DEMO MANUAL DC2057A LTC3638EMSE High Efficiency, High VIN, 250mA Step-Down Converter DESCRIPTION Demonstration circuit 2057A is a high input voltage, 250mA output DC/DC power supply featuring the LTC®3638. The IC operates with high efficiency Burst Mode® operation and includes an internal high side power MOSFET. The board will accept an input voltage between 4V and 140V, and provide jumper selected output voltages of 1.8V, 3.3V, 5V with an option for additional voltages. The IC includes internal soft-start and a provision for increasing soft-start time. Included on the board is an ON/OFF jumper that can also be configured as a precision undervoltage lockout. Additional PC pads are included for programming current limit to optimize efficiency and for reducing output voltage ripple and reducing component size. A terminal (FBO) is included to allow multiple boards to be paralleled for higher output current. PERFORMANCE SUMMARY PARAMETER Output voltages between 800mV and VIN can be programmed using optional resistors (higher voltage rating output capacitors may be required). The LTC3638 data sheet gives a complete description of the IC operation and application information. The data sheet must be read in conjunction with this quick start guide. Design files for this circuit board are available at http://www.linear.com/demo L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Specifications are at TA = 25°C CONDITION Input Voltage Range VALUE 4V to 140V 1.8V Output Voltage VIN = 12V, IOUT = 0A to 250mA 1.8V ±2% 3.3V Output Voltage VIN = 12V, IOUT = 0A to 250mA 3.3V ±2% 5V Output Voltage VIN = 12V, IOUT = 0A to 250mA 5V ±2% Maximum Output Current, IOUT VIN = 4V to 140V, VOUT = 1.8V, 3.3V or 5V 250mA Typical Efficiency VIN = 12V, VOUT = 5V, IOUT = 250mA 83.7% Typical Output Ripple VIN = 140V, VOUT = 5V, IOUT = 100mA (20MHz BW) 81mVP-P dc2057af 1 DEMO MANUAL DC2057A QUICK START PROCEDURE Demonstration circuit 2057A is easy to set up to evaluate the performance of the LTC3638. Refer to Figure 1 for the proper measurement equipment setup and follow the procedure below: 7.With power off, move jumpers JP1 and JP2 to the other fixed voltage settings (1.8V or 3.3V). Repeat steps 5 and 6. Check for the proper output voltage and other parameters. 1.With power off, connect the input power supply (set for 0V) to VIN and GND (input return). 3.Connect the 5V output load between VOUT and GND (Initial load: no load). Note: When measuring the output or input voltage ripple, do not use the long ground lead on the oscilloscope probe. See Figure 2 for the proper scope probe technique. Short, stiff leads need to be soldered to the (+) and (–) terminals of an output capacitor. The probe’s ground ring needs to touch the (–) lead and the probe tip needs to touch the (+) lead. 4.Connect the DVMs to the input and outputs. Additional Notes: 5.Turn on the input power supply and slowly increase to 12V. Check for the proper output voltages. (5V output should be within 5V ±2%.) 1. CAUTION: Be careful when testing with high voltage. High voltage can result in an electric shock if care is not taken. 6.Once the proper output voltages are established, adjust the loads within the operating range and observe the output voltage regulation, ripple voltage and other parameters. 2. For 5V output, VIN input voltage should be at least 5V or higher. 2.Select 5V output using jumper JP1 (B position) and JP2 (A position). Select ON position for JP3. dc2057af 2 DEMO MANUAL DC2057A QUICK START PROCEDURE Figure 1. Proper Measurement Equipment Setup + VOUT COUT – GND Figure 2. Measuring Output Voltage Ripple dc2057af 3 DEMO MANUAL DC2057A QUICK START PROCEDURE LTC3638 1.8VOUT Efficiency vs Load Current LTC3638 3.3VOUT Efficiency vs Load Current dc2057af 4 DEMO MANUAL DC2057A QUICK START PROCEDURE LTC3638 5VOUT Efficiency vs Load Current dc2057af 5 DEMO MANUAL DC2057A PARTS LIST ITEM QTY REFERENCE PART DESCRIPTION 1 2 MANUFACTURER/PART NUMBER 1 C1 CAP.SMD ALUM. ELECT., 22µF, 200V KE0-MVA NIPPON CHEMI-CON, EMVE201ARA220MKG5S 1 C2 CAP., X7R, 1µF, 200V, 10% 2220 KEMET, C2220X105K2RACTU 3 1 C4 CAP., X7R, 47nF, 25V, 10% 0603 AVX, 06033C473KAT2A 4 2 C6, C7 CAP., X7R, 100µF, 10V, 20% 1210 TAIYO YUDEN, LMK325ABJ107MMH-T 5 1 C9 CAP., X7R, 0.1µF, 25V, 10% 0603 AVX, 06033C104KAT2A 6 1 D1 DIODE, SBR1U200P1 DIODES, SBR1U200P1-7 7 1 L1 INDUCTOR, 150µH SUMIDA, CDRH105R-151 8 1 R1 RES., CHIP, 2M, 1/16W, 5% 0603 VISHAY, CRCW06032M00JNEA 9 1 U1 IC., LTC3638EMSE MSE16(12), 4X3MM LINEAR TECH., LTC3638EMSE Additional Demo Board Circuit Components 10 0 C3 (OPT) CAP., 0603 OPT 11 0 C8, C10 (OPT) CAP., 1210 OPT 12 0 R2, R4, R7, R8 (OPT) RES., 0603 OPT 13 2 R3, R6 RES., CHIP, 0Ω, 1/16W, 0603 VISHAY, CRCW06030000Z0EA 14 5 E1, E2, E3, E4, E5 TESTPOINT, TURRET 0.094" MILLMAX 2501-2-00-80-00-00-07-0 15 3 JP1, JP2, JP3 JMP, 0.079 SINGLE ROW HEADER, 3-PIN SULLINS, NRPN031PAEN-RC 16 3 XJP1, XJP2, XJP3 SHUNT, 0.079" CENTER SAMTEC, 2SN-BK-G 17 4 STAND-OFFS STAND-OFF, NYLON 0.5" KEYSTONE, 8833 (SNAP ON) Hardware dc2057af 6 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. A B C D + 5 3 4 3 TECHNOLOGY 2 1 1 2 4 5 A B C D DEMO MANUAL DC2057A SCHEMATIC DIAGRAM dc2057af 7 DEMO MANUAL DC2057A 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 dc2057af 8 Linear Technology Corporation LT 0114 • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 2014