UM1062 User manual EVALPM8803-FWD: IEEE802.3at compliant demonstration kit with synchronous active clamp forward converter Introduction The PM8803 is a highly integrated device embedding an IEEE802.3at-2009 compliant powered device (PD) interface together with a PWM controller and support for auxiliary sources. Figure 1 is an image of the EVALPM8803-FWD PoE+ demonstration board. The same PCB can be populated with different components to support various configurations and options (active clamp forward both with synchronous rectification or with diode rectification). This document focuses on a reference design for PoE+ based on AC forward topology with synchronous rectification, with the PM8803 as the main controller. The schematics and board layout of the PoE+ section are given in Section 2 and 3 while the related bill of material is detailed in Section 5. In Section 7 efficiency measurements together with main waveforms of the PoE interface and AC forward converter are shown. Figure 1. March 2011 EVALPM8803-FWD demonstration kit Doc ID 018571 Rev 1 1/31 www.st.com Contents UM1062 Contents 1 Electrical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2 Demonstration kit schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 3 Board layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 4 I/O connectors and test points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 5 Bill of material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 6 Power-up sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 7 Test results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 8 2/31 7.1 Efficiency measurement with 3.3 V output . . . . . . . . . . . . . . . . . . . . . . . . 20 7.2 Efficiency measurement with 5 V output . . . . . . . . . . . . . . . . . . . . . . . . . 21 7.3 Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 7.3.1 Startup sequence from PoE/PoE+ injectors . . . . . . . . . . . . . . . . . . . . . . 23 7.3.2 Transition from PoE to auxiliary and auxiliary to PoE . . . . . . . . . . . . . . 24 7.3.3 Primary side MOSFET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 7.3.4 Secondary side MOSFET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 7.3.5 Line transient . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 7.3.6 Load transient . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 7.3.7 Output ripple . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Doc ID 018571 Rev 1 UM1062 List of tables List of tables Table 1. Table 2. Table 3. Table 4. Table 5. Table 6. Table 7. Specifications for 3.3 V output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Specifications for 5 V output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 LEDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Test points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 EVALPM8803-FWD BOM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Doc ID 018571 Rev 1 3/31 List of figures UM1062 List of figures Figure 1. Figure 2. Figure 3. Figure 4. Figure 5. Figure 6. Figure 7. Figure 8. Figure 9. Figure 10. Figure 11. Figure 12. Figure 13. Figure 14. Figure 15. Figure 16. Figure 17. Figure 18. Figure 19. Figure 20. Figure 21. Figure 22. Figure 23. Figure 24. Figure 25. Figure 26. Figure 27. Figure 28. 4/31 EVALPM8803-FWD demonstration kit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Demonstration kit schematic: detail of the PoE+ input section including data transformer, diode bridges, protection, and optional CM choke . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Demonstration kit schematic: detail of the PoE+ section based on AC forward topology with synchronous rectification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Assembly view: top layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Assembly view: bottom layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Top layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Inner layer 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Inner layer 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Bottom layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Efficiency measurements at 48 V input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 DC-DC only efficiency measurements at different input voltages. . . . . . . . . . . . . . . . . . . . 20 Overall efficiency measurements at different input voltages. . . . . . . . . . . . . . . . . . . . . . . . 21 Efficiency measurements at 48 V input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 DC-DC only efficiency measurements at different input voltages. . . . . . . . . . . . . . . . . . . . 22 Overall efficiency measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Startup from an IEEE 802.3af injector with 2 A load. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Startup from an IEEE 802.3at injector with 4 A load. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Switching between PoE and auxiliary source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Primary side power MOSFET waveforms at 0 A load. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Primary side power MOSFET waveforms at 4 A load. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Secondary side power MOSFET waveforms at 0 A load . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Secondary side power MOSFET waveforms at 4 A load . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Effect of a 12 V line transient on the converter at 4 A load. . . . . . . . . . . . . . . . . . . . . . . . . 27 Effect of a 12 V line transient on the converter at 0 A load. . . . . . . . . . . . . . . . . . . . . . . . . 27 Response of the converter to a 2 A - 4 A load transient . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Response of the converter to a 0 A - 4 A load transient . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 5 V output ripple measurement at 4 A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 5 V output ripple measurement at 4 A with infinite persistence . . . . . . . . . . . . . . . . . . . . . 29 Doc ID 018571 Rev 1 UM1062 1 Electrical specifications Electrical specifications Table 1. Specifications for 3.3 V output Parameter Description Min. Input voltage range Applied at J3 connector Operative input voltage Typ. Max. Unit 0 57 V 42 57 V 36 V Vin rising edge UVLO Vin falling edge Auxiliary input voltage range 30 V 35 Output voltage (Vout) Vin= 42 V to 57 V, Iout 0 to Imax 3.25 Output current (Iout) Vin= 42 V to 57 V 0 Peak-to-peak output ripple 48 Vin, Iout=Imax 3.35 30 60 V 3.45 V 6 A 40 mVpp Inrush current limit 140 mA DC current limit 640 mA 3.3 V efficiency DC-DC only Vin=48 V, Iout=Imax 92 % 3.3 V overall efficiency Vin=48 V, Iout=Imax 89 % 200 kHz Switching frequency Table 2. Specifications for 5 V output Parameter Description Min. Input voltage range Applied at J3 connector Operative input voltage Typ. Max. Unit 0 57 V 42 57 V 36 V Vin rising edge UVLO Vin falling edge Auxiliary input voltage range 30 V 35 Output voltage (Vout) Vin= 42 V to 57 V, Iout 0 to Imax 4.95 Output current (Iout) Vin= 42 V to 57 V 0 Peak-to-peak output ripple 48Vin, Iout=Imax 5.1 30 60 V 5.25 V 4 A 40 mVpp Inrush current limit 140 mA DC current limit 640 mA 5 V efficiency DC-DC only Vin=48 V, Iout=Imax 92 % 5 V overall efficiency Vin=48 V, Iout=Imax 89 % 200 kHz Switching frequency Doc ID 018571 Rev 1 5/31 !58 #HASSIS 40 40 2 2 2 2 + 2 !UXILIARYINPUTFRONTALOR!58) 30 * $!4!0/7%2).054 * # . $ $ 3-! 3403(! $ 3-! 3403(! 3-# 344(3 3-! $ 3-! 3403(! /PTION3TANDARD $IODE"RIDGE .OT-OUNTED 30 $ 2 .- 3403(! 2 . 2 .- 2 . #HASSIS # N& +6 2 . # N& 6 # N& 6 # N& 6 2 2 2 2 2 2 /PTION!CTIVE"RIDGE .OT-OUNTED # N& 6 2 2 $ 3-! 3403(! $ 3-! 3403(! 4 3-! $ %4(,$ 4 %4(,$ 3403(! 3-! 3403(! $ /PTION3TANDARD $IODE"RIDGE .OT-OUNTED # N& 6 2 2 2 2 # .+6 # N& 6 #HASSIS # N& 6 40 /PTION!CTIVE"RIDGE .OT-OUNTED # N& 6 2 2 2 .- 40 3-! .- $ 40 # . 6 24. # . 6 #HASSIS # . 6 2 &ERRITE"EADOHM! 633 0/%& &ERRITE"EADOHM! 2 7URTH3 4.- #HASSIS /PTION )NPUT#OMMON-ODE&ILTER .OT-OUNTED 6/54 /PTION $IFFERENTPOSITIONFOR463AND #-CHOKE"YPASSCAPACITORS .OT-OUNTED 2 .- 2 # N& 6 40 # N& 6 # U& 6 2 2 2 Doc ID 018571 Rev 1 6/31 #HASSIS # U& 6 * 3-! # N& 6 24. 3-!*! $ # N& 6 633 0/%& $!4!/54054 Demonstration kit schematic UM1062 2 Demonstration kit schematic Figure 2. Demonstration kit schematic: detail of the PoE+ input section including data transformer, diode bridges, protection, and optional CM choke !-V Doc ID 018571 Rev 1 633 30 N& # 0/%& 2 + 2 + 3! # .- 2 2 6$$ 6$$ $%4 30 #,3 $##, 3! $4 &23 40 5 2 K 2 + (433/0 0- 40 2 2 2 . # . 0-CIRCUIT 2 4"$ 2 K 2 $ .3-! # 633 24. !24. '!4 6# '!4 24. #3 6" #4, + ./4%FOR*UMPERS*-AND*- -OVETHESHORTONBOTHJUMPERSATTHESAMETIME SHORTBETWEENPINANDWHENUSED!58INPUT SHORTBETWEENPINANDWHENUSED!58INPUT 2 ./4%FOR#APACITORS 7HERENOTINDICATEDTHEBODYISANDTHEVOLTAGEIS6 N& # 2 + $ # U 6 .- # # P& 2 .- &AIRCHILD&/$!3 5 # U 6 + !24. # U& 6 X /PTION $ISCRETE,INEAR2EGULATOR ON6# .OT-OUNTED # U& 6 2 2 2 !24. 2 + 40 40 *- *UMPERDOPPIO 3-# 344(3 .- 6 2 + ./4%FOR2ESISTORS 7HERENOTINDICATEDTHEBODYISANDTOLERANCE .- # 2 + *- *UMPERDOPPIO 2 2 40 2 + 2 40 , U( $ !58 2 2 M( $ 3/$ "!4* 24. 40 !5802%3%.4 6/54 2 + 3/$ "!4* $ 3/$ 2 2 2 2 2 "!4* $ U& 6 # 0OWERCIRCUIT 2 !58 K , U& 6 # 40 ,03-, 24. 40 # U 6 )NPUT&ILTER -33-, 1 3/ $ 3/$ 40 2 + N& "!4* 1 3I$3 3/4 # N& 6 3/$ $ 3/0720!+3/ 2 2 2 !CTIVE#LAMP 3/$ "!4* 2 "!4* 2 $ # 2 40 1 2 /PTION $IODE2ECTIFICATION WITH$0AKBODY .OT-OUNTED 343.,,( 40 40 2 .- # .- $ 2 2 N& # 5 # N 3/$ +6 # U 6 "!4* $ &AIRCHILD&/$!3 40 3/0720!+3/ 343.,,( 1 5 &AIRCHILD&/$!3 24. # N& 2 2 !24. 3/$ "!4* 2 2 2 2 .- , U( 3%2+, ./4% 4HE!24.ISADEDICATEDPLANEOFSIGNALGROUNDTHATWILLBECONNECTEDTOTHE 24.POWERGROUNDPLANECLOSETOPINANDOF0- # N& 3I$9 2 OHM 24. 24. 2 OHM 40 !24. 40 40 4 #OILCRAFT(A!, 6!58 /PTION ALTERNATIVEPOWERTRANSFORMERS FORESEENONTHEPCB 0/%0SERIESIN%0 0/%&SERIESIN%&$ .OT-OUNTED # U& 6 X # 2 N& # .- # U& 6 $ ,/+ 2 + 40 ,OK ,/+ 2 2 2 $ 2 + 2 + 2 + P& U 6 # 6OUT /UTPUT&ILTER U 6 # &EEDBACKCIRCUIT 3/4 5 3/$ "!4* $ 2 2 43!),4 2 + # N& /PTION $IODE2ECTIFICATION WITH$0AKBODY .OT-OUNTED * %X0AD '2%%.,%$ 2 K 2 K 40 # N& 40 * Figure 3. UM1062 Demonstration kit schematic Demonstration kit schematic: detail of the PoE+ section based on AC forward topology with synchronous rectification !-V 7/31 Board layout 3 UM1062 Board layout Board size: 6 x 16 cm. Layer copper thickness: 70 micron. Figure 4. Assembly view: top layer !-V Figure 5. Assembly view: bottom layer !-V 8/31 Doc ID 018571 Rev 1 UM1062 Figure 6. Board layout Top layer !-V Figure 7. Inner layer 1 !-V Doc ID 018571 Rev 1 9/31 Board layout Figure 8. UM1062 Inner layer 2 !-V Figure 9. Bottom layer !-V 10/31 Doc ID 018571 Rev 1 UM1062 4 I/O connectors and test points I/O connectors and test points This section provides a description of input/output connectors (Table 3), LED indicators and commands (Table 4), as well as the available test points (Table 5). Table 3. Connectors Connector Label Description Data and power Power and Ethernet data input port input J3 J4 Data output J2 SP Wall adapter input. Use this input jack to connect auxiliary source without priority of the auxiliary source wrt PoE. J1 SA Wall adapter input. Use this input jack to connect auxiliary source with priority of the auxiliary source wrt PoE. J5 - Output voltage connector - Move the short on both jumpers at the same time: short between pin 1 and 2 when SA auxiliary source is used on J1 connector; short between pin 2 and 3 when SP auxiliary source is used on J2 connector - Move the short on both jumpers at the same time: short between pin 1 and 2 when SA auxiliary source is used on J1 connector; short between pin 2 and 3 when SP auxiliary source is used on J2 connector LED Label Description D20 AUX ON when an auxiliary source is applied to the board; proper selection of the auxiliary source connection is done with jumpers JM1 and JM2 D44 L1_OK ON when T2P is asserted. This is achieved when a 2-finger event is detected. If, after a successful PoE+ layer-1 classification, an auxiliary voltage is connected, the T2P signal is de-asserted and the L1_OK LED is turned off. D26 GREEN LED JM1 JM2 Table 4. Table 5. Ethernet data output port LEDs ON when output voltage is present. Test points Test point Color Description TP1 Red Data transformer bias voltage TP2 Red Positive of auxiliary source AUX 1 on J2 TP3 Black Auxiliary source AUX 1 ground on J2 TP4 Red Input voltage VDD TP5 Red Secondary winding output TP6 Red Output voltage on J5 Doc ID 018571 Rev 1 11/31 I/O connectors and test points Table 5. 12/31 UM1062 Test points (continued) Test point Color Description TP7 Red Positive of auxiliary source AUX 2 on J1 TP8 Black Auxiliary source AUX 2 ground on J1 TP9 Red Input of the primary side winding TP10 Red Secondary winding output TP11 Red VSS - I/F ground voltage TP12 Black Output voltage ground TP13 Red Gate drive of the secondary side MOSFET TP14 Red VC supply voltage TP15 Red Gate drive of the primary side MOSFET TP16 Red Drain of the primary side MOSFET TP17 Red Gate drive of the MOSFET connected to GAT2 TP18 Red Current sense input TP19 Black RTN - DC-DC ground voltage TP20 Red L1 status indicator - referred to output voltage ground TP21 Red Aux present indicator - referred to output voltage ground TP22 Red PoE voltage after the input diode bridges TP23 Black Ground of the PoE voltage after the input diode bridges TP24 Black Chassis ground of the RJ45 connectors TP26 Red Gate drive of the secondary side MOSFET Doc ID 018571 Rev 1 Bill of material Bill of material 13/31 5 With minimal BOM changes it is possible to switch from 3.3 V to 5 V output voltage. Table 6. EVALPM8803-FWD BOM Doc ID 018571 Rev 1 3.3 V 5V Reference Description Value 1 1 EVALPM8803-FWD ACFWD rev1 Board PCB 7 7 C1,C2,C3,C4,C11C36, C57 Ceramic capacitor 100 nF 4 4 C5,C6,C7,C8 Ceramic capacitor 10 nF NM NM C9,C22 Ceramic capacitor NM 6 6 C10,C39,C41, C48,C53,C59 Ceramic capacitor 1 µF 1 1 C12 Ceramic capacitor NM NM C13,C20 3 3 NM Tol. Body Vendor 50 V 603 Std 100 V 603 TDK 1812 NM 16 V 603 Std 2.2 nF 2 kV 1812 TDK Ceramic capacitor NM 100 V 603 NM C14,C16,C21 Ceramic capacitor 1 nF 100 V 603 TDK NM C15,C17,C24,C60 Ceramic capacitor NM 100 V 805 NM 2 2 C18,C32 Ceramic capacitor 0.1 µF 100 V 805 TDK 2 2 C19, C38 Ceramic capacitor 22 nF 50 V 603 Std NM NM C42,C46,C56,C66C69 Ceramic capacitor NM 603 NM 1 1 C26 Aluminium capacitor 33 µF 20% 100 V 10x10.2 Std 2 2 C33,C35 Ceramic capacitor 10 µF 20% 6.3 V 805 Std 2 2 C28,C29 Ceramic capacitor 1 µF 20% 100 V 1206 TDK 2 2 C31,C37 Ceramic capacitor 1 nF 10% 100 V 805 Std 1 1 C34 Aluminium capacitor 330 µF 6.3 V 8x10.5 Suncon NM NM C40 Ceramic capacitor NM 805 NM NM NM C43 Aluminium capacitor NM 4x6 NM 10% 20% 10% 10% UM1062 Voltage EVALPM8803-FWD BOM (continued) 3.3 V 5V Reference Description Value NM NM C47 Ceramic capacitor NM 1 1 C49 Ceramic capacitor 22 nF 1 1 C50 Ceramic capacitor 1 1 C51 1 1 1 Tol. Voltage Doc ID 018571 Rev 1 Vendor 603 NM 50 V 603 Std 100 nF 50 V 603 Std Ceramic capacitor 47 nF 200 V 1206 Syfer C54 Ceramic capacitor 470 pF 50 V 603 Std 1 C55 Ceramic capacitor 100 pF 50 V 603 Std 1 1 C56 Ceramic capacitor 22 nF 50 V 603 Std 1 1 C61 Ceramic capacitor 2.2 nF 2 kV 1812 TDK 1 1 D1, D21 Std diode STTH302S 200 V SMC STMicroelectronics NM NM D2,D3,D5,D6, D15D16,D18,D19 Zener diode (BZX84C10) SOT23 NM 1 1 D32 Zener diode BZX84C10 SOT23 Std 8 8 D4,D7,D8,D9, D12D13,D14, D17 Schottky diode STPS2H100A SMA STMicroelectronics NM NM D10 TVS diode NM SMA NM 1 1 D11 TVS diode SMAJ58A SMA STMicroelectronics 1 1 D20 LED diode AUX PLCC-2 Std NM NM D22,D23 Schottky diode NM Dpak Option diode rect. NM NM D24,D25 Bridge rectifier NM SDIP NM 1 1 D26 LED diode Green LED PLCC-2 Std NM NM D27 Zener diode NM SOT23 NM 9 9 D28,D29,D30, D31D37,D38, D39, D40D41 Schottky diode BAT46J SOD323 STMicroelectronics NM NM D42 Schottky diode NM SMA NM 1 1 D44 LED diode L1 OK PLCC-2 Std 100 V 2.2 V 2.2 V 100 V 2.2 V Bill of material 14/31 Body UM1062 Table 6. EVALPM8803-FWD BOM (continued) Doc ID 018571 Rev 1 5V Reference Description Value Tol. Voltage Body Vendor 2 2 JM1,JM2 Connector Jumper 3 pins male Pitch 2.54 mm Std 2 2 Jumper Jumper 2 pins female Pitch 2.54 mm Std 2 2 J1, J2 Power jack SA, SP Std 1 1 J3 RJ45 connector Data and power input Std 1 1 J4 RJ45 connector Data output Std 1 1 J5 Terminal block 2-way MOR-10X10.5-P5-2PIN Std 1 1 L2 SMT inductor 1 mH LPS4018-105ML Coilcraft NM 1 L3 SMT inductor 10 µH SER1360-103KL Coilcraft 1 NM L3 SMT inductor 6 µH SER1360-602KL Coilcraft 1 1 L5 SMT inductor 10 µH MSS7341-103ML Coilcraft NM NM Q1,Q2,Q3,Q4 MOSFET, P-ch IRF6216PbF 100 V SO8 IR NM NM Q5,Q6,Q7,Q8 MOSFET, N-ch STS4NF100 100 V SO8 STMicroelectronics 2 2 Q11,Q12 MOSFET, N-ch STS14N3LLH5 30 V SO8 STMicroelectronics 1 1 Q14 Transistor, NPN MMBT3904LT1 40 V SOT23 Std 1 1 Q17 MOSFET, N-ch Si4848DY 150 V SO8 Vishay 1 1 Q20 MOSFET, P-ch Si2325DS 150 V SOT23 Vishay NM NM Q21 MOSFET, P-ch IRF6216PbF 150 V SO8 NM 4 4 R1,R2,R5,R7 Chip resistor 0 603 Std NM NM R3,R4,R6,R8,R16 Chip resistor NM 805 NM 4 4 R10,R11,R12,R13 Chip resistor 75 Ω 603 Std NM NM R14,R125 Chip resistor NM 1206 NM 1 1 R15 Chip resistor 0 805 Std 2 2 R17,R43 Ferrite bead MPZ012101A 805 TDK 4 4 R26,R37,R49,R54 Chip resistor 0 805 Std 100 Ω, 4A UM1062 3.3 V Bill of material 15/31 Table 6. EVALPM8803-FWD BOM (continued) 3.3 V 5V Reference Description Value NM NM R19,R20,R22,R25R39, R40,R41,R42 Chip resistor NM 2 2 R27,R58 Chip resistor 124 kΩ NM NM R28,R29,R30,R31R33, R34,R35,R36R70,R100 ,R104, R120,R121 Chip resistor 2 2 R32,R51 3 3 3 Tol. Doc ID 018571 Rev 1 Vendor 603 NM 603 Std NM 603 NM Chip resistor 100 kΩ 805 Std R38,R65,R117 Chip resistor 4.75 kΩ 603 Std 3 R44,R52,R119 Chip resistor 1 kΩ 603 Std 2 2 R45,R99 Chip resistor 47 kΩ 603 Std 2 2 R53,R59 Chip resistor 10 Ω 805 Std 2 2 R57,R60 Chip resistor 5.6 Ω 805 Std 1 1 R62 Chip resistor 10 Ω 603 Std 3 3 R64,R68,R98 Chip resistor 0 603 Std NM NM R66,R97 Chip resistor NM 603 NM 2 2 R67,R106 Chip resistor 10 kΩ 603 Std 1 1 R72 Chip resistor 124 kΩ 603 Std 1 1 R73 Trimmer resistor 100 kΩ NM NM R79,R86 Chip resistor NM 805 NM 1 1 R89 Chip resistor 2.7 kΩ 603 Std 1 1 R90 Chip resistor 680 Ω 603 Std 1 1 R91 Chip resistor 10 Ω 603 Std 1 1 R92 Chip resistor 22 Ω 603 Std 1 NM R93 Chip resistor 680 Ω 603 Std NM 1 R93 Chip resistor 820 Ω 603 Std 1% 1% Vishay Bill of material 16/31 Body 1% Voltage UM1062 Table 6. EVALPM8803-FWD BOM (continued) 3.3 V 5V Reference Description Value Tol. 1 1 R94 Chip resistor 21 kΩ 1 1 R95 Chip resistor 24.9 kΩ 1 1 R96 Chip resistor NM NM R101 1 1 Doc ID 018571 Rev 1 Vendor 1% 603 Std 1% 603 Std 0 603 Std Chip resistor NM 603 NM R102 Chip resistor 35.7 Ω 805 Std 1 1 R103 Chip resistor 510 Ω 603 Std 1 1 R104 Chip resistor 4.75 kΩ 603 Std 1 1 R107 Chip resistor 100 kΩ 603 Std 2 2 R108,R109 Chip resistor 0.30 Ω 1206 Std low value 1 1 R111 Chip resistor 12.4 kΩ 1% 603 Std NM 1 R112 Chip resistor 15 kΩ 1% 603 Std 18 18 TP1,TP2,TP4,TP5TP6, TP7,TP9, TP10,TP13,TP14,TP15, TP16,TP17,TP18,TP20, TP21,TP22,TP26 Test points Red Std 7 7 TP3,TP8,TP11, TP12,TP19,TP23,TP24 Test points Black std 2 2 T1,T2 PoE+ magnetics ETH1-230LD Coilcraft NM NM T3 CM choke NM NM NM 1 T5 Power transformer HA3691-AL Coilcraft 1 NM T5 Power transformer JA4173-AL Coilcraft NM NM T6 Power transformer (PoE300F) NM NM NM T7 Power transformer (PoE13P) NM 1 1 U1 PoE+ controller PM8803 HTSSOP20 STMicroelectronics 3 3 U2,U3,U7 SMT optocoupler Fairchild FOD817AS 4PDIP Fairchild 1% UM1062 Body 1% Voltage Bill of material 17/31 Table 6. EVALPM8803-FWD BOM (continued) 3.3 V 5V Reference Description Value 1 1 U4 Shunt regulator NM NM U5 Shunt regulator Tol. Voltage Body Vendor TS431AILT SOT23-5 STMicroelectronics TS2431AILT SOT23 NM UM1062 Table 6. Doc ID 018571 Rev 1 Bill of material 18/31 UM1062 6 Power-up sequence Power-up sequence It is recommended to apply power at PoE input first, slowly increasing the voltage to verify the absence of abnormal input current levels. From about 2 V to about 12 V input, the demonstration kit performs the detection signature. At 10 V input the current drawn is about 400 µA. In the range of 14 V to 23 V, the demonstration kit performs a class-4 classification, and the current drawn is about 40 mA. After those two steps are verified, the voltage can be increased to 48 V typical. The PoE converter starts operations at about 36 V input. Three green LEDs indicate proper operation of the PoE and DC-DC section of the PM8803 demonstration kit: Note: ● D44 is the T2P LED and is ON when the PM8803 has successfully recognized a type 2 PSE or a 802.3at compliant injector; using a bench power supply to power up the PM8803 demonstration board, this LED is OFF. ● D26 indicates the presence of the output voltage. ● D20 is the AUX LED and indicates the presence of an auxiliary voltage applied to the converter; proper selection of the auxiliary voltage is done with jumper JM1 and JM2: put a short between pin 1 and 2 when SA auxiliary source on J1 connector is used; put the short between pin 2 and 3 when SP auxiliary source on J2 connector is used. Set the R73 trimmer at a value around 10 kΩ. Adjust this value for best converter performances in terms of efficiency over its actual load range. Note: In the case of SA external auxiliary source tests, it is strongly recommended to change the position of the 100 nF, 100 V from C18, at the input filter, where it is soldered to C60, across the internal hot-swap MOSFET. This change of position, that has no impact on the standard compliance, permits an optimal behavior of the PM8803 device during the change of ground reference consequent to the power jack insertion/removal. Doc ID 018571 Rev 1 19/31 Test results UM1062 7 Test results 7.1 Efficiency measurement with 3.3 V output Figure 10. Efficiency measurements at 48 V input 9RXWHIILFLHQF\#9 (IILFLHQF\>@ '&'&RQO\ RYHUDOO ,RXW>$@ !-V Figure 11. DC-DC only efficiency measurements at different input voltages 9RXW'&'&RQO\HIILFLHQF\ (IILFLHQF\>@ '&'&9 '&'&9 '&'&9 ,RXW>$@ 20/31 Doc ID 018571 Rev 1 !-V UM1062 Test results Figure 12. Overall efficiency measurements at different input voltages 9RXWRYHUDOOHIILFLHQF\ (IILFLHQF\>@ RYHUDOO9 RYHUDOO9 RYHUDOO9 ,RXW>$@ !-V Efficiency measurement with 5 V output Figure 13. Efficiency measurements at 48 V input 9RXWHIILFLHQF\#9 (IILFLHQF\>@ 7.2 RYHUDOO '&'&RQO\ ,RXW>$@ Doc ID 018571 Rev 1 !-V 21/31 Test results UM1062 Figure 14. DC-DC only efficiency measurements at different input voltages 9RXW'&'&RQO\HIILFLHQF\ (IILFLHQF\>@ '&'&9 '&'&9 '&'&9 ,RXW>$@ !-V Figure 15. Overall efficiency measurements 9RXWRYHUDOOHIILFLHQF\ (IILFLHQF\>@ RYHUDOO9 RYHUDOO9 RYHUDOO9 ,RXW>$@ 22/31 Doc ID 018571 Rev 1 !-V UM1062 7.3 Test results Waveforms The following images were taken on a 5 V output demonstration board. Similar waveforms are also applicable for the 3.3 V output version. 7.3.1 Startup sequence from PoE/PoE+ injectors Figure 16. Startup from an IEEE 802.3af injector with 2 A load Note the inrush current limited at about 140 mA and the T2P signal not asserted. Figure 17. Startup from an IEEE 802.3at injector with 4 A load Doc ID 018571 Rev 1 23/31 Test results UM1062 Note, in this case, the presence of the 2-finger during the classification phase and theT2P signal now asserted (T2P is valid low). 7.3.2 Transition from PoE to auxiliary and auxiliary to PoE Figure 18 shows the behavior of the PM8803 when commuting sources. The image depicts the transition from PoE to an auxiliary source whose voltage is ~10 V lower then PoE. It can be seen that when the auxiliary voltage is applied (SA pin goes above its threshold) the current drawn from the PoE drops to a few milliAmps. Smooth transition occurs as can be seen from the output voltage (blue line). Figure 18. Switching between PoE and auxiliary source 24/31 Doc ID 018571 Rev 1 UM1062 7.3.3 Test results Primary side MOSFET Figure 19. Primary side power MOSFET waveforms at 0 A load Figure 20. Primary side power MOSFET waveforms at 4 A load Doc ID 018571 Rev 1 25/31 Test results 7.3.4 UM1062 Secondary side MOSFET Figure 21. Secondary side power MOSFET waveforms at 0 A load Figure 22. Secondary side power MOSFET waveforms at 4 A load 26/31 Doc ID 018571 Rev 1 UM1062 7.3.5 Test results Line transient Figure 23 depicts the effect of a line transient on the PoE converter. A 12 V step on a 42 V input PoE line (green trace) is shown. The hot-swap MOSFET (yellow trace) withstands the transient while the input current (pink trace) is limited during the input capacitor charge; the converter continues to work and the output voltage (blue trace) remains in regulation. Figure 23. Effect of a 12 V line transient on the converter at 4 A load Figure 24. Effect of a 12 V line transient on the converter at 0 A load Doc ID 018571 Rev 1 27/31 Test results 7.3.6 UM1062 Load transient Figure 25. Response of the converter to a 2 A - 4 A load transient Figure 26. Response of the converter to a 0 A - 4 A load transient 28/31 Doc ID 018571 Rev 1 UM1062 7.3.7 Test results Output ripple Figure 27. 5 V output ripple measurement at 4 A Figure 28. 5 V output ripple measurement at 4 A with infinite persistence Doc ID 018571 Rev 1 29/31 Revision history 8 UM1062 Revision history Table 7. 30/31 Document revision history Date Revision 23-Mar-2011 1 Changes Initial release. Doc ID 018571 Rev 1 UM1062 Please Read Carefully: Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries (“ST”) reserve the right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any time, without notice. All ST products are sold pursuant to ST’s terms and conditions of sale. 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