DEMO MANUAL DC1661A LT3579/LT3579-1: Boost/Inverting DC/DC Converter DESCRIPTION Demonstration circuit 1661A features the LT®3579 and LT3579-1 in a parallel boost regulator configuration. The circuit is designed to convert a 5V to 10V input source to 12V at 3.5A. DC1661A is designed to survive output short circuit events with an external disconnect MOSFET at the output as default. The circuit board includes an option to install the disconnect MOSFET at the input side. To use it, install Q1 and R2 on the back of the board, place a jumper from Q2 source to drain and cut top copper as shown in Figure 3. The circuit board can also be used to supply two separate output voltages. Cut trace as shown in Figure 3 remove R13 and R14, and set feedback and VC components as needed. The LT3579 includes a 42V master and slave switch combination with 6A total current and can be PERFORMANCE SUMMARY SYMBOL PARAMETER VIN Input Supply Range VOUT Output Voltage Accuracy used in many configurations such as boost, SEPIC, cuk and flyback. It has a 2.5V to 16V operating input range, UVLO, soft-start, programmable switching frequency and many other popular features. The LT3579 data sheet gives a complete description of the part, its operation and application information. The data sheet must be read in conjunction with this quick start guide for working on or modifying the demo circuit 1661A. 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. (TA = 25°C) CONDITIONS MIN VIN = 5V to 10V, ILOAD = 3.5A 11.60 TYP MAX 10 V 12 12.30 V 5 UNITS Efficiency VIN = 5V, ILOAD = 3.5A 83 % Efficiency VIN = 10V, ILOAD = 3.5A 92 % Ripple VIN = 5V, ILOAD = 3.5A 50 mV 1 MHz FS Switching Frequency dc1661af 1 DEMO MANUAL DC1661A QUICK START PROCEDURE Demonstration circuit 1661A is easy to set up to evaluate the performance of the LT3579/LT3579-1. Refer to Figure 1 and Figure 2 for proper measurement equipment set-up and follow the procedure below: To measure 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. Apply 7.5V to input (source must have >12A capability). 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 voltage is established, adjust the load within the operating range and observe the output voltage regulation, ripple voltage, efficiency and other parameters. 1. Place jumper in the following position: JP1 On 2. With power off, connect the input power supply to VIN and GND. dc1661a F01 Figure 1. DC1661A Proper Equipment Set-Up dc1661af 2 DEMO MANUAL DC1661A QUICK START PROCEDURE VOUT GND dc1661 F02 Figure 2. Proper Input/Output Ripple Measurement Technique CUT COPPER HERE TO USE DISCONNECT MOSFET AT INPUT SIDE CUT COPPER HERE FOR TWO OUTPUT OPTION VOUT1 R14 R13 VOUT2 dc1661a F03 Figure 3. Using Demo Board Options dc1661af 3 DEMO MANUAL DC1661A PARTS LIST ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components For DC1424A-A 1 5 C1, C2, C5, C11, C15 CAP, X5R, 4.7µF, 16V, 20% 1206 AVX, 1206YD475MAT2A 2 4 C3, C4, C9, C10 CAP, X5R, 22µF, 25V, 10% 1210 AVX, 12103D226KAT2A 3 1 C6 CAP, NPO, 100pF, 25V, 10% 0402 AVX, 04023A101KAT2A 4 2 C7, C12 CAP, X5R, 0.1µF, 25V, 10% 0402 AVX, 04023D104KAT2A 5 1 C8 CAP, X7R, 4700pF, 25V, 10% 0402 AVX, 04023C472KAT2A 6 2 D1, D2 DIODE, SCHOTTKY, POWERMITE DIODES, MBRM560-13-F 7 2 L1, L2 INDUCTOR, 2.2µH 8A POWER VISHAY, IHLP2525CZER2R2M01 8 1 Q2, MOSFET, P-CH 20V 25A 1212-8 VISHAY, Si7141DP-T1-GE3 9 1 R1 RES, CHIP, 22.1k, 1%, 0805 VISHAY, CRCW080522K1FKEA 10 2 R3, R8 RES, CHIP, 100k, 1%, 0402 VISHAY, CRCW0402100KFKED 11 1 R4 RES, CHIP, 64.9k, 1%, 0805 VISHAY, CRCW080564K9FKEA 12 1 R5 RES, CHIP, 10k, 1%, 0402 VISHAY, CRCW040210K0FKED 13 1 R6 RES, CHIP, 10k, 1%, 0805 VISHAY, CRCW080510K0FKEA 14 2 R7, R9 RES, CHIP, 86.6k, 1%, 0402 VISHAY, CRCW040286K6FKED 15 1 R12 RES, CHIP, 6.34k, 1%, 0402 VISHAY, CRCW04026K34FKED 16 1 U1 IC, LT3579EFE-1, 20 pin TSSOP-4.4mm LINEAR TECHNOLOGY, LT3579EFE-1#PBF 17 1 U2 IC, LT3579EFE, 20 pin TSSOP-4.4mm LINEAR TECHNOLOGY, LT3579EFE#PBF 18 1 FAB, PRINTED CIRCUIT BOARD DEMO CIRCUIT 1661A Additional Demo Board Circuit Components 1 2 R13, R14 RES, CHIP, 0Ω, 0402 VISHAY, CRCW04020000Z0ED Hardware For Demo Board Only 1 4 E1 to E4 TESTPOINT, TURRET, 0.91” MILL-MAX, 2501-2-00-80-00-00-07-0 2 2 J1, J2 BANANA JACK KEYSTONE, 575-4 3 1 JP1 HEADER, 0.079 SINGLE ROW 3 PIN SAMTEC, TMM-103-02-L-S 4 1 XJP SHUNT, MTGS AT 4 SAMTEC, 2SN-BK-G 5 4 CORNERS STAND-OFF, NYLON 0.5” TALL KEYSTONE, 8833(SNAP ON) dc1661af 4 1 2 VIN OFF JP1 CLKOUT ON E4 J2 J1 3 2 R1 22.1K 0805 C1 4.7uF 16V 1206 R17 OPT 0805 VIN2 R6 10K 0805 R2 OPT 4 C11 4.7uF 16V 1206 C15 4.7uF 16V 1206 R3 100K GATE VIN 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. 2. INSTALL SHUNTS AS SHOWN. 1. ALL RESISTORS ARE IN 0402. ALL CAPACITORS ARE IN 0402. B 3 4 U1 C7 0.1uF R7 86.6K LT3579EFE-1 VC FB 2 1 R13 0 D2 MBRM560 2 CUSTOMER NOTICE R9 86.6K LT3579EFE U2 VC FB 1 D1 MBRM560 C8 4.7nF R5 10K THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. A.K. SCALE = NONE JESUS R. C10 22uF 25V 1210 C4 22uF 25V 1210 __ ECO DATE: N/A SIZE VIN D3 OPT GATE R12 6.34K 6.3K 1 2 3 5 6 7 8 E2 C5 4.7uF 16V 1206 E1 JESUS R. DATE VOUT 12-06-10 GND 12V, 3.5A APPROVED DEMO CIRCUIT 1661A LT3579EFE-1, LT3579EFE A Monday, December 06, 2010 IC NO. SHEET 1 3 REV. OF 1 TWO BOOST REGULATORS IN PARALLEL 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only Q2 Si7141DP PRODUCTION DESCRIPTION REVISION HISTORY TECHNOLOGY C9 22uF 25V 1210 3 REV 4 A TITLE: SCHEMATIC C13 OPT APPROVALS C14 OPT R16 10K OPT C6 100pF C3 22uF 25V 1210 R15 OPT R14 0 R4 64.9K 0805 LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO PCB DES. VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APP ENG. APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. C12 0.1uF CLKOUT SHDN GATE FAULT L2 VIN2 IHLP-2525CZER2R2M01 CLKOUT SHDN GATE FAULT C2 4.7uF 16V 1206 VIN L1 IHLP-2525CZER2R2M01 CLKOUT 16 17 FAULT R8 100K 16 17 3 4 FAULT CLKOUT VIN NOTE: UNLESS OTHERWISE SPECIFIED E3 OUTPUT 1 SYNC GND 5V-10V 5 6 7 8 5 VIN 5 20 1 2 3 SS 19 SS 19 VIN SYNC 10 9 8 7 6 SW1 SW1 SW1 SW1 SW1 RT 18 VIN 10 9 8 7 6 SW1 SW1 SW1 SW1 SW1 RT 18 VIN2 21 Q1 OPT 21 SYNC 20 11 12 13 14 15 SW2 SW2 SW2 SW2 SW2 GND 11 12 13 14 15 SW2 SW2 SW2 SW2 SW2 GND B 1 2 DEMO MANUAL DC1661A SCHEMATIC DIAGRAM dc1661af 5 DEMO MANUAL DC1661A 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 dc1661af 6 Linear Technology Corporation LT 0211 • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 2011