STEVAL-ISA204V1 Data brief 100W 5V/20A active clamp forward converter based on PM8804 for telecom systems Features * * DC-DC forward converter based on PM8804 Input voltage range: 42 - 56 VDC * * Switching frequency: 250 kHz Output: - Power: 100 W - Voltage: 5 VDC * * * * - Current: up to 20 A Peak efficiency > 94% Open circuit protection RoHS complaint WEEE compliant Description The STEVAL-ISA204V1 evaluation board is designed to demonstrate high efficiency DC-DC conversion, able to output 100 W (5 V/20 A) from 42 to 56 V DC input, which is especially suitable for telecom applications. Product summary 100W 5V/20A forward STEVALconverter based on ISA204V1 PM8804 PWM controller PWM peak current mode controller for PoE and telecom systems PM8804 Application Server & Telecom Power The power conversion stage is based on an active clamp forward topology managed by a PM8804 PWM controller featuring all the integrated circuitry necessary for a compact and efficient 48 V converter. The highly configurable controller includes a programmable oscillator for switching frequency regulation up to 1 Mhz, adjustable slope compensation, dual complementary low-side drivers with programmable dead time, programmable soft start, soft turn off and a programmable current sense blanking time. DB3958 - Rev 1 - June 2019 For further information contact your local STMicroelectronics sales office. www.st.com STEVAL-ISA204V1 Application overview 1 Application overview The STEVAL-ISA204V1 represents a forward converter application with synchronous rectification for 48 V auxiliary power supplies destined for server and telecommunications equipment. The board can supply an output current up to 20 A. The PM8804 integrates two MOSFET drivers with up to 1 A peak sink current capability. The GAT1 signal drives the main switching MOSFET, while the GAT2 signal controls a P-channel MOSFET referred to PGND in active clamp forward topology. The synchronous rectification stage can be paralleled by mounting two further STL160N4F7 N-channel MOSFETs (Q2 and Q8), which can significantly reduce the operating temperatures of the mounted synchronous rectifier MOSFETs. Figure 1. STEVAL-ISA204V1 block diagram 48V Input Forward Converter Input Filter Active Clamp Reset PWM peak current mode controller for telecom systems Synchronous Rectification Output Filter N-channel Mosfet GAT1 PM8804 Load Output 5V 20A GAT2 Adjustable shunt Voltage Reference VCC Feedback Circuit (TS431AILT) Feedback Optocoupler RELATED LINKS Visit the Server & Telecom application page for more information on relevant power supply and conversion strategies DB3958 - Rev 1 page 2/7 STEVAL-ISA204V1 Electrical and efficiency characteristics 2 Electrical and efficiency characteristics Table 1. Electrical specifications of STEVAL-ISA204V1 Electrical specifications Range / Value Input voltage range 42 - 56 V DC Output voltage 5V Output current 20 A Total output power 100 W Maximum efficiency > 94 % The STEVAL-ISA204V1 evaluation board attains a maximum efficiency of 94%. The figure below shows the efficiency of the board at different input voltages and load conditions. Figure 2. Efficiency at different load conditions 96 Efficiency % 94 92 48 V 56 V 42 V 90 88 86 84 10 20 30 40 50 60 Load % 70 80 90 100 Table 2. STEVAL-ISA204V1 MOSFET temperatures at maximum load (20 A) Optional Q2 and Q8 DB3958 - Rev 1 Synchronous rectifier Q1 Synchronous rectifier Q5 Forward Converter Q4 unmounted 84 C 94.4C 74 C mounted 74 C 77.8 C 73 C page 3/7 STEVAL-ISA204V1 Board layout 3 Board layout Figure 3. STEVAL-ISA204V1 top layer Figure 4. STEVAL-ISA204V1 bottom layer DB3958 - Rev 1 page 4/7 DB3958 - Rev 1 4 Schematic diagram 100W - 48V TO 5V - FORWARD CONVERTER BASED ON PM8804 INPUT 48 V TP6 TP-Black C32 C33 4.7uF 1210 100V 4.7uF 1210 100V 4.7uF 1210 100V Input Filter 2 8 4 10 1K C75 100pF 0805 50V NC R35 0805 SGND PGND D5 D6 D7 D8 R56 10K 0603 Q11 PBSS5240T-NM SOT23 D17 BZX84C10 SOT23 C76 100pF NC 0805 50V D2 BZX84C10 SOT23 Q8 NM powerFLAT 5x6 G4 GSH S1 S2 S3 S1 S2 S3 T4 POE120PL-xxL_-NM BAS16J SOD323 Q12 PBSS4240T SOT23 R34 0805 C C31 D16 22R A 2 1 Header 2 SGND C29 33uF 100V C30 10x10.2 NM EEEFK2A330P 0805 VSN C P1 C24 4.7uF 1210 100V Q2 NM powerFLAT 5x6 NM 0805 D1 BAS16J GSL G4 SOD323 R37 R17 Q9 10K 22R 0805 PBSS4240T SOT23 0603 R29 Q10 1K 0805 PBSS5240T-NM SOT23 VSP NM R33 0805 D5 D6 D7 D8 R16 C20 NM A L1 Wurth 74439346056 1 5.6uH 2 2KV 1812 C28 NM 0805 VSP VSN TP5 TP-Red SGND 5 Gate Driving of MOSFET 1 6 1 VSP C47 2.2uF 25V 0603 R62 5.6K 0805 GSL D48 BAS16J SOD323 STL160N4F7 powerFLAT 5x6 C54 2.2nF NC D11 BZX84C10-NM SOT23 R124 10R 0805 R32 10R 0805 C36 C37 C38 C40 C41 C42 C43 47uF 1210 16V 47uF 1210 16V 47uF 1210 16V 47uF 1210 16V 47uF 1210 16V 47uF 1210 16V 330uF 16V 8x10.5 SGND 2KV 1812 PGND G4 C95 1nF 0805 100V C39 1nF 0805 100V J6 Synchronous rectifiers TP9 TP11 TP-Black Turret R49 0E 0805 D5 D6 D7 D8 C25 0603 100nF Q7 FDMC86259P G4 powerFLAT 3x3 G4 25V S1 S2 S3 0E R44 0R05 1210 R108 0R05 1210 D12 BAS70 SOD323 R25 10K 0603 R51 560R Q6 FDMS86263P - NM powerFLAT 5x6 Note: Q6 - Do not Mount C58 100nF 25V 0603 R52 20k 1% SGND D50 BAS70 SOD323 R125 47K D49 BAS70 SOD323 C60 C59220pF R531% 22nF AGND C96 2.2uF 25V 0603 Power circuit 4.7K 2 U12 NM SOT23 2 4 1 U4 TS431AILT SOT23-5 R54 15K 1% R55 12k 1% Feedback circuit AGND PGND C57 22nF 3 R40 10K NM C55 100nF 25V 0603 2 FOD817AS C56 5 C50 100nF 25V 0603 3 R50 220R C49 NM 1206 200V R48 10R 1 1 TP12 TP-Red 4 3 MODE C52 NM C48 47nF 1206 200V R15 NM 1206 D5 D6 D7 D8 12 U2 PM8804 13 G4 S1 S2 S3 D13 BAS16J SOD323 R47 R41 NM 1% U3 Q4 BSC190N15NS3 powerFLAT 5x6 S1 S2 S3 R38 10R 0805 D5 D6 D7 D8 7 6 TP7 TP-Red 8 VIN Ex Pad 17 VC 16 1% R43130K NC2 5 AGND PGD NC1 1 PGND R78 0R 1206 GAT1 9 PGND 10 GAT2 11 CS SS CTL DT 2 BLK FSW 3 C5333nF 14 4 R45 1% 270K 15 1% R46 91K D15 SGND SGND C51 1nF 0805 100V C44 100nF 0603 VOUT Led D5 D6 D7 D8 6 G4 STL160N4F7 powerFLAT 5x6 R61 3.3K 0805 O U T P U T 5 V /2 0 A C45 100nF 25V 0603 GSH Q1 S1 S2 S3 Q3 MMBT3904LT1-NM SOT23 R31 NM 0603 J4 Q5 VSN 5 A C46 1nF 0805 100V D9 L9 LPS4018-105MLBAS16J 2 SOD323 1 C TP18 TP-Yellow R28 0R 0603 R30 240K 0805 9 8 7 L4 SER2013-362L 2 D5 D6 D7 D8 TP14 TP-Red Auxiliary voltage 2 1 TP10 TP8 TP-Red Turret TP13 TP-Red T3 RA7129-BL 12 11 10 3 4 S1 S2 S3 R36 0805 10R SGND STEVAL-ISA204V1 Schematic diagram page 5/7 STEVAL-ISA204V1 Revision history Table 3. Document revision history DB3958 - Rev 1 Date Version 14-Jun-2019 1 Changes Initial release. page 6/7 STEVAL-ISA204V1 IMPORTANT NOTICE - PLEASE READ CAREFULLY STMicroelectronics NV and its subsidiaries ("ST") reserve the right to make changes, corrections, enhancements, modifications, and improvements to ST products and/or to this document at any time without notice. Purchasers should obtain the latest relevant information on ST products before placing orders. ST products are sold pursuant to ST's terms and conditions of sale in place at the time of order acknowledgement. Purchasers are solely responsible for the choice, selection, and use of ST products and ST assumes no liability for application assistance or the design of Purchasers' products. No license, express or implied, to any intellectual property right is granted by ST herein. Resale of ST products with provisions different from the information set forth herein shall void any warranty granted by ST for such product. ST and the ST logo are trademarks of ST. For additional information about ST trademarks, please refer to www.st.com/trademarks. All other product or service names are the property of their respective owners. Information in this document supersedes and replaces information previously supplied in any prior versions of this document. (c) 2019 STMicroelectronics - All rights reserved DB3958 - Rev 1 page 7/7