DEMO MANUAL DC1757A LTC3789EGN High Efficiency 12V/12A Buck-Boost Converter DESCRIPTION Demonstration circuit 1757A is a high efficiency synchronous buck-boost DC/DC converter with a 6V to 36V input voltage range. It can supply a 12A maximum load current with a 12V output. The demo board features the LTC®3789EGN controller. The constant frequency current mode architecture allows a phase-lockable frequency of up to 600kHz, while an optional output current feedback loop provides support for applications such as battery charging. With a wide input range, wide output range and seamless transfers between operation modes, the LTC3789 is ideal for automotive, telecom, distributed DC power systems and battery-powered applications. The light load operation mode of the converter is determined with the MODE/PLLIN pin. Use JP2 jumper to select pulse-skipping mode or forced continuous mode (CCM) operation. The switching frequency is pre-set at about 200kHz. The converter can also be externally synchronized to an external clock through the MODE/ PLLIN pin (PLLIN terminal on the board). To shut down the converter, force the RUN pin below 1.2V (JP1: OFF). The power good output (PGOOD terminal) is low when the output voltage is outside of the ±10% regulation window. 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. PERFORMANCE SUMMARY PARAMETER (TA = 25°C) CONDITIONS VALUE Input Voltage Range 6V to 36V Output Voltage, VOUT VIN = 6V to 36V, IOUT = 0A to 12A 12V ±2% Maximum Output Current, IOUT VIN = 6V to 36V, VOUT = 12V 12A Typical Output Ripple VIN = 36V, IOUT = 12A (20MHz BW) 109mVP–P Typical Efficiency VIN = 12V, VOUT = 12V, IOUT = 12A 97.9% Typical Switching Frequency 200kHz QUICK START PROCEDURE Demonstration circuit 1757A is easy to set up to evaluate the performance of the LTC3789. Refer to Figure 1 for the proper measurement equipment setup and follow the procedure below: 1. With power off, connect the input power supply to VIN (6V to 36V) and GND (input return). 2. Connect the 12V output load between VOUT and GND (Initial load: no load). 3. Connect the DVMs to the input and outputs. 4. Turn on the input power supply and check for the proper output voltages. VOUT should be 12V ±2%. 5. 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. dc1757af 1 DEMO MANUAL DC1757A QUICK START PROCEDURE 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. Additional Notes: 1. On DC1757 board, two Coilcraft XAL1010 inductors are used in series instead of one larger inductor, for optimal size and performance. You may use a single inductor, such as Coilcraft SER2915L-332KL, if that is preferred. 2. Usually, the worst case efficiency at full load is at 6VIN. The board can deliver more output power at higher VIN. 3. R2 is needed for additional/constant output current limit only. Figure 1. Proper Measurement Equipment Setup + VOUT – COUT GND Figure 2. Measuring Output Voltage Ripple dc1757af 2 DEMO MANUAL DC1757A QUICK START PROCEDURE 100 98 EFFICIENCY (%) 96 94 92 90 88 86 VIN = 6V VIN = 12V VIN = 24V VIN = 36V 84 82 80 0 1 2 3 4 5 6 7 8 LOAD CURRENT (A) 9 10 11 12 Figure 3. Efficiency vs load current (VO = 12V, CCM) PARTS LIST ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER CAP., C0G, 100pF, 50V, 10% 0603 AVX, 06035A101KAT2A Required Circuit Components 1 1 CC1 2 1 CC2 CAP., X7R, 0.01μF, 50V, 10% 0603 AVX, 06035C103KAT2A 3 2 CSS, C15 CAP., X7R, 0.1μF, 50V, 10% 0603 AVX, 06035C104KAT2A 4 1 C11 CAP., NPO, 68pF, 50V, 10% 0603 AVX, 06035A680KAT2A 5 1 C10 CAP., X5R, 2.2μF, 10V, 10% 0603 AVX, 0603ZD225KAT2A 6 1 C24 CAP., X7R, 1μF, 16V, 20% 0603 AVX, 0603YC105MAT2A 7 2 CIN1, CIN2 CAP., Alum, 270μF, 50V, 20% SUN Electronics, 50ME270WX+T 8 2 COUT1, COUT2 CAP., OS-CON, 330μF, 16V, 20% SANYO, 16SEP330M+T 9 6 C16, C17, C19-C21, C28 CAP., X7R, 22μF, 16V, 20% 1210 AVX, 1210YC226MAT2A 10 2 C4, C22 CAP., X7R, 0.22μF, 16V, 20% 0603 AVX, 0603YC224MAT2A 11 5 C9, C14, C25-C27 CAP., X7R, 3.3μF, 50V, 20% 1210 AVX, 12105C335MAT2A 12 1 C18 CAP., X5R, 10μF, 6.3V, 20% 1206 AVX, 12066D106MAT2A 13 2 D4, D7 DIODE, SCHOTTKY 1A, 60V POWERDI123 DIODE INC., DFLS160-7 14 2 D5, D6 DIODE, SCHOTTKY 3A, 40V SMA DIODE INC., B340A-13-F 15 1 D8 DIODE, ZENER 5.1V 350MW SOT23-3 DIODE INC., BZX84C5V1-7-F dc1757af 3 DEMO MANUAL DC1757A PARTS LIST 16 2 L1, L2 Inductor, 1.5μH COILCRAFT, XAL1010-152ME 17 3 Q2, Q4, Q6 Mosfet N-channel INFINEON, BSC027N04LS G 18 3 Q3, Q5, Q9 Mosfet N-channel INFINEON, BSC010NE2LS 19 1 RFB1 RES., CHIP., 113k, 0.1W, 1% 0603 YAGEO, RC0603FR-07113KL 20 1 RFB2 RES., CHIP., 8.06k, 0.1W, 1% 0603 YAGEO, RC0603FR-078K06L 21 3 R18, R19, R32 Sensor Res., 0.01, 1W, 1% 2512 VISHAY, WSL2512R0100FEA 22 1 R2 Sense RES 0.003Ω, 1W, 1% 2512 SMD YAGEO, PR2512FKF070R003L 23 6 R3, R4, R9, R10, R13, R14 RES., CHIP., 100, 0.1W, 1% 0603 YAGEO, RC0603FR-07100RL 24 1 R5 RES., CHIP, 5.1, 0.1W, 5% 0805 YAGEO, RC0805JR-075R1L 25 1 R7 RES., CHIP., 100k, 0.1W, 1% 0603 YAGEO, RC0603FR-07100KL 26 1 R8 RES., CHIP., 10, 0.1W, 5% 0603 YAGEO, RC0603JR-0710RL 27 1 R26 RES., CHIP., 10, 0.1W, 5% 0805 YAGEO, RC0805JR-0710RL 28 6 R1, R11, R17, R23, R25, R27 RES., CHIP., 0 1% 0603 YAGEO, RC0603FR-070RL 29 1 R20 RES., CHIP., 0 2512 TEPRO, RN5326 30 1 R16 RES., CHIP., 1k, 0.1W, 1% 0603 YAGEO, RC0603FR-071KL 31 3 RC, R21, R24 RES., CHIP., 10k, 0.1W, 1% 0603 YAGEO, RC0603FR-0710KL 32 1 R30 RES., CHIP., 33.2k, 0.1W, 1% 0603 YAGEO, RC0603FR-0733K2L 33 1 R31 RES., CHIP., 12.1k, 0.1W, 1% 0603 YAGEO, RC0603FR-0712K1L 34 1 U1 I.C.,Volt. Reg. Linear Tech., LTC3789EGN#PBF Additional Demo Board Circuit Components: 1 0 CF1, CF, C7, C8 (OPT) CAP., 0603 2 0 C23, C29-C32, C35 (OPT) CAP., 1210 3 0 C12, C13 (OPT) CAP., 1206 4 0 Q7, Q8 (OPT) Mosfet 5 0 R6, R12, R15, R22 (OPT) RES., 0603 6 0 R28, R29 (OPT) RES., CHIP., 1206 Hardware-For Demo Board Only 1 2 JP1, JP2 HEADER, 3 PIN, 0.079 SINGLE ROW SAMTEC, TMM-103-02-L-S 2 2 3 4 XJP1, XJP2B SHUNT, .079" CENTER SAMTEC, 2SN-BK-G J1, J2, J3, J4 Connector, Banana Jack Keystone, 575-4 4 5 4 TP1, TP2, TP3, TP7 TESTPOINT, TURRET, .061" pbf MILL-MAX, 2308-2-00-80-00-00-07-0 6 TP4, TP5, TP6, TP10-TP12 TESTPOINT, TURRET, .094" pbf MILL-MAX, 2501-2-00-80-00-00-07-0 6 4 MTGS AT 4 CORNERS STAND-OFF, NYLON 0.5" KEYSTONE, 8833(SNAP ON) dc1757af 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. A B C D TP6 TP5 TP11 TP4 CSS 0.1uF EXTVCC PLLIN 3 JP2 MODE R31 12.1K 41.2K TP10 5 R16 1K CCM PULSE SKIP TP12 OFF OPT RFB1 113K 3 2 1 R25 0 R22 OPT INTVCC CF OPT VOS+ CC2 OPT C8 R14 100 OPT VIN+ VOUT 100 100 0.01uF C7 R10 R9 R13 100 10K R21 10K RC CC1 C10 2.2uF 2. INSTALL SHUNTS AS SHOWN. 1. ALL RESISTORS ARE IN OHMS, 0603. ALL CAPACITORS ARE IN MICROFARADS, 0603. 4 3 2 1 14 13 12 11 10 9 8 7 6 5 C11 68pF 4 100pF NOTE: UNLESS OTHERWISE SPECIFIED R24 10K INTVCC D8 BZX84C5V1 R15 CF1 OPT RFB2 8.06K JP1 VIN+ RUN 1 R30 ON 2 ITH SS SGND PGOOD R7 100K INTVCC 4 IOSENSE- IOSENSE+ ILIM VOUTSNS VINSNS RUN FREQ MODE/PLLIN SGND ITH SENSE1- SENSE1+ SS VFB TRIM SW2 TG2 BOOST2 BG2 EXTVCC INTVCC VIN BG1 PGND BOOST1 TG1 SW1 PGOOD LTC3789EGN U1 R3 100 15 16 17 18 19 20 21 22 23 24 25 26 27 28 0 R4 1uF 100 0805 R26 10 16V C24 INTVCC G 3 L1 1.5uH C12 (OPT) 1206 R28 (OPT) 1206 R18 0.01 1W R19 0.01 1W D5 B340A XAL1010-152ME VIN+ R1 0 R6 OPT VOUT C22 0.22uF 16V 6.3V D7 DFLS160 C18 10uF G Q4 BSC027N04LS Q7 (OPT) C4 0.22uF 16V R12 OPT D4 DFLS160 R27 0 R11 R23 0 R17 0 5.1 R5 Q2 Q6 BSC027N04LS C15 0.1uF 50V 3 D S D S 1.5uH CUSTOMER NOTICE R29 (OPT) C13 (OPT) D6 B340A C28 C21 C20 C19 C17 C16 22uF 16V 1210 C14 3.3uF 50V (OPT) 1210 2 2 THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AN D SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. CHARLIE Z. APP ENG. SCALE = NONE HZ PCB DES. __ ECO CIN1 270uF 50V + 1 330uF 16V + COUT2 VOUT CIN2 270uF 50V + J4 TP1 TP2 VOS+ R8 10 J3 J2 TP7 J1 TP3 DATE GND VOS- VOS+ 12V @ 12A MAX VOUT GND GND 6V - 36V VIN VIN+ CHARLIE Z. 6-9-11 APPROVED DATE: 1 SHEET LTC3789EGN DEMO CIRCUIT 1757A Friday, July 08, 2011 IC NO. 1 OF 1 2 REV. HIGH EFFICIENCY 12V / 12A BUCK-BOOST CONVERTER N/A SIZE B C D 1630 McCarthy Blvd. A Milpitas, CA 95035 Phone: (408)432-1900www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only PRODUCTION DESCRIPTION REVISION HISTORY TECHNOLOGY 330uF 16V + COUT1 2 REV TITLE: SCHEMATIC 1W 2512 R2 0.003 R20 0 APPROVALS C31 C30 C29 C23 (OPT) 1210 C32 LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS ; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY T O VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. R32 0.01 1W G Q9 Q5 BSC010NE2LS C35 3.3uF 50V (OPT) 1210 VOUT1 XAL1010-152ME L2 Q3 BSC010NE2LS Q8 (OPT) G C9 C25 C26 C27 3.3uF 50V 1210 D S D S 5 DEMO MANUAL DC1757A SCHEMATIC DIAGRAM dc1757af 5 DEMO MANUAL DC1757A 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 dc1757af 6 Linear Technology Corporation LT 1111 • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com © LINEAR TECHNOLOGY CORPORATION 2011