DEMO MANUAL DC2010A LT8612 42V, 6A Micropower Synchronous Step-Down Regulator Description Demonstration circuit 2010A is a 42V, 6A micropower synchronous step-down regulator featuring the LT®8612. The demo board is designed for 5V output from a 5.8V to 42V input. The wide input range allows a variety of input sources, such as automotive batteries and industrial supplies. The LT8612 is a compact, high efficiency, and high speed synchronous monolithic step-down switching regulator. The integrated power switches and inclusion of all necessary circuitry reduce the components count and solution size. Ultralow 3μA quiescent current in Burst Mode® operation achieves high efficiency at very light loads. Fast minimum on-time of 40ns enables high VIN to low VOUT conversion at high frequency. The LT8612 switching frequency can be programmed either via oscillator resistor or external clock over a 200kHz to 2.2MHz range. The SYNC pin on the demo board is grounded by default for low ripple burst mode operation. To synchronize to an external clock, move JP1 to SYNC and apply the external clock to the SYNC turret. Once JP1 is on SYNC position, a DC voltage of 3V or higher can be applied to the SYNC turret for pulse-skipping operation. Performance Summary SYMBOL PARAMETER VIN Input Supply Range VOUT Output Voltage IOUT Maximum Output Current fSW Switching Frequency EFE Efficiency at DC Figure 1 shows the efficiency of DC2010A circuit at 12V input. Figure 2 shows the LT8612 temperature rising on DC2010A demo board under different load conditions. The rated maximum load current is 6A, while derating is necessary for certain VIN and thermal conditions. The demo board has an EMI filter installed. To use the EMI filter, the input should be tied to VEMI terminal, not VIN terminal. The LT8612 data sheet gives a complete description of the part, operation and application information. The data sheet must be read in conjunction with this demo manual for demo circuit 2010A. The LT8612 is assembled in a 3mm × 6mm plastic QFN package with exposed pads for low thermal resistance. Proper board layout is essential for minimum EMI and maximum thermal performance. See the data sheet section PCB Layout and High Temperature Considerations. Design files for this circuit board are available at http://www.linear.com/demo/DC2010A 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 CONDITIONS MIN TYP 5.8 4.875 Derating Is Necessary for Certain VIN and Thermal Conditions 42 5 5.125 6 665 VIN = 12V , IOUT = 3A MAX UNITS V V A 700 94.3 735 kHz % dc2010afa 1 DEMO MANUAL DC2010A Description 80 95 70 TEMPERATURE RISING (°C) 100 EFFICIENCY (°C) 90 85 80 75 70 VIN = 12V VOUT = 5V fSW = 700kHz SYNC = GND 65 60 0 1 2 4 3 LOAD CURRENT (A) 5 VOUT = 5V fSW = 700kHz 60 IOUT = 6A 50 IOUT = 5.5A 40 IOUT = 5A IOUT = 4.5A 30 20 IOUT = 4A 10 6 dc2010a F01 Figure 1. Efficiency vs Load Current (Using VIN Terminal) 0 6 12 18 30 24 INPUT VOLTAGE (V) 36 42 dc2010a F02 Figure 2. Temperature Rising vs Input Voltage Quick Start Procedure Demonstration circuit 2010A is easy to set up to evaluate the performance of the LT8612. Refer to Figure 3 for proper measurement equipment setup and follow the procedure below: NOTE. When measuring the input or output voltage ripple, care must be taken to avoid a long ground lead on the oscilloscope probe. Measure the input or output voltage ripple by touching the probe tip directly across the VIN or VOUT and GND terminals. See Figure 4 for the proper scope technique. 1.Place JP1 on GND position. 2.With power off, connect the input power supply to VIN and GND. 3.With power off, connect the load from VOUT to GND. 4.Turn on the power at the input. 2 NOTE. Make sure that the input voltage does not exceed 42V. 5.Check for the proper output voltage (VOUT = 5V). NOTE. If there is no output, temporarily disconnect the load to make sure that the load is not set too high or is shorted. 6.Once the proper output voltage is established, adjust the load within the operating ranges and observe the output voltage regulation, ripple voltage, efficiency and other parameters. 7.An external clock can be added to the SYNC terminal when SYNC function is used (JP1 on the SYNC position). Please make sure that RT should be chosen to set the LT8612 switching frequency equal to or below the lowest SYNC frequency. See the data sheet section Synchronization. dc2010afa DEMO MANUAL DC2010A Quick Start Procedure Figure 3. Proper Measurement Equipment Setup Figure 4. Measuring Output Ripple dc2010afa 3 DEMO MANUAL DC2010A Parts List ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components 1 1 C2 CAP., X5R, 10µF, 50V, 10% 1210 MURATA, GRM32ER61H106KA12L 2 1 C8 CAP., X7R, 0.1µF, 25V, 10% 0603 MURATA, GRM188R71E104KA01D 3 1 C5 CAP., C0G, 10pF, 25V, 5% 0603 AVX, 06033A100JAT2A 4 1 C6 CAP., X5R, 100µF, 10V, 20% 1210 SAMSUNG, CL32A107MPVNNNE 5 2 C7, C9 CAP., X7R, 1.0µF, 25V, 10% 0603 MURATA, GRM188R71E105KA12D 6 2 C4, C15 CAP., X7R, 0.1µF, 50V, 10% 0402 TDK, C1005X7R1H104K 7 1 L1 IND., 3.3µH, IHLP2525EZ-01 VISHAY, IHLP2525EZER3R3M01 8 2 R1, R3 RES., CHIP., 100k, 1/10W, 1% 0603 VISHAY, CRCW0603100KFKEA 9 1 R2 RES., CHIP., 60.4k, 1/10W, 1% 0603 VISHAY, CRCW060360K4FKEA 10 1 R4 RES., CHIP., 1M, 1/10W, 1% 0603 VISHAY, CRCW06031M00FKEA 11 1 R5 RES., CHIP., 243k, 1/10W, 1%, 0603 VISHAY, CRCW0603243KFKEA 12 1 U1 IC, REGULATOR, 28-QFN, UDE LINEAR TECH., LT8612EUDE#PBF Additional Demo Board Circuit Components 1 1 C1 CAP., ALUM 22µF, 63V SUN ELECT., 63CE22BS 2 2 C3, C10 CAP., X5R, 10µF, 50V, 10% 1210 MURATA, GRM32ER61H106KA12L 3 1 C14 CAP., X7R, 0.1µF, 50V, 10% 0402 TDK, C1005X7R1H104K 4 0 C11 (OPT) CAP., 0603 5 1 L2 FERRITE BEAD 100Ω 8A SMD 1812 WURTH, 74279226101 6 1 L3 IND., 6.8µH, IHLP3232DZ-11 VISHAY, IHLP3232DZER6R8M11 7 0 R6 (OPT) RES., 0402 8 1 R7 RES., CHIP., 0Ω, 1/10W, 1%, 0603 VISHAY, CRCW06030000Z0EA Hardware: For Demo Board Only 1 10 E1-E10 TESTPOINT, TURRET, 0.094" MILL-MAX, 2501-2-00-80-00-00-07-0 2 1 JP1 HEADER, 3 PIN 0.079" SINGLE ROW SULLINS, NRPN031PAEN-RC 3 1 XJP1 SHUNT, 0.079" CENTER SAMTEC, 2SN-BK-G 4 4 MH1-MH4 STAND-OFF, NYLON 0.50" TALL KEYSTONE, 8833(SNAP ON) 4 dc2010afa VEMI TR/SS GND SYNC EN/UV GND E10 E7 E9 E5 E6 E2 E1 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. JP1 1 2 3 C3 10uF 50V 1210 L2 1812 WE 74279226101 SYNC GND SUNCON 63CE22BS 22uF 63V + C1 C7 1uF 25V C8 0.1uF C15 0.1uF 0402 C10 10uF 50V 1210 L3 6.8uH IHLP3232DZER6R8M11 VIN C2 10uF 50V 1210 1. ALL RESISTORS ARE 0603. ALL CAPACITORS ARE 0603. NOTES: UNLESS OTHERWISE SPECIFIED C14 0.1uF 50V 0402 VIN R2 60.4k 700KHz R6 OPT R1 100K 8 9 10 3 2 21 1 4 5 6 7 PGND PGND PGND RT TR/SS INTVCC SYNC EN/UV VIN VIN VIN U1 LT8612EUDE GND GND GND GND 11 12 13 14 GND 29 FB PG BIAS SW SW SW SW SW BST NC NC NC NC 25 26 27 28 VIN 5.8V - 42V 24 23 22 15 16 17 18 19 20 0 R7 L1 3.3uH R5 243k 10pF C5 1Meg R4 100K R3 IHLP2525EZER3R3M01 C4 0.1uF 0402 * E8 E4 E3 PG GND VOUT 5V / 6A * SEE DEMO MANUAL C9 1uF C11 OPT C6 100uF 10V 1210 VOUT DEMO MANUAL DC2010A Schematic Diagram dc2010afa 5 DEMO MANUAL DC2010A 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 6 dc2010afa Linear Technology Corporation LT 0915 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 2014