DEMO MANUAL DC1636A LT3574 Isolated Monolithic Flyback Converter DESCRIPTION Demonstration circuit 1636A is an isolated flyback converter featuring the LT®3574. This demo circuit is designed for a 5.0V output from a 10V to 30V input. The maximum output current is 0.5A when the input voltage is higher than 20V. No third winding or opto-isolator is required for regulation. The part senses the isolated output voltage directly from the primary-side flyback waveform. The LT3574 operates with input supply voltages from 3V to 40V, and can deliver an output power up to 3W with no external power switch. The LT3574 utilizes boundary mode operation to provide a small magnetic solution PERFORMANCE SUMMARY PARAMETER with improved load regulation. The LT3574 can be used in industrial, automotive and medical applications where an isolated output is required. The LT3574 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 1636A. 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 CONDITION MIN Output Voltage VOUT VIN = 10V ~ 30V 4.75 Maximum Output Current IOUT VIN = 10V ~ 20V VIN = 20V ~ 30V 0.35 0.50 Switching Frequency VIN = 12V, IOUT = 0.35A VIN = 24V, IOUT = 0.5A 200 270 kHz kHz Voltage Ripple VOUT VIN = 24V, IOUT = 0.5A 50 mV Efficiency VIN = 24V, IOUT = 0.5A 84 % Input Voltage TYP MAX 30 V 5.0 5.25 V 10 UNITS A A dc1636af 1 DEMO MANUAL DC1636A QUICK START PROCEDURE Demo circuit 1636A is easy to set up to evaluate the performance of the LT3574. 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. See Figure 2 for proper scope probe technique. 1.With power off, connect the input power supply to VIN and GND. 2.Turn on the power at the input. Note: Make sure that the input voltage does not exceed 30V. 3.Check for the proper output voltages. Note: If there is no output, temporarily disconnect the load to make sure that the load current is not set too high. 4.Once the proper output voltage is established, adjust the load current within the operating range and observe the output voltage regulation, ripple voltage, efficiency and other parameters. dc1636af 2 DEMO MANUAL DC1636A QUICK START PROCEDURE Figure 1. Proper Measurement Equipment Setup VIN OR VOUT GND Figure 2. Measuring Input or Output Ripple dc1636af 3 DEMO MANUAL DC1636A PARTS LIST ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components 1 1 C2 CAP, 1210 4.7µF 10% 50V X7R AVX 12105C475KAT2A 2 1 C4 CAP, 1210 47µF 10% 10V X7R MURATA GRM32ER71A476K 3 1 C7 CAP, 0402 0.1µF 10% 25V X5R TDK C1005X5R1E104K 4 1 C8 CAP, 0402 100pF 5% 50V NPO AVX 04025A101JAT2A 5 2 C12, C9 CAP, 0805 1µF 10% 50V X7R MURATA GRM21BR71H105K 6 1 C10 CAP, 0805 0.22µF 10% 50V X7R TAIYO YUDEN UMK212BJ224KG-T 7 1 C11 CAP, 0402 4700pF 10% 50V X7R TDK C1005X7R1H472K 8 1 C13 CAP, 0402 10pF 5% 50V NPO MURATA1555C1H100JZ01D 9 1 D1 DIODE, SCHOTTKY, BARRIER RECTIFIER 2A DIODES INC B240A-13-F 10 1 D2 DIODE, RECTIFIER, BARRIER, SCHOTTKY 1.0A DIODES INC. DFLS1100 11 1 D3 DIODE, SCHOTTKY SOD323 CENTRAL SEMI CMDSH-3 12 1 R3 RES, 0402 357K OHMS 1% 1/16W VISHAY CRCW0402357KFKED 13 1 R6 RES, 0402 93.1k 1% 1/16W VISHAY CRCW040293K1FKED 14 1 R7 RES, 0402 84.5k 1% 1/16W VISHAY CRCW040284K5FKED 15 1 R8 RES, 0805 4.02k 1% 1/8W VISHAY CRCW08054K02FKEA 16 1 R9 RES, 0402 20k 1% 1/16W VISHAY CRCW040220K0FKED 17 1 R10 RES, 0402 10k 1% 1/16W VISHAY CRCW040210K0FKED 18 1 R11 RES, 0402 6.04k 1% 1/16W NIC NRC04F6041TRF 19 1 R15 RES, 0402 12.4k 1% 1/16W VISHAY CRCW040212K4FKED 20 1 T1 TRANSFORMER WURTH 750370041 21 1 U1 IC, MONOLITHIC FLYBACK CONVERTER LINEAR TECH LT3574EMS Additional Demo Board Circuit Components 1 1 C1 CAP, 22µF 20% 50V ELECT. SANYO 50CE22BS 2 0 C5 CAP, 22µF 20% 50V ELECT. OPTION SANYO 50CE22BS OPTION 3 0 C14 CAP, 1206 0.033µF 10% 50V X7R OPTION AVX 12065C333KAT2A OPTION 4 0 C19 CAP, 1210 4.7µF 10% 50V X7R OPTION MURATA GRM32ER71H475K OPTION 5 0 C20 CAP, 0603 0.01µF 10% 50V X7R OPTION NIC NMC0603X7R104K50TRPF OPTION 6 0 FB1 FERRITE BEAD OPTION TAIYO YUDEN FB MJ3216HS800 OPTION 7 0 L1 IND, 10uH OPTION SUMIDA CDRH4D22/HP OPTION 8 0 R2 RES, 0603 OPTION OPTION 9 1 R4 RES, 0805 1.4k 1% 1/8W VISHAY CRCW08051K40FKEA TURRET MILL-MAX 2501-2-00-80-00-00-07-0 Hardware-For Demo Board Only 1 5 E1, E2, E3, E5, E6 dc1636af 4 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. E1 E3 22 50V +C1 R10 10K 1% C7 0.1 SANYO 50CE22BS VIN C8 100pF C2 4.7 50V 1210 C12 1 50V 0805 12 10 11 C11 4700pF VC SS RILIM TC RREF RFB SW R11 6.04K 1% R7 84.5K 1% C9 1 50V 0805 C13 10pF D2 DFLS1100 C10 0.22 50V 0805 2 R8 4.02K 1% 0805 T1 CONTRACT NO. 4 3 THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. C20 0.01 0603 50V DATE: A SIZE BEAD C4 47 1210 10V 0.033uF C19 4.7 50V 1210 1206 10uH E5 APPROVED Zhongming Y. VOUT- 22 50V SANYO 50CE22BS E6 +C5 VIN VOUT- [email protected], VIN > 20V VOUT+ [email protected], VIN < 20V VOUT+ 06-05-13 DATE 1 IC NO. LT3574EMS 2 1 SHEET DEMO CIRCUIT 1636A ISOLATED MONOLITHIC FLYBACK CONVERTER OF 1-1 REV 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 Fax: (408)434-0507 LTC Confidential-For Customer Use Only SUMIDA CDRH4D22/HP L1 TECHNOLOGY C14 TAIYO YUDEN FB MJ3216HS800 FB1 R4 1.4K 1% 0805 CHANGED: C11,R15,R4 DESCRIPTION REVISION HISTORY OPTIONAL CIRCUIT 1 D1 B240A 2 VIN 1-1 REV 2 TITLE: SCHEMATIC 8 7 5 6 ECO 750370041 3 4 2 1 LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A APPROVALS CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO PCB DES. VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL ENG. APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. CUSTOMER NOTICE 14 13 4 R2 0603 OPT 1 D3 CMDSH-3 3 3 1 0 2 , 5 0 e n u J , y a d s e n d e W 5 U1 LT3574EMS SHDN/UVLO 2. ALL CAPACITOR VALUES ARE IN MICROFARADS, AND CASE SIZES ARE 0402. 1. ALL RESISTOR CASE SIZES ARE 0402. 7 15 R15 12.4K 1% R3 357K 1% R6 93.1K 1% NOTES: UNLESS OTHERWISE SPECIFIED, R9 20K 1% SHDN GND E2 VIN 10V - 30V 4 I M A B C D 5 VIN 6 BIAS TEST GND GND GND GND GND 2 1 3 8 9 16 1 2 5 A B C D DEMO MANUAL DC1636A SCHEMATIC DIAGRAM 1 1 . Z R E G I T dc1636af 5 DEMO MANUAL DC1636A 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 dc1636af 6 Linear Technology Corporation LT 0913 • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 2013