LT8609 LINER | Alldatasheet
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DESCRIPTION
42V, 2A Micropower Synchronous Step-Down Regulator Demonstration circuit 2195B is a 42V, 2A micropower synchronous step-down regulator featuring the LT8609/ LT8609A. There are two assembly versions. DC2195B-A is for the LT8609A and DC2195B-B is for the LT8609. The difference is the LT8609A has slower edge speeds for improved EMI at the expense of a small efficiency loss. 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 sup- plies. The LT8609/LT8609A is a compact, high efficiency, high speed synchronous monolithic step-down switching regulator that consumes only 2.5μA of quiescent current when output is regulated at 5V. Top and bottom power switches, compensation components and other necessary circuits are inside of the LT8609 to minimize external components and simplify design. 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 L, L T , L TC, L TM, 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 spectrum operation. To synchronize 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. The demo board has an EMI filter installed. Under spread spectrum operation, the radiated EMI performances of the board (with EMI filter) are shown in Figures 2 and 3. The red lines in Figures 2 and 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. This board is suitable for a wide range of automotive, telecom, industrial, and other general purpose applications. The LT8609/LT8609A data sheet gives a complete descrip tion of the part, operation and application information. The data sheet must be read in conjunction with this demo manual for DC2195B. Design files for this circuit board are available at http://www.linear.com/demo/DC2195B Specifications are at TA = 25°C SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS VIN Input Voltage Range 5.5 42 V VOUT Output Voltage 4.8 5 5.2 V IOUT Maximum Output Current 2 A fSW Switching Frequency 1.85 2 2.15 MHz EFE (LT8609A) Efficiency for DC2195B-A VIN = 12V, IOUT = 1A 92.1 % EFE (LT8609) Efficiency for DC2195B-B VIN = 12V, IOUT = 1A 92.9 %
- Set an input power supply that is capable of 42V/2A.
- With power off, connect the supply to the input terminals
- Turn on the power at the input.
NOTE: Make sure that the input voltage never exceeds 42V.
- Check for the proper output voltage of 5V. Turn off the
- Once the proper output voltage is established, connect
terminals VOUT and GND. Set the current for 0A. measure the DC2195B’s output current. in order to get an accurate output voltage measurement.
- Turn on the power at the input.
load to make sure that the load is not set too high.
- Once the proper output voltage is again established,
age, efficiency and other desired parameters.
- An external clock can be added to the SYNC terminal
Figure 1. Efficiency vs Load Current at 12V Input 2MHz Switching Frequency
Figure 2. LT8609A Demo Circuit EMI Performance in CISPR25 Radiated Emission Test (VIN = 14V, VOUT =
Figure 3. LT8609 Demo Circuit EMI Performance in CISPR25 Radiated Emission Test (VIN = 14V, VOUT = 5V,
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 AVX, 0603YC224KAT2A 3 1 C5 CAP., C0G, 10pF, 25V, 5%, 0603 AVX, 06033A100JAT2A 4 1 C6 CAP., X7R, 47µF, 10V, 10%, 1210 MURATA, GRM32ER71A476KE20L 5 1 C7 CAP., X7R, 1.0µF, 25V, 10%, 0603 MURATA, GRM188R71E105KA12D 6 1 C8 CAP., X7R, 0.01µF, 16V, 10%, 0603 AVX, 0603YC103KAT2A 7 1 L1 IND., 2.2µH COILCRAFT, XFL4020-222MEC 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 DC2195B-A Version Specific Components 1 1 U1 IC, REGULATOR, MSE10 LINEAR TECH., LT8609AEMSE#PBF DC2195B-B Version Specific Components 1 1 U1 IC, REGULATOR, MSE10 LINEAR TECH., LT8609EMSE#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 TDK, C2012X7R1H105K 5 2 C12, C13 CAP., X7R, 0.1µF, 50V, 10%, 0603 MURATA, GRM188R71H104KA93D 6 1 FB1 FERRITE BEAD 0805 TDK, MPZ2012S221A 7 1 L2 RES., CHIP, 0Ω, 3/4W, 2010 VISHAY, CRCW20100000Z0EF 8 0 R6 (OPT.) RES., 0603 Hardware: For Demo Board Only 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" SULLINS NRPN042PAEN-RC 4 1 XJP1 SHUNT, 0.079" CENTER SAMTEC 2SN-BK-G 5 4 MH1-MH4 STAND-OFF, NYLON 0.50" TALL KEYSTONE, 8833 (SNAP ON)
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 representa- tion that the interconnection of its circuits as described herein will not infringe on existing patent rights. SCHEMATIC DIAGRAM D D C C B B A A ALL CAPACITORS ARE 0603. NOTES: UNLESS OTHERWISE SPECIFIED 1. ALL RESISTORS ARE 0603. SUNCON 63CE22BS (2MHz) SYNC SPREAD SPECTRUM PULSE SKIPPING BURST FOR ASSEMBLY VERSIONS* U1 DC2195B-A LT8609AEMSE DC2195B-B LT8609EMSE VOUT VCC VCC 18.2k E6EN/UV SYNC GND 2.2µH XFL4020-222MEC 22µF 63V 1.00M 47µF 10V 1210 TR/SS C11 1µF 50V 0805 0.01µF 0.22µF C10 4.7µF 50V 1206 49.9k PG 1µF (Opt) VOUT 5V / 2A JP1 1 2 GND 0 2010 1.00M 187k C5 10pF VEMI 5.5V - 42V 4.7µF 50V 1206 C13 0.1µF 50V 4.7µF 50V 1206 FB1 U1 * VIN9 EN/UV10 SYNC5 VCC3 TR/SS7 RT4 FB 6 PG 8 SW 2 BST 1 GND11 C12 0.1µF 50V 4.7µF 16V 0805 GND E10 VIN 5.5V - 42V
DEMO MANUAL DC2195B Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear .com LINEAR TECHNOLOGY CORPORATION 2016 LT 0216 REV B • PRINTED IN USA DEMONSTRATION BOARD IMPORTANT NOTICE Linear Technology Corporation (LT C) 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 ONL Y and is not provided by LT C 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 LT C 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. LT C assumes no liability for applications assistance, customer product design, software performance, or infringement of patents or any other intellectual property rights of any kind. LT C 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 LT C applica- tion engineer. Mailing Address: Linear Technology 1630 McCarthy Blvd. Milpitas, CA 95035 Copyright © 2004, Linear Technology Corporation