DEMO MANUAL DC1561B LTC4278: PoE+ (802.3at) Powered Device Controller and Synchronous Flyback Description Demonstration circuit 1561B is a high power supply, featuring the LTC®4278. This board is a Type 2 (IEEE 802.3at) compliant, high power Power over Ethernet (PoE), Powered Device (PD). The DC1561B also features a wide auxiliary input voltage range of 9V to 57V. The demonstration board can connect to a Type 2 Power Sourcing Equipment (PSE) device, such as the DC1567. power, small power supply that utilizes a highly-efficient isolated flyback topology with synchronous rectification. The DC1561B outputs 5V at 4.5A. The LTC4278 provides IEEE 802.3at standard (PoE+) PD interfacing and power supply control. When the PD fully powers, the PD interface passes power from the PSE to the switcher through an internal, low resistance, high power MOSFET. The highly integrated LTC4278 controls a high Design files for this circuit board are available at http://www.linear.com/demo Performance Summary PARAMETER DC1561B also demonstrates the use of an auxiliary wall adapter for nominal 12VDC, 24VAC/24VDC, or 48VDC systems. When present, the auxiliary supply is the dominant supply over PoE to provide power. L, LT, LTC, LTM, µModule, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. (TA = 25°C) CONDITION VALUE PoE Input Voltage (VPORT) At RJ–45 Jack (J1) 37V to 57V Auxiliary Input Voltage (VAUX) From AUX+ to AUX – Terminals 8V(On)/7V(Off) to 57V Output Voltage (VOUT) Typical 5V Output Current (IOUT) Over 9V to 57V Input Voltage 4.5A (Max) Output Voltage Ripple (Typ) Over 9V to 57V Input Voltage, IOUT = 4.5A 30mVP–P (Typ) Output Regulation PoE Input Voltage, IOUT = 0A to 4.5A Auxiliary Input Voltage, IOUT = 0A to 4.5A ±0.4% (Typ) ±1.1% (Typ) Output Voltage Response to Load Step (Typ) Load Step = 2.25A to 4.5A, 48V Input Voltage ±500mV (±10%) (Typ) Settling Time (Within 1% of VOUT) < 150µs (Typ) Switching Frequency Efficiency 250kHz (Typ) VAUX = 24V, IOUT = 4.5A (Includes Diode D12) 89% (Typ) dc1561bf 1 DEMO MANUAL DC1561B Operating Principles A compatible high power PSE board, such as the DC1567, connects to the DC1561B at the RJ45 connector J1 (see the schematic in Figure 12). As required by IEEE 802.3at, the DC1561B uses a diode bridge across the data pairs and signal pairs. Schottky diodes (D2-D9) are used at the input to improve efficiency over standard diode bridges. The LTC4278 provides the PoE required 25k signature resistance and classification up to class 4 (25.5W). When the PD is powered and voltage reaches above the PoE “On Voltage,” the LTC4278 switches the port voltage over to the power supply controller through its internal MOSFET. This voltage allows the Zener and NPN-based linear regulator (R9/D17/Q3) to power up the bias pin, VCC, of the power supply controller. The IC begins a controlled soft-start of the output. As the output voltage rises, bias power takes over by the bias supply made up of T1’s bias winding and D11 since it reverse biases the linear regulator’s (Q3) base to emitter junction. When the soft-start period is over, the output voltage regulates by observing the pulses across the bias winding during the flyback time. The Primary Gate drive (PG) and Synchronous Gate (SG) drive Pulse Width Modulates (PWM) in order to keep the output voltage constant. The synchronous gate drive signal transmits to the secondary via the small signal transformer, T2. The output of T2 drives a discrete gate drive buffer, R22 and Q6/7 to achieve fast gate transition times, hence higher efficiency. The two-stage input filter, C5, L2, and C6 and output filter, C1/C3, L1, and C9 are the reasons that this PoE flyback supply has exceptionally low differential mode conducted emissions. A common mode filter consisting of a common mode choke (L3) and common mode capacitor (C34) yields low common mode emissions out of the power supply. Quick Start Procedure Demonstration circuit 1561B is easy to set up to evaluate the performance of the LTC4278 in a PoE+ PD application. Refer to Figure 1 for proper equipment setup and follow the procedure below: 1. Place test equipment (voltmeter, ammeter, and electronic load) across output. 2.Input supplies: a. Connect a PoE+ capable PSE, like the DC1567, with an Ethernet cable to the RJ45 connector, J1. See Figure 1. b.Or, connect a 37V to 57V capable power supply (Power Supply in Figure 1) across VPORT_P and VPORT_N. 3.Check for the proper output voltage of 5V. 4. Once the proper output voltage is confirmed, adjust the output’s load current within the operating range and observe the output voltage regulation, output ripple voltage, efficiency, and other parameters. NOTE: When measuring the input or output voltage ripple, care must be taken to avoid a long ground lead on the oscilloscope probe. Measure the output (or input) voltage ripple by touching the probe tip and probe ground directly across the +VOUT and –VOUT (or VPORT_P and VPORT_N) terminals. See Figure 2 for proper scope probe technique. c.Or, if evaluating the auxiliary power supply capability, connect a 9V to 57V at 4A capable power supply across AUX+ to AUX– (Auxiliary Supply in Figure 1). dc1561bf 2 DEMO MANUAL DC1561B quick start procedure Figure 1. Proper Measurement Equipment Setup GND VIN Figure 2. Measuring Input and Output Ripple dc1561bf 3 DEMO MANUAL DC1561B Measured Data 92 5.25 90 5.20 88 5.15 86 5.10 84 5.05 82 5.00 80 4.95 78 76 74 9VAUX 24VAUX 42VAUX 57VAUX VOUT (V) EFFICIENCY (%) Figures 3 through 11 are measured data for a typical DC1561B. Figure 12 is the schematic and Figure 13 is the bill of materials. 4.90 4.85 4.80 72 4.75 5.0E2 9.4E2 1.4E3 1.8E3 2.3E3 2.7E3 3.2E3 3.6E3 4.1E3 4.5E3 LOAD CURRENT (mA) DC1561B F03 Figure 3. Efficiency and Regulation (Including OR’ing Diode, D12) dc1561bf 4 DEMO MANUAL DC1561B Measured Data Figure 4. Output Ripple (24VAUX, 4.5A) Figure 5. Load Transient Response (57VPORT, 2.25A to 4.5A to 2.25A) dc1561bf 5 DEMO MANUAL DC1561B Measured Data Figure 6. Temperature Data (9VAUX, 4.5A, Top) Figure 7. Temperature Data (9VAUX, 4.5A, Bottom) dc1561bf 6 DEMO MANUAL DC1561B Measured Data Figure 8. Temperature Data (37VPORT, 4.5A, Top) Figure 9. Temperature Data (37VPORT, 4.5A, Bottom) dc1561bf 7 DEMO MANUAL DC1561B Measured Data Figure 10. Stresses (9VAUX, 4.5A) Figure 11. Stresses (57VAUX, 4.5A) dc1561bf 8 DEMO MANUAL DC1561B Parts List QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components (Note 1) 2 C1, C3 CAP., X5R, 22µF, 6.3V, 1206 MURATA, GRM31CR60J226KE19L 2 C6, C2 CAP., X7S, 3.3µF, 100V, 1210 TDK, C3225X7S2A335M 1 C4 CAP., X7R, 1000pF, 50V, 1206 AVX, 12065C102KAT 1 C5 CAP., ELEC., 10µF, 100V NIC COMP., NACEW100M100V6.3X8TR13F 1 C7 CAP., NPO, 220pF, 200V, 1206 AVX, 12062A221KAT2A 1 C8 CAP., X7R, 0.1µF, 100V, 0805 AVX, 08051C104JAT2A 1 C9 CAP., X5R, 100µF, 6.3V, 1210 TDK, C3225X5R0J107M 3 C19, C24, C27 CAP., X7R, 1µF, 16V, 0805 MURATA, GRM21BR71C105KA01L 1 C25 CAP., X7R, 1000pF, 50V, 0603 AVX, 06035C102KAT2A 1 C26 CAP., X7R, 33nF, 50V, 0603 AVX, 06035C333KAT2A 1 C28 CAP., X7R, 2200pF, 50V, 0603 AVX, 06035C222KAT2A 1 C30 CAP., NPO, 33pF, 50V, 0603 AVX, 06035A330KAT2A 1 C32 CAP., X7R, 0.1µF, 50V, 0603 AVX, 06035C104KAT2A 1 C33 CAP., X7R, 3300pF, 50V, 0603 AVX, 06035C332KAT2A 1 C34 CAP., X7R, 4700pF, 2KV, 1812 MURATA, GR443DR73D472KW01L 1 D1 DIODE, 58V 600W TVS, SMB-DIODE DIODES/ZETEX, SMBJ58A-13-F 1 D16 DIODE, SCHOTTKY, 1A, SMA-DIODE DIODES/ZETEX, B1100-13-F 1 D11 DIODE, FAST SWITCHING, SOT23 DIODES/ZETEX, BAS21-7-F 1 D12 DIODE, SCHOTTKY, 5A DIODES/ZETEX, PDS5100H-13 1 D13 DIODE, 1A SM RECTIFIER DIODES/ZETEX, S1B-13-F 1 D14 DIODE, SCHOTTKY, SOT23 DIODES/ZETEX, BAT54-7-F 1 D17 DIODE, SMT ZENER 7.5V, 500mW CENTRAL SEMI., CMHZ4693 TR 1 L1 INDUCTOR, 180µH, DO1813H-181MLD COILCRAFT, DO1813H-181MLD 1 L2 INDUCTOR, 8.2µH, WE-HCC WÜRTH, 7443330820 1 Q1 MOSFET, N-CHANNEL, 100V, Power 56 FAIRCHILD, FDMS86101 1 Q2 MOSFET, N-CHANNEL, 40V, LFPAK RENESAS, HAT2169H 1 Q3 TRANSISTOR, NPN, SOT23 DIODES/ZETEX, FMMT624TA 1 Q5 TRANSISTOR, PNP, SOT23 ON SEMI., BSS63LT1G 1 Q6 TRANSISTOR, PNP, SOT23 CENTRAL SEMI., CMLT7820G TR 1 Q7 TRANSISTOR, NPN, SOT23 CENTRAL SEMI., CMLT3820G TR 1 R28 RES., CHIP, 10k, 1/10W, 1%, 0603 VISHAY, CRCW060310K0FKEA 1 R2 RES., CHIP, 47Ω, 1/4W, 5%, 1206 VISHAY, CRCW120647R0JNEA 1 R9 RES., CHIP, 20k, 1/4W, 5%, 1206 VISHAY, CRCW120620K0JNEA 1 R10 RES., CHIP, 20Ω, 1/8W, 5%, 0805 VISHAY, CRCW080520R0JNEA 1 R12 RES., CHIP, 294k, 1/10W, 1%, 0603 VISHAY, CRCW0603294KFKEA 1 R13 RES., CHIP, 21.5k, 1/10W, 1%,0603 VISHAY, CRCW060321K5FKEA 1 R14 RES., CHIP, 2.49k, 1/10W, 1%, 0603 VISHAY, CRCW06032K49FKEA 1 R15 RES., CHIP, 10Ω, 1/10W, 1%, 0603 VISHAY, CRCW060310RFKEA 1 R16 RES., CHIP, 0.012Ω, 1/4W, 1%, 1206 VISHAY, WSL1206R0120FEA 1 R17 RES., CHIP, 100Ω, 1/10W, 1%, 0603 VISHAY, CRCW0603100RFKEA dc1561bf 9 DEMO MANUAL DC1561B parts list QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER 1 R18 RES., CHIP, 20k, 1/10W, 1%, 0603 VISHAY, CRCW060320K0FKEA 1 R19 RES., CHIP, 54.9k, 1/10W, 1%, 0603 VISHAY, CRCW060354K9FKEA 1 R20 RES., CHIP, 3.01k, 1/10W, 1%, 0603 VISHAY, CRCW06033K01FKEA 1 R21 RES., CHIP, 24k, 1/10W, 5%, 0603 VISHAY, CRCW060324K0JNEA 1 R22 RES., CHIP, 15Ω, 1/10W, 5%, 0603 VISHAY, CRCW060315R0JNEA 1 R23 RES., CHIP, 12k, 1/10W, 5%, 0603 VISHAY, CRCW060312K0JKEA 1 R24 RES., CHIP, 100k, 1/10W, 1%, 0603 VISHAY, CRCW0603100KFKEA 1 R25 RES., CHIP, 1.82k, 1/10W, 1%, 0603 VISHAY, CRCW06031K82FKEA 1 R26 RES., CHIP, 38.3k, 1/10W, 1%, 0603 VISHAY, CRCW060338K3FKEA 1 R27 RES., CHIP, 3.3k, 1/10W, 1%, 0603 VISHAY, CRCW06033K30FKEA 1 R34 RES., CHIP, 5.1Ω, 1/4W, 5%, 1206 VISHAY, CRCW12065R10JNEA 1 R36 RES., CHIP, 30.9Ω, 1/10W, 1%, 0603 VISHAY, CRCW060330R9FKEA 1 T1 Flyback Transformer EPC3472G-LF PCA Electronics Inc., EPC3472G-LF 1 T2 XFMR, GATE DRIVE, EPA4271GE PCA, EPA4271GE-LF 0 T2 (ALTERNATE) XFMR, GATE DRIVE PULSE, PE-68386NL 0 T2 (ALTERNATE) XFMR, GATE DRIVE EPCOS, T5476 1 U1 IC, LTC4278IDKD, DFN32 LINEAR TECH., LTC4278IDKD Additional Demo Board Circuit Components (Note 2) 0 C10 OPT CAP., TANT, 100µF, 6.3V, 3528 NEO CAPACITOR, PSLB20J107M(25) 0 C11, C12, C13 (OPT) CAP., 1812, OPT 0 C31 (OPT) CAP., 0603 1 C99 CAP., X7R, 1000pF, 50V, 0603 AVX, 06035C102KAT2A 8 D2-D9 DIODE, SCHOTTKY, 1A, SMA-DIODE DIODES/ZETEX, B1100-13-F 1 D15 LED, SMT GREEN PANASONIC, LN1351C-(TR) 14 E1-E14 TP, TURRET, 0.094" MILL-MAX, 2501-2-00-80-00-00-07-0 1 J1 CONN., Integrated Jack WÜRTH, 7499511001 1 L3 INDUCTOR, 3.3mH, 744272332 WÜRTH, 744272332 2 R1, R8 RES., CHIP, 10k, 1/10W, 1%, 0603 VISHAY, CRCW060310K0FKEA 2 R11, R38 RES., CHIP, 0Ω, JUMPER, 0603 VISHAY, CRCW06030000Z0EA 0 R3, R37 (OPT) RES., 1206 1 R33 RES., CHIP, 620, 1/10W, 1%, 0603 VISHAY, CRCW0603620RFKEA 1 U2 I.C., OPTOCOUPLERS PS2801-1-L NEC, PS2801-1-F3-A Note 1: Required Circuit Components are those parts that are required to implement the core circuit function. Note 2: Additional Demo Board Circuit Components are those parts that provide added functionality for the demo board but are or may not be required in the actual circuit. Some of these parts, like the Ethernet transformer (T3), can be substituted with other vendor’s parts. dc1561bf 10 DEMO MANUAL DC1561B Schematic Diagram dc1561bf Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights. 11 DEMO MANUAL DC1561B DEMONSTRATION BOARD IMPORTANT NOTICE Linear Technology Corporation (LTC) provides the enclosed product(s) under the following AS IS conditions: This demonstration board (DEMO BOARD) kit being sold or provided by Linear Technology is intended for use for ENGINEERING DEVELOPMENT OR EVALUATION PURPOSES ONLY and is not provided by LTC for commercial use. As such, the DEMO BOARD herein may not be complete in terms of required design-, marketing-, and/or manufacturing-related protective considerations, including but not limited to product safety measures typically found in finished commercial goods. As a prototype, this product does not fall within the scope of the European Union directive on electromagnetic compatibility and therefore may or may not meet the technical requirements of the directive, or other regulations. If this evaluation kit does not meet the specifications recited in the DEMO BOARD manual the kit may be returned within 30 days from the date of delivery for a full refund. THE FOREGOING WARRANTY IS THE EXCLUSIVE WARRANTY MADE BY THE SELLER TO BUYER AND IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE. EXCEPT TO THE EXTENT OF THIS INDEMNITY, NEITHER PARTY SHALL BE LIABLE TO THE OTHER FOR ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES. The user assumes all responsibility and liability for proper and safe handling of the goods. Further, the user releases LTC from all claims arising from the handling or use of the goods. Due to the open construction of the product, it is the user’s responsibility to take any and all appropriate precautions with regard to electrostatic discharge. Also be aware that the products herein may not be regulatory compliant or agency certified (FCC, UL, CE, etc.). No License is granted under any patent right or other intellectual property whatsoever. LTC assumes no liability for applications assistance, customer product design, software performance, or infringement of patents or any other intellectual property rights of any kind. LTC currently services a variety of customers for products around the world, and therefore this transaction is not exclusive. Please read the DEMO BOARD manual prior to handling the product. Persons handling this product must have electronics training and observe good laboratory practice standards. Common sense is encouraged. This notice contains important safety information about temperatures and voltages. For further safety concerns, please contact a LTC application engineer. Mailing Address: Linear Technology 1630 McCarthy Blvd. Milpitas, CA 95035 Copyright © 2004, Linear Technology Corporation dc1561bf 12 Linear Technology Corporation LT 0612 • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 2012