DEMO MANUAL DC1342B LT3758AEMSE High Efficiency SEPIC Converter Description Demonstration circuit 1342B features the LT®3758AEMSE in a 300kHz SEPIC converter circuit, designed for a 24V output from a 18V to 72V input. lockout, adjustable frequency and clock synchronization in a small 10-lead MSOP package or a 3mm × 3mm QFN package. The LT3758A operates over an input range of 5.5V to 100V, suitable for automotive, telecom and industrial applications. It also exhibits a low shutdown current of 1µA, making it ideal for battery-operated systems. Thanks to a novel FBX pin architecture, the LT3758A can be connected directly to a resistor divider from either a positive output voltage or a negative output voltage to ground. It also packs many popular features such as soft-start, input undervoltage The LT3758A 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 1342B. Performance Summary PARAMETER Input Supply Range Output Voltage Design files for this circuit board are available at http://www.linear.com/demo 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. 300kHz SEPIC Regulator. Specifications are at TA = 25°C CONDITIONS MIN TYP MAX 72 V 24 24.72 V 18 23.28 Maximum Output Current Switching Frequency 1 300 UNITS A kHz dc1342bf 1 DEMO MANUAL DC1342B Quick Start Procedure Demonstration circuit 1342B is easy to set up to evaluate the performance of the LT3758AEMSE. Refer to Figure 1 for proper measurement equipment setup and follow the procedure below: 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 input or output voltage ripple by touching the probe tip directly across the VIN or VOUT and GND terminals. See Figure 2 for proper scope probe technique. 1.Place JP1 on the ON position. 3.Turn on the power at the input. NOTE. Make sure that the input voltage does not exceed the maximum input voltage. 4.Check for the proper output voltages. NOTE. If there is no output, temporarily disconnect the load to make sure that the load is not set too high. Once the proper output voltages are established, adjust the loads within the operating range and observe the output voltage regulation, ripple voltage, efficiency and other parameters. 2.With power off, connect the input power supply to VIN and GND. 2 dc1342bf DEMO MANUAL DC1342B Quick Start Procedure + + POWER SUPPLY – – IIN + VIN – + + – – IOUT VOUT + LOAD – 1342B F01 Figure 1. Proper Measurement Equipment Setup VIN GND OR VOUT Figure 2. Measuring Input or Output Ripple dc1342bf 3 DEMO MANUAL DC1342B Parts List ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components 1 1 C1 CAP., X7R, 2.2µF, 100V, 10% 1812 TDK, C4532X7R2A225K 2 2 C3, C4 CAP., TANT, 22µF, 35V, 20% 7343 AVX, TPSD226M035R0125 3 1 C5 CAP., X7R, 3.3µF, 25V, 20% 1210 Taiyo Yuden, TMK325BJ335MN 4 1 C7 CAP., X7R, 4.7µF, 100V, 20% 2220 TDK, C5750X7R2A475M 5 1 C10 CAP., X5R, 4.7µF, 10V, 20% 0805 Taiyo Yuden, LMK212BJ475MG-T 6 1 C11 CAP., X7R, 4.7nF, 50V, 10% 0603 TDK, C1608X7R1H472K 7 1 C12 CAP., C0G, 100pF, 50V, 5% 0603 TDK, C1608C0G1H101J 8 1 C13 CAP., X7R, 0.1µF, 25V, 10% 0603 TDK, C1608X7R1E104K 9 1 D1 Diodes Inc., PDS3100-13 Diodes Inc., PDS3100-13 10 1 L1 IND., Dual, 47µH Würth Elektronik, 744870470 11 1 Q1 N-MOSFET, FDMS2572, Power 56 FAIRCHILD, FDMS2572 12 1 R1 RES., CHIP, 280k, 1/10W, 1% 0603 VISHAY, CRCW0603280KFKEA 13 2 R2, R4 RES., CHIP, 20.0k, 1/10W, 1% 0603 VISHAY, CRCW060320K0FKEA 14 1 R3 RES., CHIP, 232k, 1/10W, 1% 0603 VISHAY, CRCW0603232KFKEA 15 1 R5 RES., CHIP, 0.02, 1W, 1%, 0815 THIN FILM, RL3720WTR02F-C 16 1 R6 RES., CHIP, 30.9k, 1/10W, 1% 0603 VISHAY, CRCW060330K9FKEA 17 1 R7 RES., CHIP, 42.2k, 1/10W, 1% 0603 VISHAY, CRCW060342K2FKEA 18 1 R8 RES., CHIP, 10k, 1/10W, 5% 0603 VISHAY, CRCW060310K0JNEA 19 1 U1 I.C. LT3758AEMSE, MSOP10/Exposed Pad LINEAR TECH.,LT3758AEMSE#TRPBF Additional Demo Board Circuit Components 1 1 CIN1 CAP., Alum., 10µF, 100V, E Size Code Hardware: For Demo Board Only 1 7 E1, E2, E3, E4, E5, E6, E7 TESTPOINT, TURRET, .094" PBF MILL-MAX, 2501-2-00-80-00-00-07-0 2 1 JP1 3 PIN, 0.079 SINGLE ROW HEADER SAMTEC, TMM103-02-L-S 3 1 XJP1 SHUNT, .079" CENTER SAMTEC, 2SN-BK-G 4 dc1342bf GND SYNC VCC E7 E6 JP1 RUN E5 OFF ON 1 2 R8 10K 3 C12 100pF C11 4.7nF R6 30.9K R4 0.1uF R7 42.2K C13 20K 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. 3 5 4 2 1 9 SENSE GATE INTVcc VIN 6 7 8 10 SS SYNC RT FBX VC SHDN/UVLO U1 LT3758AEMSE 4 R5 0.02 1W Thursday, February 28, 2013 APPROVED 2/28/13 2/28/13 DATE SCALE: + C4 22uF 35V E4 E3 E2 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 Fax: (408)434-0507 C5 3.3uF 25V LT3758AEMSE TECHNOLOGY + C3 22uF 35V + CIN1 10uF 100V FILENAME: DWG NO SHEET 1 DC1342B High Efficiency SEPIC Converter R2 20.0K 1% R1 280K 1% SIZE CAGE CODE TITLE 2 PDS3100 4.7uF 100V L1-2 Q1 47uH FDMS2572 D1 4 C1 2.2uF 100V C7 L1-1 47uH CONTRACT NO. C10 4.7uF 10V 3 1 APPROVALS DRAWN J. Wu ENGINEER W. Gu CHECKED R3 232K GND 11 5 6 7 8 1 2 3 E1 OF GND 1 1 REV VOUT 24V @ 1.0A GND VIN 18V - 72V DEMO MANUAL DC1342B Schematic Diagram dc1342bf 5 DEMO MANUAL DC1342B 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 6 dc1342bf Linear Technology Corporation LT 0413 • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 2013