DEMO MANUAL DC1860B LT3748 No-Opto Isolated FlybacK Converter for PSE Applications Description

Transcription

1 DEMO MANUAL DC860B LT748 No-Opto Isolated FlybacK Converter for PSE Applications Description Demonstration circuit 860B is an isolated flyback converter featuring the LT748. This demo circuit is designed for Power Sourcing Equipment (PSE) applications with a 5.5V output from a 0V to 5V DC input, with nominal input voltage of V. The output current is from 0mA to 700mA, and is capable of a maximum short period overload current of 900mA. Table summarizes the performance of the demo board. This demo circuit can also be easily modified for different PSE applications with some predesigned transformers. The LT748 is a high input voltage isolated flyback controller operating with input supply voltages from 5V to 00V, and.9a average gate drive source and sink current. The LT748 utilizes boundary mode operation to provide a high efficiency, small size solution with improved regulation. The part senses the isolated output voltage directly from the primary side flyback waveform during the off time of the power switch. No third winding, opto-coupler, or signal transformer is required for regulation. The LT748 data sheet gives a complete description of the part, operation and application information. The data sheet must be read in conjunction with this quick start guide for demo circuit 860B. Design files for this circuit board are available at L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. PERFORMANCE SUMMARY (T A = 5 C) PARAMETER CONDITIONS MIN TYP MAX UNITS Input Voltage Range 0 5 V Output Voltage V IN = 0V 5V V I OUT = 0V 700 ma Maximum Output Current V IN = 0V 5V 700 ma Minimum Output Current V IN = 0V 5V 0 ma Output Voltage Ripple (Peak to Peak) V IN = 0V 5V, I OUT = 0 700mA 50 mv Efficiency V IN =.V, I OUT = 700mA 87.8 %

2 DEMO MANUAL DC860B quick start procedure Demo circuit 860B is easy to set up to evaluate the performance of the LT748. Refer to Figure for proper equipment setup and follow the procedure below.. With power off, connect the input power supply to the board through V IN (E) and GND (E) terminals.. Connect the load to the terminals V + OUT (E6) and V OUT (E7) on the board.. Turn on the power at the input. Increase V IN slowly to 0V. NOTE: Make sure that the input voltage does not exceed 5V. If higher operating voltage is required, power components with higher voltage ratings should be used. 4. Check for the proper output voltages. The output should be regulated at 5.5V (±5%). NOTE: The LT748 requires minimum load to maintain good output voltage regulation. A zener diode D together with preload resistors R, R4, R5 and R6 are placed in the output to clamp the output voltage to ~5.5V without ex-board preload requirement. The efficiency is higher than 90% without the preload resistors, but the output may exceed 57V under no load or transient condition. 5. Once the proper output voltage is established, adjust the input voltage and load current within the operating range and observe the output voltage regulation, ripple voltage, efficiency and other parameters. NOTE: When measuring the input or output voltage ripples, care must be taken to avoid a long ground lead on the oscilloscope probe. Measure the input or output voltage ripple by touching the probe tip directly across the terminals of the input or output capacitor. See Figure for proper scope probe technique. NOTE: A gate resistor of less than 0Ω can be added to the demo circuit to slow down the turning off of the switch, and reduce the switching node voltage spike. A RC snubber can be added as well to the primary winding of the transformer to damp the spike and reduce the EMI.

3 DEMO MANUAL DC860B quick start procedure Figure. Proper Measurement Equipment Setup + C OUT V OUT GND dc860b F0 Figure. Proper Scope Probe Placement for Measuring Input or Output Ripple

4 DEMO MANUAL DC860B quick start procedure EFFICIENCY (%) V IN = 0V V IN =.V V IN = 5V LOAD CURRENT (ma) dc860b F0 Figure. Typical Efficiency Curve, (T A = 5 C) Output Voltage (V) V IN = 5V V IN = 0V LOAD CURRENT (ma) dc860b F04 Figure 4. Load Regulation V OUT : 0V/DIV V DS : 0V/DIV 4 Figure 5. Recovery from Short Circuit Fault

5 DEMO MANUAL DC860B parts list ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components C, C Cap., X5R, µf, 6V, 0%, 0 Taiyo Yuden EMK5BJ6MN C5 Cap., X7S, 0.µF, 00V, 0%, 0805 TDK C0X7SA4KT C6, C7, C8 Cap., X7S, 4.7µF, 00V, 0%, 8 TDK C45X7SA475MT 4 C9 Cap., Elect. 470µF, 6V, 0%, J6-PANASONIC PANASONIC EEVFKJ47M 5 C0 Cap., X5R, 4.7µF, 6V, 0%, 0805 Taiyo Yuden EMKBJ475MG 6 C Cap., X5R, 0.µF, 0V, 0%, 060 AVX 060ZD4MATA 7 C Cap., NPO, 470pF, 5V, 0%, 060 AVX 060A47KATA 8 C Cap., Ceramic.nF, 50V, 0%, 8 Murata GA4QR7GDKW0L 9 C4, C5 Cap,, X7R, 6800pF, 5V, 0%, 060 AVX 060C68MATA 0 D Diode Zener 6V ON Semi. SMB594BT D Schottky Diode A/00V, PowerDItm Diodes Inc. DFLS00 D Schottky Diode A, PowerDi5 Diodes Inc. PDS00- L Inductor,.8µH Würth Electronik Q Mosfet N-Channel, 00V, LFPAK Renesas HAT7H-EL-E 5 R, R Res., Chip, 6k, 0.5W, 5%, 06 Vishay CRCW066K0JNED 6 4 R, R4, R5, R6 Res., Chip,.8k, 0.5W,, 06 Vishay CRCW06K8FKEA 7 R, R7 Res/Jumper, Chip, 0Ω, /6W, AMP 060 Vishay CRCW Z0EA 8 R4 Res., Chip, 00k, 0.06W,, 060 Vishay CRCW06000KFKEA 9 R5 Res., Chip, 6k, 0.06W, 5%, 060 Vishay CRCW0606K0JNEA 0 R6 Res., Chip, 8.5k, 0.06W,, 060 Vishay CRCW0608K5FKEA R8 Res., Chip,, 0.06W, 5%, 060 Vishay CRCW060R0JNEA R9 Res., Chip, 70k, 0.06W, 5%, 060 Vishay CRCW06070KJNEA R0 Res., Chip, 40.k, 0.06W,, 060 Vishay CRCW06040KFKEA 4 R Res., Chip, 6.04k, 0.06W,, 060 Vishay CRCW0606K04FKEA 5 R Res., 0.005, 0.5W,, 06 Vishay Dale WSL-06-5L000-6 T Transformer, XFMR Würth Elektronik U I.C., LT748EMS Linear Tech. Corp. LT748EMS Hardware For Demo Board Only E, E Connector, Banana Jack Keystone E5, E6, E7 Turret, Testpoint Mill Max JP Headers, Sgl. Row, Pins, mm Ctrs. Samtec TMM-0-0-L-S 4 4 MH, MH, MH, MH4 STAND-OFF, NYLON 0.5" tall KEYSTONE, 88(SNAP ON) 5 XJP Shunt, mm Ctrs. Samtec SN-BK-G 6 FAB, 860B, Rev.PCB DEMO CIRCUIT 860B 7 STENCILS - TOP & BOTTOM STENCIL DC860B Additional Demo Board Circuit Components 0 C Cap., Alum 0µ,F 5V, 0%, 5cv0gX SANYO 5CV0gX 0 C6 Cap., Alum. Elect. 00µF, 6V, ±0%, NipponChemi-Con/JA0 Nippon Chemi-Con EMZA60ADA0MJA0G 0 L Inductor, 47µH, IHLP4040 VISHAY IHLP-4040DZ-ER-470-M 4 0 T Transformer, XFMR Würth Elektronik T Transformer, XFMR Würth Elektronik E, E4 Turret, Testpoint Mill Max

6 A A + B B E E DEMO MANUAL DC860B Schematic Diagram 6 C D REVISION HISTORY ECO REV DESCRIPTION APPROVED DATE PRODUCTION ZHONGMING Y. Oct 0, VOPT E VOPT+ [email protected] L VIN.8uH SW T VOUT+ VIN E 7 4 Wurth Electronik E6 VOUT+ 0V-5V [email protected] C C C R R4 R5 R6 0uF uf uf C5 R C6 C7 C8.8k.8k.8k + E 5V 6V 6V 0.uF R 0.8k 6k 4.7uF 4.7uF 4.7uF 470uF SANYO V 6k 06 00V 00V 00V V GND E7 VOUT- 5 D 9 SMB594BT E4 E5 DIODE D VOPT- EXT_EN R SHDN R4 00k 0 Ohm PDS00- RUN VIN D EN/UVLO INTVCC 5 C0 4.7uF DFLS00 SHDN U 6V R JP 6k LT748EMS R6 RFB 6 8.5k 0 Q SS 6 R7 HAT7H-EL-E TC GATE 6 0 Ohm Renesas C 0.uF 4 VC 7 R8 REF SENSE 7 R9 C R0 GND GND 70k 470pF 40.k C4 R C R pF k 06.nF C5 50V 6800pF 8 CUSTOMER NOTICE APPROVALS LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; TECHNOLOGY HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO PCB DES. VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APPLICATION. COMPONENT SUBSTITUTION AND PRINTED APP ENG. ZHONGMING Y. TITLE: SCHEMATIC CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. SIZE IC NO. REV. C:\PADS PROJECTS\860B\REV_B(09-7-)\SCH\860B_REV.DSN SHEET OF DATE: THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. SCALE = NONE D C

7 DEMO MANUAL DC860B Schematic Diagram A B C D E DIODE T VIN VOPT SW 9 0 VOPT VOUT+ L C6 00uF 6V 47uH IHLP-4040DZ-ER-470-M VISHAY T 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 Optional Circuit APPROVALS CUSTOMER NOTICE LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; TECHNOLOGY HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO PCB DES. VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APPLICATION. COMPONENT SUBSTITUTION AND PRINTED APP ENG. ZHONGMING Y. TITLE: SCHEMATIC CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. IC NO. REV. SIZE C:\PADS PROJECTS\860B\REV_B(09-7-)\SCH\860B_REV.DSN SHEET OF DATE: THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. SCALE = NONE E D C B A 7

8 DEMO MANUAL DC860B 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 0 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 60 McCarthy Blvd. Milpitas, CA 9505 Copyright 004, Linear Technology Corporation 8 LT 0 REV A PRINTED IN USA Linear Technology Corporation 60 McCarthy Blvd., Milpitas, CA (408) FAX: (408) LINEAR TECHNOLOGY CORPORATION 0