Reference Design SLVA475 – January 2012 Efficiency-Optimized, Synchronous Flyback, High-Power PoE Controller/Converter The TPS23754 is an IEEE 802.3at-compliant, powered-device (PD) controller and power supply controller optimized for isolated converter topologies. TPS23754EVM-420 (SLVU301) is targeted at 25-W, synchronous, flyback converter applications. The PMP6672B reference design starts with the TPS23754EVM-420 platform and improves the overall efficiency of the design. 5 6 Contents Description ................................................................................................................... 2 1.1 Design Improvement Summary .................................................................................. 2 1.2 Typical Applications ................................................................................................ 2 1.3 Features ............................................................................................................. 2 Electrical Performance Specifications .................................................................................... 3 Schematic .................................................................................................................... 4 Performance Data and Typical Characteristic Curves ................................................................. 5 4.1 Efficiency ............................................................................................................ 5 4.2 Load Regulation .................................................................................................... 5 4.3 Bode Plot ............................................................................................................ 6 4.4 Transient Response ............................................................................................... 7 4.5 Output Ripple ....................................................................................................... 7 4.6 Switch Node Voltage .............................................................................................. 8 4.7 Turnon Waveform .................................................................................................. 8 PMP6672B Assembly Drawing and PCB Layout ...................................................................... 10 Bill of Materials ............................................................................................................. 11 1 PMP6672B Schematic 1 2 3 4 List of Figures 2 3 4 5 6 7 8 9 10 11 ..................................................................................................... PMP6672B Efficiency ...................................................................................................... PMP6672B Load Regulation .............................................................................................. PMP6672B Loop Response Gain and Phase ........................................................................... PMP6672B Load Transient ................................................................................................ Output Ripple ................................................................................................................ Switching Node Waveform................................................................................................. Enable Turnon Waveform – No Output Load ........................................................................... Enable Turnon Waveform – Output Fully Loaded ...................................................................... Top-Side Layout .......................................................................................................... Bottom-Side Layout ....................................................................................................... 4 5 5 6 7 7 8 8 9 10 10 List of Tables 1 PMP6672B Electrical Performance Specifications (at 25°C) .......................................................... 3 2 PMP6672B Components List According to the Schematic Shown in SLVA475 – January 2012 Submit Documentation Feedback .............................................. Efficiency-Optimized, Synchronous Flyback, High-Power PoE Controller/Converter Copyright © 2012, Texas Instruments Incorporated 11 1 Description 1 www.ti.com Description The PMP6672B allows reference circuitry evaluation of the TPS23754. It contains input and output power connectors and an array of onboard test points for circuit evaluation. Modifications to TPS23754EVM-420 (SLVU301) are noted on the schematic shown in Figure 1. 1.1 Design Improvement Summary • • • • • • • • • • • • 1.2 Typical Applications • • • 1.3 Voice over Internet Protocol – IP telephones Wireless LAN – wireless access points Security – wired IP cameras Features • • • • 2 New flyback transformer design Better selection of magnetizing inductance for CCM operation New winding strategy to reduce copper losses Uses same core and bobbin size and footprint RCD clamp improvements Diode used for faster primary FET turnoff New dead-time resistor value for optimum efficiency at full load and acceptable efficiency at no load. Use of feedforward resistor for better control of peak current and voltage at higher input voltage. Other updates: Compensation, improved slope compensation, 40-V synchronized FET for low drain-source stress. Other benefits Lower primary MOSFET peak drain-source voltage during overloads Much better current-limit control Efficient, general market design Self-driven, synchronous, rectified secondary 25-W output power from Power over Ethernet (PoE) or from a 48-V adapter 5-V output voltage Efficiency-Optimized, Synchronous Flyback, High-Power PoE Controller/Converter Copyright © 2012, Texas Instruments Incorporated SLVA475 – January 2012 Submit Documentation Feedback Electrical Performance Specifications www.ti.com 2 Electrical Performance Specifications Table 1. PMP6672B Electrical Performance Specifications (at 25°C) Parameter Condition Min Typ Max Units Power Interface Input voltage Applied to the power pins of connectors J2 or J3 Operating voltage After start-up 0 - 57 V 30 - 57 V Rising input voltage - - 36 Falling input voltage 30 - - Detection voltage At device terminals 1.6 - 10 V Classification voltage At device terminals 10 - 23 V Classification current Rclass = 63.4 Ω mA Input UVLO 36 - 44 Inrush current-limit 100 - 180 Operating current-limit 850 - 1100 V DC/DC Converter Output voltage 21.6 V ≤ Vin ≤ 57 V, ILOAD ≤ ILOAD (max) 5-V output 4.75 5 5.25 V Output current 21.6 V ≤ Vin ≤ 57 V 5-V output - - 5 A Output ripple voltage, peak-to-peak Vin = 48 V, ILOAD = 5 A 5-V output - 50 - mV Efficiency, Vin at J2 Efficiency, Vin at J3 Efficiency, Converter Vin = 48 V, ILOAD = 5 A 5-V output 275 kHz Switching frequency SLVA475 – January 2012 Submit Documentation Feedback 89% 91% 92% 225 - Efficiency-Optimized, Synchronous Flyback, High-Power PoE Controller/Converter Copyright © 2012, Texas Instruments Incorporated 3 Schematic Schematic + + + + 3 www.ti.com Figure 1. PMP6672B Schematic 4 Efficiency-Optimized, Synchronous Flyback, High-Power PoE Controller/Converter Copyright © 2012, Texas Instruments Incorporated SLVA475 – January 2012 Submit Documentation Feedback Performance Data and Typical Characteristic Curves www.ti.com 4 Performance Data and Typical Characteristic Curves Figure 2 through Figure 9 present typical performance curves for the PMP6672B. 4.1 Efficiency 95 90 85 PoE Input Converter Adapter Input Efficiency - % 80 75 70 65 60 55 50 0 1 2 3 4 5 IO - Output Current - A Figure 2. PMP6672B Efficiency 4.2 Load Regulation 5.1 5.09 VO - Output Voltage - V 5.08 5.07 VOUT 5.06 5.05 5.04 5.03 5.02 5.01 5 0 1 2 3 4 5 6 IO - Output Current - A Figure 3. PMP6672B Load Regulation SLVA475 – January 2012 Submit Documentation Feedback Efficiency-Optimized, Synchronous Flyback, High-Power PoE Controller/Converter Copyright © 2012, Texas Instruments Incorporated 5 Performance Data and Typical Characteristic Curves 4.3 www.ti.com Bode Plot Input voltage 48 Vdc Gain/Phase Crossover Phase Margin PMP6672B (5 V) 4.723 kHz 92° Figure 4. PMP6672B Loop Response Gain and Phase 6 Efficiency-Optimized, Synchronous Flyback, High-Power PoE Controller/Converter Copyright © 2012, Texas Instruments Incorporated SLVA475 – January 2012 Submit Documentation Feedback Performance Data and Typical Characteristic Curves www.ti.com 4.4 Transient Response Figure 5. PMP6672B Load Transient 4.5 Output Ripple VOUT Figure 6. Output Ripple SLVA475 – January 2012 Submit Documentation Feedback Efficiency-Optimized, Synchronous Flyback, High-Power PoE Controller/Converter Copyright © 2012, Texas Instruments Incorporated 7 Performance Data and Typical Characteristic Curves 4.6 www.ti.com Switch Node Voltage The following scope plot shows the waveforms on the drain of the secondary-side FET (Ch1) and primary-side FET (Ch2). The output is loaded at 5 A. Vin = 48 Vdc at J2. VQ1-D(SEC) VQ2-D(PRI) Figure 7. Switching Node Waveform 4.7 Turnon Waveform The following scope plot shows the 5-V output voltage start-up waveform after the application of 48 Vdc at J2 (PoE). The output was loaded to 0 A. VOUT Figure 8. Enable Turnon Waveform – No Output Load 8 Efficiency-Optimized, Synchronous Flyback, High-Power PoE Controller/Converter Copyright © 2012, Texas Instruments Incorporated SLVA475 – January 2012 Submit Documentation Feedback Performance Data and Typical Characteristic Curves www.ti.com The following scope plot shows the 5-V output voltage start-up waveform after the application of 48-Vdc at J2 (PoE). The output was loaded to 5 A. VOUT Figure 9. Enable Turnon Waveform – Output Fully Loaded SLVA475 – January 2012 Submit Documentation Feedback Efficiency-Optimized, Synchronous Flyback, High-Power PoE Controller/Converter Copyright © 2012, Texas Instruments Incorporated 9 PMP6672B Assembly Drawing and PCB Layout 5 www.ti.com PMP6672B Assembly Drawing and PCB Layout Figure 10 and Figure 11 show the design of the PMP6672B printed-circuit board. Note that the same circuit board used on TPS23754EVM-420 (SLVU301) is used for PMP6672B. Figure 10. Top-Side Layout 10 Figure 11. Bottom-Side Layout Efficiency-Optimized, Synchronous Flyback, High-Power PoE Controller/Converter Copyright © 2012, Texas Instruments Incorporated SLVA475 – January 2012 Submit Documentation Feedback Bill of Materials www.ti.com 6 Bill of Materials Table 2. PMP6672B Components List According to the Schematic Shown in Figure 1 Count RefDes Value Description Size Part Number MFR 1 C1 1nF Capacitor, Ceramic, 100V, X7R, 10% 0805 Std Std 1 C100 330pF Capacitor, Ceramic, 100V, X7R, 10% 0603 Std Std 2 C10, C11 1uF Capacitor, Ceramic, 1uF, 100V, X7R, 15% 1210 Std Std 1 C14 10nF Capacitor, Ceramic, 100V, X7R, 10% 0603 Std Std 3 C15, C16, C17 47uF Capacitor, Ceramic, 10V, X5R, 15% 1210 Std Std 2 C18, C19 330uF Capacitor, Aluminum, 6.3V, 20% 0.260 x 0.276 inch EEVFK0J331XP Panasonic 1 C2 0.1uF Capacitor, Ceramic, 100V, X7R, 10% 0805 Std Std 1 C20 1uF Capacitor, Ceramic, 16V, X7R, 15% 0603 Std Std 2 C21, C32 1.0uF Capacitor, Ceramic, 16V, X7R, 10% 0603 Std Std 1 C22 1200pF Capacitor, Ceramic, 50V, X7R, 15% 0603 Std Std 1 C23 1000pF Capacitor, Ceramic, 100V, X7R, 15% 0603 Std Std 1 C24 2200pF Capacitor, Ceramic, 2KV, X7R, 15% 1812 Std Std 1 C25 1.0uF Capacitor, Ceramic, 25V, X7R, 10% 0805 Std Std 1 C26 22uF Capacitor, Aluminum, 25V, 20% 5x5.8mm EEVFK1E220R Panasonic 2 C27, C28 0.47uF Capacitor, Ceramic, 16V, X7R, 15% 0603 Std Std 1 C29 3300pF Capacitor, Ceramic, 50V, X7R, 15% 0603 Std Std 4 C3, C4, C5, C6 0.01uF Capacitor, Ceramic, 100V, X7R, 15% 0603 Std Std 1 C30 27nF Capacitor, Ceramic, 50V, X7R, 15% 0603 Std Std 1 C31 6.8nF Capacitor, Ceramic, 50V, X7R, 15% 0603 Std Std 1 C7 1000pF Capacitor, Ceramic, 2kV, X7R, 15% 1210 Std Std 3 C8, C12, C13 0.1uF Capacitor, Ceramic, 100V, X7R, 15% 0805 Std Std 1 C9 47uF Capacitor, Aluminum, 63V, ±20% 0.328 x 0.390 inch EEVFK1J470P Panasonic 1 CL1 NA Current Loop, 0.025 holes 0.120 X 0.075 inch NA NA 1 D1 B2100 Diode, Schottky, 2-A, 100-V SMB B2100-13 Diodes Inc 1 D100 1N4148W-7-F Diode, Signal, 300-mA, 75-V, 350-mW SOD-123 1N4148W-7-F Diodes 2 D14, D18 SMAJ58A Diode, TVS, 58-V, 1W SMA SMAJ58A Diodes Inc. 1 D15 MURS120T3 Diode, UltraFast Rectifier, 1-A, 200-V SMB MURS120T3 On Semi 1 D16 BAV20WS Diode, Small Signal, 250mA, 150V SOD-323 BAV20WS Micro Commercial Components 2 D17, D19 BAV99 Diode, Dual Ultra Fast, Series, 200-mA, 70-V SOT23 BAV99 Fairchild 2 D2, D3 LN1371G Diode, LED, Green, 10-mA, 2.6-mcd 0.114 X 0.049 inch LN1371G Panasonic 1 D4 LN1271RAL Diode, LED, Ultra Bright Red, 10-mA, 5-mcd 0.114 X 0.049 inch LN1271RAL Panasonic 9 D5, D6, D7, D8, D9, D10, D11, D12, D13 B1100 Diode, Schottky, 1A, 100V SMA B1100 Diodes, Inc 4 FB1, FB2, FB3, FB4 500 Bead, Ferrite, 2000mA, 60mΩ 1206 MI1206L501R-10 Steward 2 J1, J2 5520252-4 Connector, Jack, Modular, Rt. Angle,8 POS 0.705 x 0.820 inch 5520252-4 AMP 2 J3, J11 ED1514 Terminal Block, 2-pin, 6-A, 3.5mm 0.27 x 0.25 ED1514 2 J4, J10 PTC36SAAN Header, Male 3-pin, 100mil spacing, (36-pin strip) 0.100 inch x 3 PTC36SAAN Sullins 5 J5, J6, J7, J8, J9 PTC36SAAN Header, Male 2-pin, 100mil spacing, (36-pin strip) 0.100 inch x 2 PTC36SAAN Sullins 1 L1 3.3uH Inductor, SMT, 2.0A, 80-mΩ 4.45x6.6mm DO1608C-332 Coilcraft 1 L2 0.33uH Inductor, SMT, 6.26A, 7.4-mΩ 0.300 sq" DR74-R33 Cooper 1 Q1 SiR422DP MOSFET, NChan, 40V, 50A, 2.8 mΩ PWRPAK S0-8 SiR422DP Vishay-Siliconix 1 Q2 Si7898DP or FDMS2572 MOSFET, NChannel, 150V, 4.8A, 85-mΩ PWRPAK S0-8 or POWER 56 Si7898DP or FDMS2572 Vishay or Fairchild 1 Q3 MMBT3906 Bipolar, PNP, 40V, 200mA, 225mW SOT23 MMBT3906LT1 On Semi 1 R1 100K Resistor, Chip, 1/16W, 1% 0603 Std Std 1 R100 121K Resistor, Chip, 1/16W, 1% 0603 Std Std 1 R12 39K Resistor, Metal Film, 1/4 watt, ± 5% 1206 Std Std 1 R13 24.9k Resistor, Chip, 1/16W, 1% 0603 Std Std 2 R14, R15 69.8K Resistor, Chip, 1/16W, 1% 0603 Std Std 1 R16 10 Resistor, Chip, 1/10W, 1% 0805 Std Std SLVA475 – January 2012 Submit Documentation Feedback Efficiency-Optimized, Synchronous Flyback, High-Power PoE Controller/Converter Copyright © 2012, Texas Instruments Incorporated 11 Bill of Materials www.ti.com Table 2. PMP6672B Components List According to the Schematic Shown in Figure 1 (continued) Count 12 RefDes Value Description Size Part Number MFR 1 R17 22.1k Resistor, Chip, 1/16W, 1% 0603 Std Std 1 R18 10 Resistor, Chip, 1/16W, 5% 0603 Std Std 1 R19 63.4 Resistor, Chip, 1/10W, 1% 0805 Std Std 1 R2 15K Resistor, Chip, 1/4W, 1% 1210 Std Std 1 R20 4.7 Resistor, Chip, 1/16W, 1% 0603 Std Std 1 R21 332 Resistor, Chip, 1/16W, 1% 0603 Std Std 1 R22 0.18 Resistor, Chip, 1/2W, 1% 2010 Std Std 2 R23, R28 10K Resistor, Chip, 1/16W, 1% 0603 Std Std 1 R24 1.5K Resistor, Chip, 1/16W, 1% 0603 Std Std 1 R25 2K Resistor, Chip, 1/16W, 1% 0603 Std Std 1 R26 49.9 Resistor, Chip, 1/16W, 1% 0603 Std Std 1 R27 604 Resistor, Chip, 1/16W, 1% 0603 Std Std 1 R29 41.2K Resistor, Chip, 1/16W, 1% 0603 Std Std 2 R3, R4 1K Resistor, Chip, 1/16W, 1% 0603 Std Std 1 R30 13.7K Resistor, Chip, 1/16W, 1% 0603 Std Std 1 R5 6.49K Resistor, Chip, 1/16W, 1% 0603 Std Std 1 R6 4.02K Resistor, Chip, 1/16W, 1% 0603 Std Std 1 R7 8.87K Resistor, Chip, 1/16W, 1% 0603 Std Std 4 R8, R9, R10, R11 75 Resistor, Chip, 1/16W, 1% 0603 Std Std 1 T1 ETH1-230LD XFMR, Mid-Power PoE Magnetics S0 14 Wide ETH1-230LD Coilcraft 1 T2 JA4456-DL Transformer, SMT For PoE/PD, 25W, 2.8A 0.810 x 1.181 inch JA4456-DL Coilcraft 1 T3 PA0184 XFMR, SMT Gate Drive 0.355 X 0.340 inch PA0184 Pulse 1 U1 FOD817D IC, Optocoupler, 70-V, 300 - 600% CTR SMT-4PDIP FOD817DS Fairchild 1 U2 TPS23754PWP IC, IEEE 802.3at PoE Interface and Isolated Converter Controller PWP20 TPS23754PWP TI 1 U3 TCMT1107 IC, Photocoupler, 3750VRMS, 80-160% CTR MF4 TCMT1107 Vishay 1 U4 TLV431A IC, Shunt Regulator, 6V, 10mA, 1% SOT23-5 TLV431ACDBVR TI 6 — Shunt, Black 100-mil 929950-00 3M 1 — PCB, 5.90 In x 2.03 In x 0.062 In HPA420 Any Efficiency-Optimized, Synchronous Flyback, High-Power PoE Controller/Converter Copyright © 2012, Texas Instruments Incorporated SLVA475 – January 2012 Submit Documentation Feedback IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. 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