AN3373 STMICROELECTRONICS | Alldatasheet
Document overview
- Manufacturer or author: Provided By ALLDATASHEET.COM(FREE DATASHEET DOWNLOAD SITE)
- PDF pages: 18
Technical content
Datasheet sections
- 1 Electrical specifications
- 2 Demonstration kit schematic
- 3 Bill of material
- 4 Test results
- 4.1 Efficiency measurements wi th synchronous rectification
- 4.2 Converter waveforms
- 4.2.1 Startup sequence from PoE injectors
- 4.2.2 Primary side MOSFET
- 4.2.3 Secondary side MOSFET
- 4.2.4 Load transient
- 4.2.5 Output ripple
1 Electrical specifications
Table 1. Specifications for 3.3 V output
2 Demonstration kit schematic
Figure 2. Demonstration kit schematic: detail of the input section including data
Figure 3. Demonstration kit schematic: detail of the PoE converter based on
3 Bill of material
Ta bl e 2 shows the bill of material for the PoE converter based on the PM8803. Table 2. Bill of material
1 EVALPM8803 FL Y rev1 Board PCB
8 C1,C2,C3,C4,C11C36,C44,C45 Ceramic capacitor 100 nF 50 V 603 Std
4 C5,C6,C7,C8 Ceramic capacitor 10 nF 10% 100 V 603 TDK
6 C10,C39,C41,C48C53,C59 Ceramic capacitor 1 µF 20% 16 V 603 Std
3 C14,C16,C21 Ceramic capacitor 1 nF 10% 100 V 603 TDK
2 C19,C38 Ceramic capacitor 22 nF 50 V 603 Std
2 C28,C29 Ceramic capacitor 1 µF 20% 100 V 1206 TDK
1 C31 Ceramic capacitor 1 nF 10% 100 V 805 Std
1 C49 Ceramic capacitor 10 nF 50 V 603 Std
1 C50 Ceramic capacitor 100 nF 50 V 603 Std
1 C54 Ceramic capacitor 470 pF 50 V 603 Std
1 C55 Ceramic capacitor 100 pF 50 V 603 Std
1 C56 Ceramic capacitor 22 nF 50 V 603 Std
1 D1,D21 Std diode STTH1R02A 200 V SMC ST
1 D32 Zener diode BZX84C10 SOT23 Std
8 D4,D7,D8,D9,D12D13,D14, D17 Schottky diode STPS1H100A 100 V SMA ST
1 D11 TVS diode SMAJ58A SMA ST
1 D23 Schottky diode STPS1H100A 100 V SMA ST
6 D28,D34,D36,D37D39,D40 Schottky diode BAT46J 100 V SOD323 ST
2 J1,J2 Power jack SA,SP Std
1 J3 RJ45 connector Data & power input Std
1 J4 RJ45 connector Data output Std
1 L5 SMT inductor 10 µH MSS7341-103ML Coilcraft
1 Q12 Mosfet N-channel STS10N3LH5 30 V SO8 ST
1 Q16 Transistor, PNP MMBT3906LT1 40 V SOT23 Std
1 Q17 Mosfet N-channel STS1NF20 200 V SOT223 ST
4 R10,R11,R12,R13 Chip resistor 75 Ω 603 Std
6 R17,R26,R37,R43
2 R27,R58 Chip resistor 124 k Ω 1% 603 Std
2 R32,R51 Chip resistor 100 k Ω 805 Std
Table 2. Bill of material (continued)
4 R38,R65,R89,
1 R53 Chip resistor 4R7 1206 Std
3 R60,R64,R68 Chip resistor 0 Ω 603 Std
1 R62 Chip resistor 68 Ω 603 Std
1 R72 Chip resistor 91 k Ω 1% 603 Std
1 R80 Chip resistor 47 Ω 603 Std
2 R83,R107 Chip resistor 100 k Ω 603 Std
1 R91 Chip resistor 10 Ω 603 Std
1 R92 Chip resistor 150 Ω 603 Std
1 R93 Chip resistor 680 Ω 603 Std
1 R94 Chip resistor 21 k Ω 1% 603 Std
1 R96 Chip resistor 0 Ω 603 Std
2 R99,R101 Chip resistor 51 k Ω 1% 603 Std
1 R102 Chip resistor 80R6 1% 805 Std
1 R103 Chip resistor 510 Ω 603 Std
2 T1,T2 POE+ Magnetics ETH1-230LD Coilcraft
1 T7 Power transformer POE13P-33L Coilcraft
1 T8 Gate driver transformer DA2319-AL Coilcraft
1 U1 POE+ controller PM8803 HTSSOP20 ST
1 U3 SMT optocoupler Fairchild FOD817AS 4PDIP Fairchild
1 U4 Shunt regulator TS431AILT SOT23-5 ST
4 Test results
4.1 Efficiency measurements wi th synchronous rectification
Figure 4. Efficiency measurements at 48 V input Figure 5. Converter efficiency vs. input power The difference between DC-DC and overall measurements is about 2% from 0.8 A to 2 A.
4.2 Converter waveforms
4.2.1 Startup sequence fr om PoE injectors
Figure 6. Startup from an IEEE 802.3af injector with 2 A load
4.2.2 Primary side MOSFET
Figure 7. Primary side power MOSFET waveforms at 0 A load
Figure 8. Primary side power MOSFET waveforms at 2 A load
4.2.3 Secondary side MOSFET
Figure 9. Secondary side power MOSFET waveforms at 0 A load
4.2.4 Load transient
Figure 12. Response of the converter to a 1 A - 2 A load transient Figure 13. Response of the converter to a 0 A - 2 A load transient
4.2.5 Output ripple
Figure 14. Output ripple measurement at 2 A Figure 15. Output ripple measurement at 2 A with infinite persistence
Revision history
Table 3. Document revision history