DEMO MANUAL DC1734A LT8582 Dual 3A Boost/Inverting/SEPIC DC/DC Converter DESCRIPTION Demonstration circuit 1734A features the dual channel LT®8582 in boost and inverting regulator configurations. The circuit is designed to convert a 5V to 10V input source to 12V at 900mA and –12V at 590mA as shown in Table 1. Table 1. Maximum Guaranteed Output Currents VIN (V) MAX ILOAD1 (mA) MAX ILOAD2 (mA) 4.5 775 540 5.0 900 590 5.5 1000 625 To limit the temperature rise of the chip to 40°C, on the demo board with no air flow, the maximum combined output power is 15W. Additional input bulk capacitance may be needed, subject to source impedance. DC1734A is designed to survive output short circuit events. On the positive channel an external disconnect MOSFET protects the boost converter. The negative channel is based on dual inductor inverting topology and does not need the external MOSFET as it is inherently output short protected. The circuit board includes an option to install the external disconnect MOSFET at the input side of the positive channel. To use it, remove Q1 and R1 from the top of the circuit board and install them on the back, in the location of Q2 and R2. Then, place a jumper from Q1’s source to drain and cut the top copper as shown in Figure 6. PERFORMANCE SUMMARY SYMBOL PARAMETER VIN Input Supply Range VOUT1 VOUT2 fS To change the topology of channel 1 from boost to inverting: Replace D1 with a capacitor similar to C12, replace C2 with a diode similar to D3, placing the diode so that its cathode is connected to ground, and replace R16 with an inductor similar to L3. To change the topology of channel 2 from inverting to boost: Replace C12 with a diode similar to D1, placing the diode so that its anode is connected to L2, replace D3 with a capacitor similar to C2, and replace L3 with a jumper resistor similar to R16. However, this configuration will not be output short protected since it lacks the external disconnect MOSFET. Each channel of the LT8582 includes a 42V master and slave power switch combination with 3A total current and can easily be configured as a boost, SEPIC, inverting or flyback converter. The LT8582 has a 2.5V to 22V operating input range, UVLO, soft-start, programmable switching frequency and many other features. The LT8582 data sheet gives a complete description of the part, its operation and application information. The data sheet must be read in conjunction with this quick start guide for working on or modifying the demo circuit 1734A. 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. (TA = 25°C) CONDITIONS MIN TYP MAX Channel 1 Output Voltage Accuracy VIN = 5V to 10V, ILOAD = 900mA 11.6 10 V 12 12.4 V Channel 1 Output Voltage Ripple VIN = 5V, ILOAD = 900mA 60 Channel 1 Efficiency VIN = 5V, ILOAD = 900mA 86 % Channel 1 Efficiency VIN = 10V, ILOAD = 900mA 92 % Channel 2 Output Voltage Accuracy VIN = 5V to 10V, ILOAD = 590mA 5 –11.5 –12 UNITS mVPP –12.3 V Channel 2 Output Voltage Ripple VIN = 5V, ILOAD = 590mA 56 mVPP Channel 2 Efficiency VIN = 5V, ILOAD = 590mA 83 % Channel 2 Efficiency VIN = 10V, ILOAD = 590mA 85 % 1 MHz Switching Frequency dc1734af 1 DEMO MANUAL DC1734A QUICK START PROCEDURE Demonstration circuit DC1734A is easy to set up to evaluate the performance of the LT8582. Refer to Figure 1 for proper measurement equipment set-up and follow the procedure below. 1. Place the on board jumpers in the following positions: To measure voltage ripple, care must be taken to avoid a long ground lead on the oscilloscope probe. Remove the oscilloscope probe end cap and ground lead and set the bandwidth limit on the oscilloscope. Measure the input voltage ripple by touching the probe tip and ground directly across VIN and GND terminals. See Figure 2 for proper input voltage ripple measurement technique. Measure the positive output voltage ripple by touching the probe tip directly across output capacitor C16 terminals, connecting the probe ground terminal to the board’s GND plane. Measure the negative output voltage ripple by touching the probe tip directly across output capacitor C9, connecting the probe ground terminal to the board’s GND plane. See Figure 3 for proper output voltage ripple measurement technique. 2. With power off, connect the input power supply to VIN and GND. Apply 7.5V to the input (source must have greater than 10A capability). To activate boost converter: JP1 ON To activate inverting converter: JP2 ON 3. Check for the proper output voltages. NOTE. If there is no output, temporarily disconnect the load to make sure that the load is not set too high. 4. Once the proper output voltage is established, adjust the load and the input voltage within the operating range and observe the output voltage regulation, ripple voltage, efficiency and other parameters. The efficiency graphs of the two channels are provided in Figure 4 and Figure 5. Figure 1. Proper Measurement Equipment Setup dc1734af 2 DEMO MANUAL DC1734A QUICK START PROCEDURE OSCILLOSCOPE PROBE VIN GND Figure 2. Proper Input Voltage Ripple Measurement Technique OSCILLOSCOPE PROBE SOLDER A SMALL PIECE OF SOLID WIRE SOLDER OUTPUT CAP. BOARD GND PLANE Figure 3. Proper Output Voltage Ripple Measurement Technique dc1734af 3 DEMO MANUAL DC1734A QUICK START PROCEDURE 100 90 EFFICIENCY (%) 80 70 60 50 40 30 20 10 0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 LOAD CURRENT (A) dc1734a F04 Figure 4. Channel 1 Boost Regulator Efficiency at VIN = 5V 100 90 EFFICIENCY (%) 80 70 60 50 40 30 20 10 0 0 0.1 0.2 0.3 0.4 LOAD CURRENT (A) 0.5 0.6 dc1734a F05 Figure 5. Channel 2 Inverting Regulator Efficiency at VIN = 5V dc1734af 4 DEMO MANUAL DC1734A BOARD MODIFICATIONS SHORT Q1’s SOURCE AND DRAIN PADS HERE CUT COPPER HERE Figure 6. Using Channel 1 Input Disconnect Option (See Text) dc1734af 5 DEMO MANUAL DC1734A PARTS LIST ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components 1 3 C1, C2 CAP., X5R, 10μF, 16V, 20% 1206 AVX, 1206YD106MAT2A 2 1 C9, C16 CAP., X5R, 22μF, 16V, 20% 1206 TAIYO YUDEN, EMK316BJ226ML-T 3 2 C11, C17 CAP., X5R, 4.7μF, 16V, 20% 1206 TAIYO YUDEN, EMK316BJ475ML-T 4 2 C4, C8 CAP., X7R, 2.2nF, 50V, 10%, 0402 AVX, 04025C222KAT2A 5 2 C5, C10 CAP., NPO, 100pF, 16V, 10%, 0402 AVX, 0402YA101KAT2A 6 2 C6, C7 CAP., X7R, 0.1μF, 16V, 10% 0402 TDK, C1005X7R1C104K 7 1 C12 CAP., X7R, 2.2μF, 25V, 10%, 0805 MURATA, GRM21BR71E225KA73L 8 1 D1 RECTIFIER, DFLS220L, PowerDI-123 DIODES/ZETEX, DFLS220L-7 9 1 D3 RECTIFIER, DFLS130L, PowerDI-123 DIODES/ZETEX, DFLS130L-7 10 1 L1 INDUCTOR, 4.7μH VISHAY, IHLP2525CZER4R7M11 11 1 L2 INDUCTOR, 10μH VISHAY, IHLP2525CZER100M11 12 1 L3 INDUCTOR, 10μH VISHAY, IHLP2020BZER100M11 13 1 Q1 P-CH MOSFET, FDMC510P, POWER-33 FAIRCHILD, FDMC510P 14 1 R1 RES., CHIP, 6.04k, 1/16W, 1% 0402 VISHAY, CRCW04026K04FKED 15 1 R3 RES., CHIP,130k, 1/10W, 1%, 0603 NIC, NRC06F1303TRF 16 2 R4, R11 RES., CHIP, 232k, 1/8W, 1%, 0805 VISHAY, CRCW0805232KFKEA 17 1 R5 RES., CHIP, 8.06k, 1/16W, 1% 0402 VISHAY, CRCW04028K06FKED 18 2 R8, R10 RES., CHIP, 80.6k, 1/16W, 1% 0402 VISHAY, CRCW040280K6FKED 19 3 R6, R9, R13 RES., CHIP, 100k, 1/16W, 5% 0402 NIC, NRC04J104TRF 20 1 R12 RES., CHIP, 16.9k, 1/16W, 1% 0402 VISHAY, CRCW040216K9FKED 21 1 R15 RES., CHIP,143k, 1/10W, 1%, 0603 NIC, NRC06F1433TRF 22 1 R16 RES., CHIP, 0Ω, 1/4W, 1206 NIC, NRC12ZOTR 23 1 U1 IC., LT8582EDKD, DFN-24(7MMX4MM) LINEAR TECH., LT8582EDKD Additional Demo Board Circuit Components 1 0 C3, C14 CAP., 0603, OPTION 2 0 C13 CAP., 1206, OPTION 3 0 C15 CAP., SMD 8X10.5 & THRU HOLE 8X9.5, OPTION 4 0 D2 DIODE, SOD-323, OPTION 5 0 Q2 MOSFET, POWER-33, OPTION 6 0 R2 RES., CHIP, 0402, OPTION 7 0 R7, R14 RES., CHIP, 0805, OPTION Hardware for Demo Board Only 1 9 E1-E9 TESTPOINT, TURRET, .094" pbf MILL-MAX, 2501-2-00-80-00-00-07-0 2 2 JP1, JP2 3 PIN 0.079 SINGLE ROW HEADER SAMTEC, TMM103-02-L-S 3 2 XJP1, XJP2 SHUNT, .079" CENTER SAMTEC, 2SN-BK-G 4 4 (STAND-OFF) STAND-OFF, NYLON 0.25" KEYSTONE, 8831(SNAP ON) 5 1 FAB, PRINTED CIRCUIT BOARD DEMO CIRCUIT 1734A dc1734af 6 DEMO MANUAL DC1734A SCHEMATIC DIAGRAM dc1734af 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. 7 DEMO MANUAL DC1734A 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 dc1734af 8 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