DEMO MANUAL DC2565A LT8607 42V, 0.75A Micropower Synchronous Step-Down Regulator Description Demonstration Circuit 2565A is a 42V, 0.75A micropower synchronous step-down regulator featuring the LT®8607. The demo board is designed for 5V output from a 5.5V to 42V input. The wide input range allows a variety of input sources, such as automotive batteries and industrial supplies. The LT8607 is a compact, high efficiency, high speed synchronous monolithic step-down switching regulator that consumes less than 3μA of quiescent current when output is regulated at 5V. Top and bottom power switches, compensation components and other necessary circuits are inside of the LT8607 to minimize external components and simplify design. The demo board has an EMI filter installed. The radiated EMI performances of the board (with EMI filter) are shown in Figure 2 and Figure 3. The red lines in Figure 2 and Figure 3 are CISPR25 Class 5 peak limit. To use the EMI filter, the input should be tied to VEMI, not VIN. An inductor L2, which is a 0Ω jumper on the board by default now, can be added in the EMI filter to further reduce the conducted emission. The SYNC pin on the demo board is grounded by default for low ripple Burst Mode® operation. Move JP1 to PULSE SKIPPING position can change the operation mode to pulse-skipping operation. Once JP1 is on SPREAD SPECTRUM position, VCC is applied to the SYNC pin for low EMI spread spectrum operation. To synchronous to an external clock, move JP1 to SYNC and apply the external clock to the SYNC turret. Figure 1 shows the efficiency of the circuit. Design files for this circuit board are available at http://www.linear.com/demo/DC2565A Performance Summary The LT8607 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 DC2565A. L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks of Analog Devices, Inc. All other trademarks are the property of their respective owners. Specifications are at TA = 25°C SYMBOL PARAMETER CONDITIONS MIN VIN Input Voltage Range 5.5 VOUT Output Voltage 4.8 IOUT Maximum Output Current 0.75 fSW Switching Frequency 1.85 EFE Efficiency at DC VIN = 12V, IOUT = 0.75A TYP MAX UNITS 42 V 5 5.2 V 2 2.15 MHz A 92.4 % dc2565af 1 DEMO MANUAL DC2565A Quick Start Procedure DC2565A is easy to set up to evaluate the performance of the LT8607. Refer to Figure 4 for proper measurement equipment setup and follow the procedure below: 5. Once the proper output voltage is established, connect a variable load capable of sinking 0.75A at 5V to the output terminals VOUT and GND. Set the current for 0A. NOTE: When measuring the input or output voltage ripple, care must be taken to avoid a long ground lead on the oscilloscope probe. See Figure 5 for the proper scope technique. a. If efficiency measurements are desired, an ammeter can be put in series with the output load in order to measure the DC2565A’s output current. b. A voltmeter can be placed across the output terminals in order to get an accurate output voltage measurement. 1. Set an input power supply that is capable of 42V/0.75A. Then turn off the supply. 2. With power off, connect the supply to the input terminals VIN and GND. 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. 3. Turn on the power at the input. NOTE: Make sure that the input voltage never exceeds 42V. 4. Check for the proper output voltage of 5V. Turn off the power at the input. 7. Once the proper output voltage is established again, adjust the load and/or input within the operating range and observe the output voltage regulation, ripple voltage, efficiency and other desired parameters. 8. An external clock can be added to the SYNC terminal when SYNC function is used (JP1 on the SYNC position). Please ensure that the chosen RT sets the LT8607 switching frequency to equal or below the lowest SYNC frequency. See the Synchronization section in the data sheet. 100 95 90 EFFICIENCY 85 80 75 70 65 60 VIN = 12V VIN = 24V 55 50 0 0.15 0.3 0.45 IOUT (A) 0.6 0.75 DC2565A F01 Figure 1. Efficiency vs Load Current at 2MHz Switching Frequency 2 dc2565af DEMO MANUAL DC2565A Quick Start Procedure 50 40 40 35 30 25 20 15 10 5 CLASS 5 PEAK LIMIT FIXED FREQUENCY SPREAD SPECTRUM MODE 0 –5 –10 0 100 200 300 HORIZONTAL POLARIZATION PEAK DETECTOR 45 AMPLITUDE (dBuV/m) AMPLITUDE (dBuV/m) 50 VERTICAL POLARIZATION PEAK DETECTOR 45 400 500 600 700 800 900 35 30 25 20 15 10 5 CLASS 5 PEAK LIMIT FIXED FREQUENCY SPREAD SPECTRUM MODE 0 –5 –10 1000 0 100 200 300 400 500 600 700 800 900 1000 FREQUENCY (MHz) FREQUENCY (MHz) DC2565A F03 DC2565A F02 Figure 2. LT8607 Demo Circuit EMI Performance in CISPR25 Radiated Emission Test, Antenna Polarization: Vertical (VIN = 14V, VOUT = 5V, IOUT = 0.75A, 2MHz Switching Frequency) Figure 3. LT8607 Demo Circuit EMI Performance in CISPR25 Radiated Emission Test, Antenna Polarization: Horizontal (VIN = 14V, VOUT = 5V, IOUT = 0.75A, 2MHz Switching Frequency) Figure 4. Proper Measurement Equipment Setup VOUT GND Figure 5. Measuring Output Ripple dc2565af 3 DEMO MANUAL DC2565A Parts List ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components 1 1 C2 CAP., X7R, 4.7µF, 50V, 10% 1206 MURATA, GRM31CR71H475K 2 1 C4 CAP., X7R, 0.22µF, 16V, 10%, 0603 MURATA, GRM188R71C224KA01D 3 1 C5 CAP., C0G, 10pF, 25V, 5%, 0603 AVX, 06033A100JAT2A 4 1 C6 CAP., X7R, 22µF, 10V, 10%, 1206 MURATA, GRM31CR71A226KE15L 5 1 C7 CAP., X7R, 1.0µF, 25V, 10%, 0603 MURATA, GRM188R71E105KA12D 6 1 C8 CAP., X7R, 0.01µF, 16V, 10%, 0603 MURATA, GRM188R71C103KA01D 7 1 L1 IND., 3.3µH WURTH ELECTRONICS, 74438336033 8 1 R2 RES., CHIP, 18.2k, 1/10W, 1%, 0603 VISHAY, CRCW060318K2FKEA 9 1 R3 RES., CHIP, 49.9k, 1/10W, 1%, 0603 VISHAY, CRCW060349K9FKEA 10 2 R1, R4 RES., CHIP, 1M, 1/10W, 1%, 0603 VISHAY, CRCW06031M00FKEA 11 1 R5 RES., CHIP, 187k, 1/10W, 1%, 0603 VISHAY, CRCW0603187KFKEA 12 1 U1 IC, REGULATOR, MSE10 LINEAR TECH., LT8607EMSE#PBF Additional Demo Board Circuit Components 1 1 C1 CAP., ALUM 22µF 63V SUN ELECT, 63CE22BS 2 2 C3, C10 CAP., X7R, 4.7µF, 50V, 10% 1206 MURATA, GRM31CR71H475K 3 1 C9 CAP., X7R, 4.7µF, 16V, 10%, 0805 MURATA, GRM21BR71C475K73L 4 1 C11 CAP., X7R, 1µF, 50V, 10%, 0805 MURATA, GRM21BR71H105KA12L 5 2 C12, C13 CAP., X7R, 0.1µF, 50V, 10%, 0603 MURATA, GRM188R71H104KA93D 6 1 FB1 FERRITE BEAD 0805 TDK, MPZ2012S331AT000 7 1 L2 RES., CHIP, 0Ω, 3/4W, 2010 VISHAY, CRCW20100000Z0EF 8 0 R6 (OPT.) RES., 0603 Hardware: For Demo Board Only 4 1 9 E1-E9 TESTPOINT, TURRET, 0.094" MILL-MAX, 2501-2-00-80-00-00-07-0 2 1 E10 (OPT.) TESTPOINT, TURRET, 0.094" 3 1 JP1 DOUBLE ROW HEADER 2 × 4 0.079" WURTH ELECTRONICS, 62000821121 4 1 XJP1 SHUNT, 0.079" CENTER WURTH ELECTRONICS, 60800213421 5 4 MH1-MH4 STAND-OFF, NYLON 0.50" TALL WURTH ELECTRONICS, 702935000 dc2565af 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 GND VEMI 5.5V - 42V VIN 5.5V - 42V E2 E1 E10 5 E9 E7 VCC E5 E6 C12 0.1µF 50V 4 6 8 5 7 2 3 1 JP1 C3 4.7µF 50V 1206 C1 22µF + 63V SUNCON 63CE22BS BURST PULSE SKIPPING SPREAD SPECTRUM SYNC C10 4.7µF 50V 1206 1. ALL RESISTORS ARE 0603. ALL CAPACITORS ARE 0603. 4 NOTES: UNLESS OTHERWISE SPECIFIED GND TR/SS SYNC EN/UV C11 1µF 50V 0805 FB1 L2 MPZ2012S331AT000 0 2010 4 C7 1µF C2 4.7µF 50V 1206 C8 0.01µF VCC C13 0.1µF 50V R2 18.2k (2MHz) R6 (Opt) R1 1.00M 3 4 7 3 5 10 9 3 RT TR/SS VCC SYNC EN/UV VIN U1 LT8607EMSE GND 11 D 5 FB PG SW BST 6 8 2 1 L1 3.3µH 2 R5 187k 49.9k R3 10pF C5 1.00M R4 74438336033 C4 0.22µF 2 VOUT C6 22µF 10V 1206 1 1 E8 E4 C9 E3 4.7µF 16V 0805 PG GND VOUT 5V /0.75A A B C D DEMO MANUAL DC2565A Schematic Diagram dc2565af 5 DEMO MANUAL DC2565A 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 dc2565af LT 0517 • PRINTED IN USA LINEAR TECHNOLOGY CORPORATION 2017