoE Adapter September 12, 2005 Table Of Contents 1 2 3 4 Introduction. 3 Power Supply Specification . 4 Schematic. 5 Circuit Operation . 6 4.1 General . 6 4.2 Description . 6 5 Bill of Materials . 7 6 Layout. 9 7 Transformer Design Spreadsheet . 10 8 Transformer Specification. 13 9 Performance. 17 9.1 Efficiency. 17 9.2 Regulation vs. Load. 18 9.3 Regulation vs. Line. 19 9.4 Raw Performance Data . 20 10 Waveforms. 21 10.1 Drain Current and Voltage. 21 10.2 Output Transient Load Response . 22 10.3 Output Ripple Voltage . 23 10.4 Switching Ripple. 23 10.5 Line Frequency Ripple . 24 10.6 Output Voltage Shutdown Profile . 26 11 Thermal Test. 27 11.1 Thermal Performance. 27 12 Conducted EMI . 29 12.1 Conducted EMI Performance . 29 13 Revision History. 30 Important Notes: Although this board is designed to satisfy safety isolation requirements, the engineering prototype has not been agency approved. Therefore, all testing should be performed using an isolated source to provide power to the prototype board. Design Reports contain a power supply design specification, schematic, bill of materials, and transformer documentation. Performance data and typical operation characteristics are included. Typically only a single prototype has been built. Page 2 of 31 Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com DER-97 DER-97 21.7 W PoE Adapter September 12, 2005 1 Introduction This document is an engineering report describing a Power over Ethernet (PoE) power supply utilizing TOP246P. The power supply delivers 21.7 W continuous from an input of 85 to 265 VAC. This document provides complete design information including specification, schematic, bill of material and transformer design and construction information. The document also provides performance information. Figure 1 Circuit Board - Top View Figure 2 Circuit Board - Bottom View Page 3 of 31 Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com DER-97 DER-97 21.7 W PoE Adapter September 12, 2005 2 Power Supply Specification Description Symbol Min VIN 85 VOUT1 VRIPPLE1 IOUT1 47.52 115 VAC TH(115VAC 115VAC) 18 ms 230 VAC TH(230VAC 230VAC) 60 ms Input Voltage Output Output Voltage 1 Output Ripple Voltage 1 Output Current 1 Power Down Holdup Total Output Power Average Output Power Full Load Efficiency Typ 0 Units 265 48 Max VAC 48.48 480 450 V mVp-p mA POUT1 21.7 80 ± 1% 20 MHz bandwidth W Comment % Environmental Conducted EMI Meets CISPR22B CISPR22B / EN55022B EN55022B Designed to meet IEC950 IEC950, UL1950 UL1950 Class II Safety Ambient Temperature Page 4 of 31 TAMB 0 40 o C Forced airflow Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com DER-97 DER-97 3 21.7 W PoE Adapter September 12, 2005 Schematic Figure 3 Schematic Page 5 of 31 Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com DER-97 DER-97 21.7 W PoE Adapter September 12, 2005 4 Circuit Operation 4.1 General The power supply uses a TOP246P device (U2), with integrated MOSFET and controller, in an isolated flyback configuration. The circuit also uses the x-pin programmable current limit feature control the overload power of the power supply and also to minimize transformer size. 4.2 Description The input fuse F1 protects the supply against catastrophic failure. Thermistor RT1 limits the in-rush current during power-up. Diodes D5 D8 implement a bridge rectifier to rectify the input mains voltage. Capacitor C22 attenuates the EMI generated by the input bridge diodes D5-D8. Inductor L1 is used to attenuate both differential and common mode EMI noise from the power supply. A large value is used to also prevent any noise filtering through from networks connector to the power supply output. Capacitor C2 forms part of the EMI solution by shunting EMI signals generated across the transformer T2. Capacitor C4 decouples the rectified input voltage providing a DC-bus. Resistor R14 programs the current limit of the TOPSwitch-GX (U2). Resistors R6 and R9 modified this current limit with input voltage, to maintain a relatively flat output overload profile. Diode D2, R2, C1 and R1 implement an RCD clamp circuit to limit the leakage inductance spike on the TOPSwitch-GX Drain pin. Diode D3 and C8 implement a bias voltage supply to provide operating power to the TOPSwitch-GX with integrated PWM, controller and main switching MOSFET. Capacitors C13 and C14 provide device decoupling with C14 also programming the startup and auto-restart period of the device. Resistor R13 provides feedback compensation in conjunction with C14. The inductance of transformer T2 provides the energy storage and conversion component of the circuit. Resistor R41 feeds current to an indicator LED U6, which is illuminated during normal operation. The 48 V output is rectified and filtered by diodes D1 and D4 and capacitors C5 with C7 provided output decoupling. Resistor R18 and C21 snub high frequency ringing on these diodes. Resistors R8 and R15 sense the output voltage providing the input signal for the TL431 TL431 (U3) reference. Resistor R41 provides DC bias current (approx. 1 mA) to the U3. Components R12 and C12 provide compensation for U3, to make sure that it's frequency response is limited only to low-frequency signals. Resistor R10 programs the highfrequency gain of the control loop and with opto-diode U5A transmits the feedback signal. Resistor R42 and C15 provide increase the high frequency gain of the feedback circuit to improve output ripple rejection. Zener diode VR1 is used due to the high 48 V output voltage and drops approximately 30 V, to bring the TL431 TL431 collector voltage comfortably within safe levels (i.e. less than 30 V). Opto-transistor U5B feeds the control signal back to the TOPSwitch-GX. Page 6 of 31 Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com DER-97 DER-97 21.7 W PoE Adapter September 12, 2005 5 Bill of Materials Item Qty. Ref. Description Mfg Part Number Mfg 1 1 C1 4.7 nF, 1 kV, Thru Hole, Disc Ceramic 5GAD47 5GAD47 Vishay/Sprague 2 1 C2 3 1 C4 440LD22 440LD22 Vishay KMX400VB47RM16X KMX400VB47RM16X 25LL United Chemi-Con 4 1 C5 5 1 C7 6 1 C8 2.2 nF, Ceramic, Y1 47 uF, 400 V, Electrolytic, Low ESR, 730 mOhm, (16 x 25) 180 uF, 63, Electrolytic, Low ESR, 145 mOhm, (10 x 20) 68 uF, 63, Electrolytic, Low ESR, 340 mOhm, (8 x 12) 10 uF, 50 V, Electrolytic, Gen. Purpose, (5 x 11) 7 2 C12 C15 1.0 uF, 50 V, Ceramic, Z5U ECU-S1H105MEB ECU-S1H105MEB Panasonic 8 1 C13 ECU-S1H104KBB ECU-S1H104KBB Panasonic 9 1 C14 100 nF, 50 V, Ceramic, X7R 47 uF, 16 V, Electrolytic, Low ESR, 500 mOhm, (5 x 11.5) 10 1 C21 100 pF, 1 kV, Disc Ceramic LXZ16VB47RME11LL LXZ16VB47RME11LL United Chemi-Con NIC Components NCD101K1KVY5F NCD101K1KVY5F Corp 11 1 C22 47 nF, 275 VAC, Film, X2 ECQU2A473ML ECQU2A473ML 12 2 D1 D4 13 1 D2 100 V, 1 A, Schottky, DO-41 DO-41 SB1100 SB1100 1000 V, 1 A, Rectifier, Glass Passivated, 2 us, DO-41 DO-41 1N4007GP 1N4007GP 14 1 D3 15 LXZ63VB181MJ20LL LXZ63VB181MJ20LL United Chemi-Con LXZ63VB68RMH15LL LXZ63VB68RMH15LL United Chemi-Con KME50VB10RM5X11 KME50VB10RM5X11 LL United Chemi-Con Panasonic Fairchild Vishay Vishay 2 D5 D6 75 V, 300 mA, Fast Switching, DO-35 DO-35 1N4148 1N4148 600 V, 1 A, Ultrafast Recovery, 75 ns, DO41 UF4005 UF4005 16 2 D7 D8 600 V, 1 A, Rectifier, DO-41 DO-41 1N4005 1N4005 Vishay 17 1 F1 3,721,100,041 Wickman 18 1 J4 1 A, 250V, Slow, TR5 AC Input Receptacle and Accessory Plug, PCBM 161-R301SN13 161-R301SN13 Kobiconn 19 2 J5 J6 R/A, RJ45 Nonshielded, PCBM RJHS-5080 RJHS-5080 Amphenol Canada 20 1 L1 19 mH, 0.5 A, Common Mode Choke ELF15N005A ELF15N005A Panasonic 21 1 L2 3.3 uH, 2.66 A 822LY-3R3M 822LY-3R3M Toko 22 1 R1 100 k, 5%, 1 W, Metal Oxide RSF100JB-100K RSF100JB-100K Yageo 23 1 R2 47 R, 5%, 1/2 W, Carbon Film CFR-50JB-47R CFR-50JB-47R Yageo 24 1 R6 3 M, 5%, 1/8 W, Carbon Film CFR-12JB-3M0 CFR-12JB-3M0 Yageo 25 1 R8 182 k, 1%, 1/4 W, Metal Film MFR-25FBF-182K MFR-25FBF-182K Yageo 26 1 R9 2.7 M, 5%, 1/8 W, Carbon Film CFR-12JB-2M7 CFR-12JB-2M7 Yageo 27 1 R10 3.3 k, 5%, 1/8 W, Carbon Film CFR-12JB-3K3 CFR-12JB-3K3 Yageo 28 2 R12 R40 1 k, 5%, 1/8 W, Carbon Film CFR-12JB-1K0 CFR-12JB-1K0 Yageo 29 1 R13 6.8 R, 5%, 1/8 W, Carbon Film CFR-12JB-6R8 CFR-12JB-6R8 Yageo Page 7 of 31 Vishay Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com DER-97 DER-97 21.7 W PoE Adapter September 12, 2005 30 1 R14 9.09 k, 1%, 1/4 W, Metal Film MFR-25FBF-9K09 MFR-25FBF-9K09 Yageo 31 1 R15 10 k, 1%, 1/4 W, Metal Film MFR-25FBF-10K0 MFR-25FBF-10K0 Yageo 32 1 R18 10 R, 5%, 1/4 W, Carbon Film CFR-25JB-10R CFR-25JB-10R Yageo 33 1 R41 2 k, 5%, 1/8 W, Carbon Film CFR-12JB-2K0 CFR-12JB-2K0 Yageo 34 1 R42 330 R, 5%, 1/8 W, Carbon Film CFR-12JB-330R CFR-12JB-330R Yageo 35 1 RT1 NTC Thermistor, 30 Ohms, 1.5 A CL210 CL210 36 1 T2 Bobbin, EEL25 EEL25.4, Horizontal, 10 pins YW-236-03B YW-236-03B Thermometrics Yih-Hwa Enterprises 37 1 U2 38 1 U3 TOPSwitch-GX, TOP246P, DIP-8B TOP246P 2.495 V Shunt Regulator IC, 2%, 0 to 70C, TO-92 TL431CLP TL431CLP Texas Instruments 39 1 U5 Opto coupler, 35 V, CTR 300-600%, 4-DIP ISP817D ISP817D, PC817X4 PC817X4 Isocom, Sharp 40 1 U6 LED, Green, 5 mm, 565 nm, 30 mcd SSL-LX5093GD SSL-LX5093GD Lumex Opto 41 1 VR1 30 V, 5%, 500 mW, DO-35 DO-35 1N5256B 1N5256B Microsemi Power Integrations 47 Total Page 8 of 31 Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com DER-97 DER-97 21.7 W PoE Adapter September 12, 2005 6 Layout Figure 4 PC Board Layout Page 9 of 31 Power Integrations Tel: +1 408 414 9200 Fax: +1 408 414 9201 www.powerint.com DER-97 DER-97 21.7 W PoE Adapter September 12, 2005 7 Transformer Design Spreadsheet ACDC_TOPSwitchGX_020 INPUT 105; Rev.2.5; Copyright Power Integrations 2005 ENTER APPLICATION VARIABLES VACMIN 85 VACMAX 265 fL 50 VO 48 PO 21.7 n 0.86 Z 0.44 VB 12 tC 2.66 CIN 47 ENTER TOPSWITCH-GX VARIABLES TOP-GX top246p Chosen Device KI INFO UNIT Volts Volts Hertz Volts Watts TOP_GX_FX_020105.xls: TOPSwitch-GX/FX Continuous/Discontinuous Flyback Transformer Design Spreadsheet Customer Volts mSeconds uFarads TOP246P Power Out Maximum AC Input Voltage AC Mains Frequency Output Voltage (main) Output Power Efficiency Estimate Loss Allocation Factor Bias Voltage Bridge Rectifier Conduction Time Estimate Input Filter Capacitor Universal 26W 115 Doubled/230V 34W 0.78 ILIMITMIN ILIMITMAX Frequency (F)=132kHz, (H)=66kHz fS OUTPUT External Ilimit reduction factor (KI=1.0 for default ILIMIT, KI