DEMO MANUAL DC1207A LT3504 Quad 40V/1A Step-Down Switching Regulator with 100% Duty Cycle Operation DESCRIPTION The demo circuit 1207A is a quad current mode PWM stepdown DC/DC converter featuring the LT®3504. The demo circuit is designed for 5V, 3.3V, 2.5V and 1.8V outputs from a 5.4V to 40V input. The current capability of each channel is up to 1A. Individual soft-start and current limit for each output as well as synchronous function simplify the complex design of quad-output power converters. Each converter is synchronized to either a common external clock input or a resistor programmable 250kHz to 2.2MHz internal oscillator. Programmable frequency allows optimization between efficiency and external component PERFORMANCE SUMMARY size. Each output can be independently disabled using its own RUN/SS pin. The LT3504 data sheet gives a complete description of the device, operation and application information. The data sheet must be read in conjunction with this quick start guide for the demo circuit 1207A. 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. Specifications are at TA = 25°C SYMBOL PARAMETER CONDITIONS MIN TYP MAX VIN Input Supply Range 5.4 VOUT1 Output Voltage 1 VOUT2 UNITS 40 V 4.75 5 5.15 V Output Voltage 2 3.135 3.3 3.40 V VOUT3 Output Voltage 3 2.375 2.5 2.575 V VOUT4 Output Voltage 4 1.71 1.8 1.854 V Frequency Switching Frequency 0.9 1 1.1 IOUT1 VOUT1 Maximum Output Current VIN = 5.4 ~ 40V 1 A IOUT2 VOUT2 Maximum Output Current VIN = 5.4 ~ 40V 1 A IOUT3 VOUT3 Maximum Output Current VIN = 5.4 ~ 40V 1 A IOUT4 VOUT4 Maximum Output Current VIN = 5.4 ~ 40V 1 A VOUT1(AC) VOUT1 Output Ripple VIN = 5.4 ~ 40V, IOUT1 = 1A, BW = 20MHz 20 mV VOUT2(AC) VOUT2 Output Ripple VIN = 5.4 ~ 40V, IOUT2 = 1A, BW = 20MHz 20 mV VOUT3(AC) VOUT3 Output Ripple VIN = 5.4 ~ 40V, IOUT3 = 1A, BW = 20MHz 20 mV VOUT4(AC) VOUT4 Output Ripple VIN = 5.4 ~ 40V, IOUT4 = 1A, BW = 20MHz 20 mV MHz dc1207af 1 DEMO MANUAL DC1207A DESCRIPTION 100 95 EFFICIENCY (%) 90 85 80 75 70 65 60 5 10 15 25 20 VIN (V) 30 35 40 Figure 1. System Efficiency at f = 1MHz with All Channels Sourcing 1A Current Figure 2. Thermal Image at VIN = 12V, f = 1MHz with All Channels Sourcing 1A Current QUICK START PROCEDURE The demo circuit 1207A is easy to set up to evaluate the performance of the LT3504. Refer to Figure 3 for proper measurement equipment setup and follow the procedure below: 3. Turn on the power at the input. 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 4 for proper scope probe technique. NOTE. If there is no output, temporarily disconnect the load to make sure that the load is not set too high. NOTE: Make sure that the input voltage does not exceed 40V. 4. Check for the proper output voltages. 5. Once the proper output voltages are established, adjust the load within the operating range and observe the output voltage regulation, ripple voltage, efficiency and other parameters 1. Place JP1-JP5 on ON position. 2. With power off, connect the input power supply to VIN and GND. dc1207af 2 DEMO MANUAL DC1207A QUICK START PROCEDURE Figure 3. DC1207A Proper Equipment Setup VIN GND Figure 4. Measuring Input or Output Ripple dc1207af 3 DEMO MANUAL DC1207A PARTS LIST ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components 1 2 C1, C2 CAP, 0805 10μF 10% 6.3V X5R AVX 08056D106KAT2A 2 2 C3, C4 CAP, 1206 22μF 10% 6.3V X5R AVX 12066D226KAT2A 3 1 C5 CAP, 0603 2.2μF 10% 6.3V X5R TAIYO YUDEN JMK107BJ225KAT 4 4 C6, C19, C26, C27 CAP, 0603 1μF 10% 50V X5R TDK C1608X5R1H105K 5 4 C7, C16, C17, C18 CAP, 0603 47nF 10% 10V X7R AVX 0603ZC473KAT2A 6 1 C21 CAP, 0402 22pF 5% 16V NPO AVX 0402YA220JAT2A 7 1 C22 CAP, 0402 43pF 5% 25V NPO AVX 04023A430JAT 8 1 C23 CAP, 0402 82pF 5% 50V NPO AVX 04025A820JAT 9 1 C24 CAP, 0402 100pF 10% 16V X7R AVX 0402YC101KAT 10 4 D1-D4 DIODE, SCHOTTKY BARRIER RECTIFIER ON SEMI MBRM140T3G 11 2 L1, L2 IND, 8.2μH SUMIDA CDRH5D28-8R2 12 2 L3, L4 IND, 4.2μH SUMIDA CDRH5D28-4R2 13 1 L5 IND, 10μH TAIYO YUDEN CBC2016100M 14 1 R1 RES, 0402 53.6k 1% 1/16W VISHAY CRCW040253K6FKED 15 1 R2 RES, 0402 31.6k 1% 1/16W VISHAY CRCW040231K6FKED 16 1 R3 RES, 0402 21.5k 1% 1/16W VISHAY CRCW040221K5FKEA 17 1 R4 RES, 0402 12.7k 1% 1/16W VISHAY CRCW040212K7FKED 18 1 R5 RES, 0402 18.2k 1% 1/16W VISHAY CRCW040218K2FKED 19 1 R6 RES, 0402 200k 5% 1/16W VISHAY CRCW0402200KJNED 20 1 R7 RES, 0402 475k 1% 1/16W VISHAY CRCW0402475KFKED 21 1 R8 RES, 0402 100k 1% 1/16W NIC NRC06F1003TRF 22 4 R9-R12 RES, 0402 10.2k 1% 1/16W VISHAY CRCW040210K2FKED 23 1 U1 IC, 40V QUAD BUCK REGULATOR LINEAR TECH. LT3504EUFD Additional Demo Board Circuit Components 1 1 C8 CAP, 22μF 20% 50V ALUM SANYO 50CE22BS 2 0 C9 CAP, OPTION OPTION 3 0 C10 CAP, 0603 OPTION OPTION 4 0 C11 CAP, 1206 OPTION OPTION 5 4 C12-C15 CAP, 0603 0.1μF 10% 50V X7R MURATA GRM188R71H104KA93D 6 0 FB1 FERRITE BEAD OPTION OPTION 7 0 L6 IND, OPTION OPTION Hardware—For Demo Board Only 1 16 E1-E16 TURRET MILL MAX 2501-2-00-80-00-00-07-0 2 5 JP1-JP5 HEADER, 3-PIN, 2mm SAMTEC TMM-103-02-L-S 3 5 JP1-JP5 SHUNT, 2mm SAMTEC 2SN-BK-G dc1207af 4 DEMO MANUAL DC1207A SCHEMATIC DIAGRAM dc1207af 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. 5 DEMO MANUAL DC1207A 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 dc1207af 6 Linear Technology Corporation LT 0712 • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com © LINEAR TECHNOLOGY CORPORATION 2012