DEMO MANUAL DC1872A LTM4637 20A DC/DC Module Step-Down Regulator DESCRIPTION Demonstration circuit DC1872A features the LTM(R)4637EV, a high efficiency, high density switch mode step-down power Module(R) regulator. The input voltage range is from 4.5V to 20V. The output voltage is jumper programmable from 1.0V to 1.8V with a rated load current of 20A. Derating is necessary for certain VIN, VOUT, frequency and thermal conditions. The DC1872A offers the TRACK/SS pin, allowing the user to program output tracking or soft-start period. The DC1872A allows the user to choose pulse-skipping mode or Burst Mode(R) operation for higher efficiency at light load conditions. The LTM4637 data sheet must be read in conjunction with this demo manual prior to working on or modifying demo circuit DC1872A. Design files for this circuit board are available at http://www.linear.com/demo L, LT, LTC, LTM, Linear Technology, the Linear logo, Module and Burst Mode are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. PERFORMANCE SUMMARY PARAMETER CONDITIONS / NOTES Input Voltage Range VALUE 4.5V to 20V Output Voltage VOUT Jumper Selectable 1.0V, 1.2V, 1.5V, 1.8V 1.5% Maximum Continuous Output Current Derating Is Necessary for Certain Operating Conditions. See Data Sheet for Details 20ADC Operating Frequency RfSET =124k 520kHz Efficiency VIN = 12V, VOUT = 1.0V, IOUT = 20A 82.2% See Figure 2 Load Transient VIN = 12V, VOUT = 1.0V See Figure 3 BOARD PHOTO dc1872af 1 DEMO MANUAL DC1872A QUICK START PROCEDURE Demonstration circuit DC1872A is an easy way to evaluate the performance of the LTM4637EV. Please refer to Figure 1 for proper measurement equipment setup and follow the procedure below: 1. Place jumpers in the following positions for a typical 1.0VOUT application: RUN MODE TRACK/SS VOUT SELECT ON CCM SS 1.0V 2. With power off, connect the input power supply, load and meters as shown in Figure 1. Preset the load to 0A and VIN supply to be 0V. 3. Turn on the power at the input. Increase VIN to 12V (Do not apply more than the rated maximum voltage of 20V to the board or the part may be damaged). The output voltage should be regulated and deliver the selected output voltage 1.5%. 4. Vary the input voltage from 4.5V to 20V and adjust the load current from 0A to 20A. Observe the output voltage regulation, ripple voltage, efficiency, and other parameters. Output voltage ripple may be measured at J4 with a BNC cable and oscilloscope. The probe channel for VOUT should be set at 50 termination resistance to match the BNC cable. 5. (Optional) For optional load transient test, apply an adjustable pulse signal between IOSTEP_CLK and GND test points. The pulse amplitude sets the load step current amplitude. Keep the pulse width short (<1ms) and pulse duty cycle low (<5%) to limit the thermal stress on the load transient circuit. The load step current can be monitored with a BNC connected to J3 (15mV/A). - V + + V - - + + - + VIN + A LOAD - A - DC1872A F01 Figure 1. Proper Measurement Equipment Setup dc1872af 2 DEMO MANUAL DC1872A 100 100 90 90 80 80 70 70 EFFICIENCY (%) EFFICIENCY (%) QUICK START PROCEDURE 60 50 40 30 VIN = 5V VIN = 8V VIN = 12V VIN = 16V VIN = 20V 20 10 0 0 5 10 LOAD (A) 15 60 50 40 30 VIN = 5V VIN = 8V VIN = 12V VIN = 16V VIN = 20V 20 10 0 20 0 5 10 LOAD (A) DC1872A F02a DC1872A F02c (2c) VOUT = 1.5V 100 100 90 90 80 80 70 70 EFFICIENCY (%) EFFICIENCY (%) (2a) VOUT = 1.0V 60 50 40 30 VIN = 5V VIN = 8V VIN = 12V VIN = 16V VIN = 20V 20 10 0 0 5 10 LOAD (A) 15 20 15 60 50 40 30 VIN = 5V VIN = 8V VIN = 12V VIN = 16V VIN = 20V 20 10 0 20 0 5 10 LOAD (A) 20 15 DC1872A F02b DC1872A F02d (2b) VOUT = 1.2V (2d) VOUT = 1.8V Figure 2. Measured DC1872A Efficiency at Different VIN and VOUT Values (CCM Mode Enabled) VOUT 100mV/DIV IOUT_STEP 6.67A/DIV DC1872A F03 Figure 3. Measured Load Transient Response (VIN = 12V, VOUT = 1.0V, 0A to 10A Load Step) Figure 4. Thermal Image of LTM4637 (VIN = 12V, VOUT = 1.0V, ILOAD = 20A, Ambient Temperature = 21.6, No Forced Air Flow) dc1872af 3 DEMO MANUAL DC1872A PARTS LIST ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components 1 1 U1 IC, MICRO MODULE LINEAR TECH LTM4637EV 2 2 C5, C24 CAP, 1210 22F 10% 25V X5R MURATA GRM32ER61E226KE15L 3 1 C6 CAP, 150F 35V ELEC SUN ELEC 35CE150AX 4 1 C9 CAP, 0603 0.1F 10% 50V X7R TDK C1608X7R1H104K 5 1 C10 CAP, 0603 150pF 10% 25V NPO AVX 06033A151KAT2A 6 2 C11, C12 CAP, 1210 100F 20% 6.3V X5R TDK C3225X5R0J107M 7 1 C16 CAP, 7343 470F 20% 2.5V POSCAP SANYO 2R5TPE470M9 8 1 C18 CAP, 0603 1.5nF 5% 25V X7R AVX 06033C152JAT2A 9 1 C19 CAP, 0603 82pF 5% 25V NPO AVX 06033A820JAT2A 10 1 R9 RES, 0603 124k 1% 1/10W VISHAY CRCW0603124K0FKEA 11 1 R20 RES. 0603 100k 5% 1/10W VISHAY CRCW0603100KJNEA 12 1 R15 RES, 0603 30.1k 1% 1/10W VISHAY CRCW060330K1FKEA Additional Demo Board Components 1 1 Q1 XSTR, MOSFET, N-CHANNEL 30V VISHAY SUD50N03-09P-GE3 2 1 R1 RES, 0603 10k 5% 1/10W VISHAY CRCW060310K0JNEA 3 1 R2 RES, 2512 0.015 1% 1W VISHAY WSL2512R0150FEA 4 2 R3, R13 RES, 0603 60.4k 1% 1/10W VISHAY CRCW060360K4FKEA 5 2 R4, R12 RES, 0603 90.9k 1% 1/10W VISHAY CRCW060390K9FKEA 6 1 R7 RES, 0603 0 JUMPER VISHAY CRCW06030000Z0ED 7 1 R10 RES. 0603 20k 5% 1/10W VISHAY CRCW060320K0JNEA 8 1 R14 RES, 0603 40.2k 1% 1/10W VISHAY CRCW060340K2FKEA 9 2 R18, R19 RES, 0603 10 5% 1/10W VISHAY CRCW060310R0JNEA 10 3 C1, C2, C8 CAP, 0603 1F 20% 10V X5R TAIYO YUDEN LMK107BJ105MA-T 11 0 C3, C4, C13, C22, C23 CAP, 1210 OPTION OPTION 12 0 C7 CAP, 0805 OPTION OPTION 13 0 C14, C15, C17, C20, C21 CAP, 0603 OPTION OPTION 14 0 R5, R6, R8, R11, R16 RES, 0603 OPTION OPTION 1 11 E1-E11 TURRET MILL-MAX 2501-2-00-80-00-00-07-0 2 2 JP1, JP2 HEADER, 3-PIN, 2mm SAMTEC TMM-103-02-L-S 3 4 JP1, JP2, JP3, JP4 SHUNT SAMTEC 2SN-BK-G 4 2 JP3, JP4 HEADER, 4-PIN, DOUBLE ROW, 2mm SAMTEC TMM-104-02-L-D 5 4 J1, J2, J5, J6 JACK, BANANA KEYSTONE 575-4 6 2 J3, J4 CONN., VERT. PC-MNT, BNC 50 OHM CONNEX 112404 7 4 MH1, MH2, MH3, MH4 STANDOFF, SNAP ON KEYSTONE_8834 Hardware dc1872af 4 DEMO MANUAL DC1872A SCHEMATIC DIAGRAM dc1872af 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 DC1872A 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 (c) 2004, Linear Technology Corporation dc1872af 6 Linear Technology Corporation LT 1212 * PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 FAX: (408) 434-0507 www.linear.com LINEAR TECHNOLOGY CORPORATION 2012