DEMO MANUAL DC2011A LT8613: 42V, 6A Micropower Synchronous Step-Down Regulator with Current Sense DESCRIPTION Demonstration Circuit 2011A is a 42V, 6A micropower synchronous step-down regulator with current sense featuring the LT®8613. 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 LT8613 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 LT8613 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. The DC2011A has output current limit set at 6A by default. The current limit can be moved to the input side for application where input supply current is limited. ICTRL and IMON on the board set and monitor the regulated current, respectively. Figure 1 shows the efficiency of DC2011A circuit. Figure 2 shows the LT8613 temperature rising on DC2011A 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 LT8613 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 DC2011A. The LT8613 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/DC2011A L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. PERFORMANCE SUMMARY Specifications are at TA = 25°C SYMBOL PARAMETER CONDITIONS VIN Input Supply Range VOUT Output Voltage IOUT Maximum Output Current fSW Switching Frequency EFE Efficiency at DC MIN TYP MAX 42 V 5 5.125 V 5.8 4.875 Derating Is Necessary for Certain VIN and Thermal Conditions 6 665 VIN = 12V , IOUT = 3A UNITS A 700 94 735 kHz % dc2011afa 1 DEMO MANUAL DC2011A QUICK START PROCEDURE Demonstration Circuit 2011A is easy to set up to evaluate the performance of the LT8613. 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. 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 LT8613 switching frequency equal to or below the lowest SYNC frequency. See the data sheet section “Synchronization”. 90 100 VIN = 12V 80 TEMPERATURE RISING (°C) 95 EFFICIENCY (%) 90 VIN = 24V 85 80 75 70 VOUT = 5V fSW = 700kHz SYNC = GND 65 60 0 1 4 3 2 LOAD CURRENT (A) 5 60 50 40 30 20 VOUT = 5V fSW = 700kHz 10 6 DC2011A G01 Figure 1. Efficiency vs. Load Current (Using VIN Terminal) 2 70 0 6 12 30 24 18 INPUT VOLTAGE (V) IOUT = 6A IOUT = 5.5A IOUT = 5A IOUT = 4.5A IOUT = 4A 36 42 DC2011A G2 Figure 2. Temperature Rising vs. Input Voltage dc2011afa DEMO MANUAL DC2011A QUICK START PROCEDURE Figure 3. Proper Measurement Equipment Setup VOUT GND Figure 4. Measuring Output Ripple dc2011afa 3 DEMO MANUAL DC2011A PARTS LIST ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER CAP., X5R, 10µF, 50V, 10% 1210 MURATA, GRM32ER61H106KA12L Required Circuit Components 1 1 C2 2 2 C4, C12 CAP., X5R, 0.1µF, 50V, 10% 0402 TDK, C1005X5R1H104K 3 1 C6 CAP., X5R, 100µF, 10V, 20% 1210 MURATA, GRM32ER61A107ME20L 4 2 C7, C11 CAP., X7R, 1.0µF, 25V, 10% 0603 MURATA, GRM188R71E105KA12D 5 1 C8 CAP., X7R, 0.1µF, 50V, 10% 0603 MURATA, GRM188R71H104KA93D 6 1 C9 CAP., C0G, 10pF, 50V, 5% 0603 MURATA, GRM1885C1H100JA01D 7 1 L1 IND, 3.3µH, IHLP2525EZ-01 VISHAY, IHLP2525EZER3R3M01 8 1 R1 RES., CHIP., 0Ω, 1/2W, 1% 1210 VISHAY, CRCW12100000Z0EA 9 1 R5 RES., CHIP., 0.008Ω, 1/2W, 1%, 2010 VISHAY, WSL20108L000FEA 10 2 R6, R7 RES., CHIP., 0Ω, 1/10W, 0603 VISHAY, CRCW06030000Z0EA 11 1 R8 RES., CHIP., 60.4k,1/10W, 1%, 0603 VISHAY, CRCW060360K4FKE 12 2 R9, R12 RES., CHIP., 100k,1/10W, 1%, 0603 VISHAY, CRCW0603100KFKEA 13 1 R10 RES., CHIP., 1M, 1/10W, 1%, 0603 VISHAY, CRCW06031M00FKEA 14 1 R11 RES., CHIP., 243k, 1/10W, 1%, 0603 VISHAY, CRCW0603243KFKEA 15 1 U1 IC, REGULATOR, 28-QFN, UDE LINEAR TECH., LT8613EUDE#PBF Additional Demo Board Circuit Components 1 1 C1 CAP., ALUM 22µF 63V SUNCON, 63CE22BS 2 2 C3, C10 CAP., X5R, 10µF, 50V, 10% 1210 MURATA, GRM32ER61H106KA12L 3 0 C5 (OPT) CAP., 0603 4 1 C15 CAP., X5R, 0.1µF, 50V, 10% 0402 TDK, C1005X5R1H104K 5 1 FB1 FERRITE BEAD 100Ω 8A SMD 1812 WÜRTH ELEKTRONIK, 74279226101 6 1 L2 IND., 6.8µH, IHLP3232DZ-01 VISHAY, IHLP3232DZER6R8M01 7 0 R2, R3, R4 (OPT) RES., 0603 8 1 R7 RES., CHIP., 0Ω, 1/10W, 1%, 0603 VISHAY, CRCW06030000Z0EA Hardware/Components (For Demo Board Only) 4 1 12 E1-E12 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) dc2011afa DEMO MANUAL DC2011A SCHEMATIC DIAGRAM D C B A E2 E1 VIN 5.8V - 42V E12 VEMI GND C15 0.1uF 50V 0402 5 5 FB1 74279226101 C3 10uF 50V 1210 E7 E6 E9 E5 E8 4 + C1 22uF 63V SUNCON 63CE22BS L2 6.8uH IHLP3232DZER6R8M01 C10 10uF 50V 1210 EN/UV SYNC GND IMON ICTRL TR/SS E11 SYNC GND NOTES: UNLESS OTHERWISE SPECIFIED 1. ALL RESISTORS ARE 0603. ALL CAPACITORS ARE 0603. 4 JP1 3 2 1 R1 R2 OPT 0 1210 R3 OPT C2 10uF 50V 1210 C7 1uF 25V ISN 3 R12 100k R4 OPT R8 60.4k U1 LT8613EUDE BST ICTRL ISN ISP SW SW SW SW SW INTVCC FB PG BIAS RT TR/SS IMON SYNC EN/UV 5 6 VIN 7 VIN VIN 4 1 27 28 21 2 3 8 9 PGND 10 PGND PGND 20 15 16 17 18 19 26 25 22 24 23 2 2 C4 0.1uF 0402 L1 3.3uH C5 OPT R10 0 R6 0 R7 1Meg C9 100k R9 IHLP2525EZER3R3M01 ISP ISN R11 243k 10pF R5 0.008 2010 VOUT 1 C6 100uF 10V 1210 1 * E3 PG GND * VOUT 5V / 6A SEE DEMO MANUAL C11 1uF E4 E10 D C B A dc2011afa 5 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. ISP C12 0.1uF 50V 0402 C8 0.1uF 3 11 12 GND 13 GND 14 GND GND 29 GND DEMO MANUAL DC2011A 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. 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