DEMO MANUAL DC1722A LTC3864 55V Low IQ Step-Down DC/DC Converter with 100% Duty Cycle Capability DESCRIPTION Demonstration circuit 1722A is a high voltage, current mode DC/DC step-down converter featuring the LTC®3864. for larger MOSFET and diode packages on the back of the board for higher output current requirements. The board operates from an input range of 3.5V to 55V, and provides a 5V, 2A output when the input exceeds 5V. The PMOSFET architecture allows it to operate seamlessly up to 100% duty cycle, and function as a saturated switch below the regulation threshold, down to 3.5VIN. It operates at 350kHz and may be synchronized to an external clock. A soft-start feature controls output voltage slew rate at start-up, reducing current surge and voltage overshoot. Burst Mode® operation that improves efficiency at light loads can be enabled with a jumper. A power good output signal is provided. The demonstration board has options This board is suitable for a wide range of automotive, telecom, industrial, and other applications. The LTC3864 is available in small 12-pin thermally enhanced MSOP and DFN packages. For other output requirements, see the LTC3864 data sheet or contact the LTC factory. PERFORMANCE SUMMARY Design files for this circuit board are available at http://www.linear.com/demo/DC1722A L, LT, LTC, LTM, Linear Technology, Burst Mode 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 VIN Input Supply Range VOUT Output Voltage IOUT Output Current Range, Continuous fSW Switching (Clock) Frequency VOUT(P-P) Output Ripple VIN = 14V, IOUT = 2A (20MHz BW) VREG Output Regulation Line and Load (5.5VIN to 55VIN, 0AOUT to 2AOUT) POUT/PIN Efficiency (See Figure 3) VIN =14V, IOUT = 2A Approximate Size Component Area x Top Component Height MIN TYP 3.5 MAX 55 5.0 0 UNITS V V 2 A 350 kHz 15 mVP–P 0.23 84 0.6 × 0.6 × 0.14 % % Inches dc1722afa 1 DEMO MANUAL DC1722A QUICK START PROCEDURE Demonstration circuit 1722 is easy to set up to evaluate the performance of the LTC3864. Refer to Figure 1 for proper measurement equipment setup and follow the procedure below: NOTE: Make sure that the input voltage never exceeds 55V. NOTE: When measuring the output voltage ripple, care must be taken to avoid a long ground lead on the oscilloscope probe. Measure the output voltage ripple by touching the probe tip and ground ring directly across the last output capacitor as shown in Figure 1. 5.Once the proper output voltage is established, connect a variable load capable of sinking 2A at 5V to the output terminals VOUT and GND. Set the current for 0A. 1.Set an input power supply that is capable of 3.5V to 55V to 6V. Then turn off the supply. 2.With power off, connect the supply to the input terminals VIN and GND. a. Input voltages lower than 3.5V can keep the converter from turning on due to the undervoltage lockout feature of the LTC3864. b.If efficiency measurements are desired, an ammeter capable of measuring 2ADC or a resistor shunt can be put in series with the input supply in order to measure the DC1722A’s input current. c. A voltmeter with a capability of measuring at least 55V can be placed across the input terminals in order to get an accurate input voltage measurement. 2 3.Turn on the power at the input. 4.Check for the proper output voltage of 5V. Turn off the power at the input. a. If efficiency measurements are desired, an ammeter or a resistor shunt that is capable of handling 2ADC can be put in series with the output load in order to measure the DC1722A’s output current. b.A voltmeter with a capability of measuring at least 5V can be placed across the output terminals in order to get an accurate output voltage measurement. 6.Turn on the power at the input. NOTE: If there is no output, temporarily disconnect the load to make sure that the load is not set too high. 7.Once the proper output voltage is again established, adjust the load and/or input within the operating range and observe the output voltage regulation, ripple voltage, efficiency and other desired parameters. dc1722afa DEMO MANUAL DC1722A QUICK START PROCEDURE DC1722a F01 Figure 1. Proper Measurement Equipment Setup dc1722afa 3 DEMO MANUAL DC1722A QUICK START PROCEDURE 95 90 EFFICIENCY (%) 85 80 75 70 65 VIN = 6V VIN = 14V VIN = 28V VIN = 55V 60 55 0.01 0.1 1 IOUT (A) 10 DC1722a F02 Figure 2. Efficiency with Burst Mode Operation at Light Loads 10mV/DIV 2µs/DIV DC1722a F03 Figure 3. Output Ripple at 14VIN and 2AOUT (10mV, 2µs/DIV, 20MHz) 4 dc1722afa DEMO MANUAL DC1722A QUICK START PROCEDURE 1A/DIV 50mV/DIV 100µs/DIV DC1722a F04 Figure 4. Transient Response Waveform at 14VIN and 1A - 2A - 1AOUT (1A, 50mV,100µs/DIV) dc1722afa 5 DEMO MANUAL DC1722A PARTS LIST ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components 1 1 CIN1 CAP, 10μF 20% 63V ALUM SUN ELEC. 63HEH10M 2 1 CIN2 CAP, 1210 2.2μF 10% 100V X7R MURATA GRM32ER72A225KA35L 3 2 COUT1, COUT2 CAP, 1812 100μF 20% 6.3V X5R TDK C4532X5R0J107M 4 1 COUT3 CAP, 0603 1μF 10% 6.3V X5R TAIYO YUDEN JMK107BJ105KA-T 5 1 C1 CAP, 0402 100pF 5% 25V NPO AVX 04023A101JAT2A 6 1 C2 CAP, 0402 2200pF 10% 25V X7R AVX 04023C222KAT2A 7 1 C4 CAP, 0402 47pF 5% 25V NPO AVX 04023A470JAT2A 8 1 C5 CAP, 0603 0.47μF 20% 16V X7R AVX 0603YC474MAT2A 9 1 C6 CAP, 0402 0.1μF 20% 16V X5R AVX 0402YD104MAT2A 10 1 C7 CAP, 0805 0.1μF 20% 100V X5R TDK C2012X5R2A104M 11 1 C8 CAP, 0402 220pF 5% 25V NPO AVX 04023A221JAT2A 12 1 D1 DIODE, SUPER BARRIER RECTIFIER 100V DFN3030-8 DIODES INC./ZETEX SBR3U100LP-7 13 1 L1 IND, 10μH COILCRAFT XAL5050-103ME 14 1 Q1 XSTR, FET P-CHANNEL 60V FAIRCHILD SEMI FDMC5614P 15 5 R1, R4, R6, R8, R10 RES, 0402 0Ω JUMPER VISHAY CRCW04020000Z0ED 16 1 R2 RES, 0402 10k 1% 1/16W VISHAY CRCW040210K0FKED 17 1 R3 RES, 0402 80.6k 1% 1/16W VISHAY CRCW040280K6FKED 18 1 R5 RES, 0402 422k 1% 1/16W VISHAY CRW0402422KFKED 19 1 R7 RES, 2010 0.025Ω 1% 1/2W VISHAY WSL2010R0250FEA 20 1 R9 RES, 0402 100k 5% 1/16W VISHAY CRCW0402100KJNED 21 1 U1 IC, VOLTAGE REG. MSOP(12)-MSE LINEAR TECH. LTC3864EMSE Additional Demo Board Circuit Components 1 0 CIN3 CAP, 1210 2.2μF 10% 100V X7R OPTION MURATA GRM32ER72A225KA35L OPTION 2 0 C9 CAP, D CASE OPTION OPTION 3 0 D2 DIODE, SCHOTTKY, 5A POWERDi5 OPTION DIODES INC./ZETEXPDS5100-13 OPTION 4 0 L1 – ALTERNATE IND, 10μH TOKO B1134AS-100M 5 0 L1 – ALTERNATE IND, 10μH WURTH ELECTRONIK 744071100 6 0 Q2 XSTR, MOSFET P-CHANNEL 60V OPTION VISHAY SILICONIX Si7465DP OPTION 7 0 R11 RES, 0402 OPTION OPTION 1 4 E1, E2, E8, E9 TURRET MILL MAX 2501-2-00-80-00-00-07-0 2 5 E3, E4, E5, E6, E7 TURRET MILL MAX 2308-2-00-80-00-00-07-0 3 1 JP1 HEADER, 3-PIN SINGLE ROW 2mm SAMTEC TMM-103-02-L-S 4 1 JP2 HEADER, 3-PIN DOUBLE ROW 2mm SAMTEC TMM-103-02-L-D 5 4 MH1, MH2, MH3, MH4 STANDOFF, SNAP ON KEYSTONE_8831 6 2 XJP1, XJP2 SHUNT, 2mm SAMTEC 2SN-BK-G Hardware 6 dc1722afa 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 TRACK CLKIN GND VIN 5V - 55V (3.5V Min) E4 E3 E2 E1 5 5 R3 80.6K 1% C4 47pF 5% R4 0 Ohm JP2 5 6 SKIP 3 1 2 BURST CLKIN 4 MODE CIN1 + 10uF 63V R5 422K 1% C2 2200pF R2 10.0K 1% 0.1uF C6 0 Ohm R1 4 ITH VFB SS GND FREQ PLL/MODE C8 220pF 5% 6 5 4 3 2 1 13 GND LTC3864EMSE U1 4 R11 (OPT) R9 100k VOUT PGOOD RUN CAP SENSE VIN GATE CIN3 2.2uF 100V 1210 (OPT) VIN 3 2 JP1 SHDN 1 R10 0 Ohm 0.1uF 100V 0805 C7 OFF ON R6 3 THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. C:\DESIGN\17\1722A-3.3\1722A-3.3.DSN 2 RB/MI SCALE = NONE DAVID B. 2 DATE: N/A SIZE E5 E9 04/19/16 E8 GND VOUT 5V / 2A D. B. D. B. APPROVED IC NO. Tuesday, April 19, 2016 1 LTC3864EMSE DEMO CIRCUIT 1722A SHEET 1 OF 1 3.3 REV. LTC CONFIDENTIAL - FOR CUSTOMER USE ONLY 60V, LOW IQ , STEP-DOWN CONTROLLER TITLE: SCHEMATIC DATE 04/17/12 COUT3 1uF 6.3V 0603 E6 VOUT 1 1630 McCarthy Blvd. Milpitas, CA 95035 www.linear.com Phone: (408)432-1900 Fax: (408)434-0507 C9 (OPT) "D" Case + TECHNOLOGY COUT2 100uF 6.3V 1812 CHANGE 3.3 COUT1 100uF 6.3V 1812 PROD 3 REVISION HISTORY DESCRIPTION REV XAL5050-103ME COILCRAFT D1 SBR3U100LP-7 L1 10uH Q2 Si7465DP (OPT) ECO APPROVALS Q1 FDMC5614P D2 PDS5100-13 PowerDi5 (OPT) 0 Ohm CUSTOMER NOTICE E7 PGOOD 0.47uF 0603 C5 C1 100pF 5% 0 Ohm R8 R7 0.025 2010 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 APPLICATION. COMPONENT SUBSTITUTION AND PRINTED APP ENG. CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. 7 8 9 10 11 12 CIN2 2.2uF 100V 1210 VIN 3 A B C D DEMO MANUAL DC1722A SCHEMATIC DIAGRAM dc1722afa 7 DEMO MANUAL DC1722A 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 8 dc1722afa Linear Technology Corporation LT 0516 REV A • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 2013