DEMO MANUAL DCA Description LT871 Synchronous Four-Quadrant Converter Demonstration circuit A is a synchronous fourquadrant converter featuring the LT 871 switching controller. The LT871 can regulate to positive, negative, or zero volts when configured as a four-quadrant topology. The DCA regulates from a 1V to 1V input source to an adjustable output voltage from positive 5V to negative 5V with a 5A maximum current rating, and operates at khz switching frequency. The LT871 incorporates a power good feature to let the user know if the output voltage is within its target regulation voltage. The LT871 has an output voltage control (CTRL) pin which sets the output voltage. The DCA has a jumper to select the CTRL pin voltage source from either externally (EXT) or internally (INT). If selected internally, the output voltage can be set to +5V or 5V. If selected externally, the output voltage can vary between positive 5V and negative 5V, following a.1v 1V CTRL signal with high bandwidth. The LT871 data sheet gives a complete description of the part, operation and application information. The data sheet must be read in conjunction with this quick start guide for demo circuit A. Design files for this circuit board are available at http://www.linear.com/871 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. Performance Summary Specifications are at T A = 5 C PARAMETER CONDITIONS MIN TYP MAX UNITS Input Voltage 1 1 1 V Positive Output Voltage (Max) V IN = 1V 1V.85 5 5.15 V Negative Output Voltage (Max) V IN = 1V 1V.85 5 5.15 V Maximum Output Current 5 A Positive Output Voltage Ripple V IN = 1V 1V, V OUT = 5V, I OUT = 5A (MHz BW) 5 mv P-P Negative Output Voltage Ripple V IN = 1V 1V, V OUT = 5V, I OUT = 5A (MHz BW) 5 mv P-P Typical Switching Frequency khz Efficiency V IN = 1V, V OUT = 5V, I OUT = 5A 89 % V IN = 1V, V OUT = 5V, I OUT = 5A 8 % Figure 1. DCA Connection Diagram dcaf 1
DEMO MANUAL DCA Quick Start Procedure Demonstration circuit A is easy to set up to evaluate the performance of the LT871. Refer to Figure 1 for proper measurement equipment setup and follow the procedure below: 1. With the power off, connect the input power supply to the board through V IN and PGND terminals. Connect the load to the terminals V OUT and PGND on the board. Make sure that the input power supply has sufficient current rating at minimum input voltage for the required output load.. Turn on the power at the input. NOTE: Make sure that the input voltage does not exceed 1V.. Check for the proper output voltages. The output should be regulated at +5.V (±%). If there is no output, temporarily disconnect the load to make sure that the load is not set too high.. Once the proper output voltage is established, adjust the input voltage and load current within the operating range and observe the output voltage regulation, ripple voltage, efficiency and other parameters. NOTE: When measuring the input or output voltage ripples, 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 V IN and PGND, or V OUT and PGND terminals. See Figure for proper scope probe technique. I IN + I OUT + + + + V POWER IN SUPPLY V OUT DCA F1 Figure 1. Proper Measurement Equipment Setup dcaf
DEMO MANUAL DCA Quick Start Procedure INPUT OR OUTPUT CAPACITOR Figure. Proper Scope Probe Placement for Measuring Input or Output Ripple 1 95 9 EFFICICY (%) 85 8 75 7 65 6 55 5.5 V IN = 1V, V O = +5V V IN = 1V, V O = +5V V IN = 1V, V O = +5V V IN = 1V, V O = 5V V IN = 1V, V O = 5V V IN = 1V, V O = 5V 1. 1.5..5..5..5 5. OUTPUT CURRT (A) DCA F Figure. Typical Efficiency Curve V CTRL.5V/DIV V OUT 5V/DIV 5µs/DIV DCA F Figure. Output Voltage Varies Between 5V and +5V, Following an Externally Controlled.1V to 1V, 1kHz Sinusoidal Voltage Source dcaf
DEMO MANUAL DCA Parts List ITEM QTY REFERCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components 1 CIN1, CIN, CIN, CIN CAP., X5R, µf,, 1%, MURATA, GRMER61E6KE15L 6 C1, C, C, C, C, C1 CAP., X5R, µf,, 1%, MURATA, GRMER61E6KE15L CO1, CO CAP., X5R, 1µF, 1V, %, MURATA, GRMER61A17MEK C7, C8, C9 CAP., X7R,.µF,, 1%, 85 MURATA, GRM1BR71E5KA7L 5 1 C1 CAP., X7R,.68µF,, 1%, 6 TDK, C168X7R1E68K8AB 6 1 C11 CAP., X7R,.68µF,, 1%, 6 MURATA, GRM188R71E68KA1D 7 1 C1 CAP., X7R,.1µF,, 1%, 6 MURATA, GRM188R71E1KA1D 8 1 C1 CAP., X7R, 1pF,, 1%, 6 AVX, 6C11KATA 9 1 C15 CAP., X7R,.1µF, 16V, 1%, 6 MURATA, GRM188R71C1KA1D 1 1 L1 INDUCTOR, 15µH Coilcraft, XAL151-15 11 1 L INDUCTOR, 15µH Coilcraft, XAL11-15 1 1 MN1 N-CH FET, PG-TDSON-8 INFINEON, BSCN6NS 1 1 MP1 P-CH FET, DPAK FAIRCHILD, FDD11 1 1 R1 RES., SSE, 7 mω, 1%, RL7W SUSUMU, RL7WT-R7-F 15 1 R RES., SSE, mω, 1%, RL7W SUSUMU, RL7WT-R-F 16 6 R, R, R5, R6, R9, R1 RES., Ω,.1W, 1%, 6 VISHAY, CRCW6ZEA 17 1 R7 RES., 1k, 1/1W, 1%, 6 VISHAY, CRCW61KFKEA 18 1 R8 RES., 57.6k, 1/1W, 1%, 6 VISHAY, CRCW657K6FKEA 19 1 R16 RES., 6.98k, 1/1W, 1%, 6 VISHAY, CRCW66K98FKEA 1 R19 RES., 18.7k, 1/1W, 1%, 6 VISHAY, CRCW618K7FKEA 1 R1, R15, R18 RES., 1k, 1/1W, 1%, 6 VISHAY, CRCW61KFKEA 1 R1 RES., 7.k, 1/1W, 1%, 6 VISHAY, CRCW67KFKEA 1 R1 RES., 1, 1/1W, 1%, 6 VISHAY, CRCW61RFKEA 1 R17 RES., 178k, 1/1W, 1%, 6 VISHAY, CRCW6178KFKEA 5 1 R19 RES., 18.7k, 1/1W, 1%, 6 VISHAY, CRCW618K7FKEA 6 1 R RES., 1Ω, 1/W, 1%, 16 VISHAY, CRCW161RFKEA 7 1 R RES., 1.78k, 1/1W, 1%, 6 VISHAY, CRCW61K78FKEA 8 1 U1 I.C., VOLTAGE REGULATOR, TSSOP LINEAR TECHNOLOGY, LT871EFE#PBF 9 1 FAB, PRINTED CIRCUIT BOARD DEMO CIRCUIT A Additional Demo Board Circuit Components 1 CO, CO () CAP., ION, C5, C6, C16, C17 () CAP., ION, 6 C18 () CAP., ION, 85 VR1 () TRIMMER, 5 R1 () RES.,, 6 6 MN () N-CH FET, ION, DPAK 7 MP () P-CH FET, ION, PG-TDSON-8 Hardware: For Demo Board Only 1 1 E1-E1 TESTPOINT, TURRET,.9" PbF MILL-MAX, 51---8---7-1 JP1 HEADER PIN.79 SINGLE ROW WURTH ELEKTRONIK, 6 111 1 1 JP HEADER PIN.79 DOUBLE ROW WURTH ELEKTRONIK, 6 6 11 1 XJP1, XJP SHUNT,.79" CTER WURTH ELEKTRONIK, 68 1 1 5 MH1-MH STAND-OFF, NYLON.5" KEYSTONE, 88 (SNAP ON) dcaf
DEMO MANUAL DCA Schematic Diagram E D C B A ISP ISN R.7 RL7W D D 1 PG MP PG-TDSON-8 5 MP1 FDD11 E5 L1 15uH XAL151-15 TG R PG C1 L 15uH XAL11-15 VOUT E6 VOUT ±5V / 5A 1V - 1V C C INTVCC NG B B E E E1 CIN1 µf CIN µf C7.µF 85 C8.µF 85 R18 1k R6 C11 68nF R NG C6 TG C16 R1 C C C C1 7.k 1% C uf C1 1nF C17 C18 85 R 1 16 ISP ISN C15 1nF R1 6 CO1 1µF 1V INTVCC R 1.78k 6 CO JP1 EXT 1 INT CO R19 18.7k 6 E1 VCTRL.1V - 1V AGND E9 E1 CIN µf C1 68nF R1. 1% RL7W C1 1pF uf 1 5 PGND E R7 1k R8 57.6k MN1 BSCN6NS 11 1 16 1 18 19 5 C5 BG CSN INTVCC PG RT SS 1 U1 LT871EFE GND 15 CSP GND 1 TG 1 ISP 7 ISN 6 CTRL BIAS INTVEE FB 1 17 8 9 VC C9.µF 85 R16 6.98k R9 R1 R1 1 R15 1k 6 1 5 6 JP +5V -5V E8 1 E1 E11 CIN µf R17 178k 1% R1 1k R5 MN DPAK uf VR1 CO 1µF 1V E7 PGND NOTE: UNLESS OTHERWISE SPECIFIED. 1. ALL RESISTORS AND CAPACITORS 6. A A E D C B A 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. dcaf 5
DEMO MANUAL DCA 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 GINEERING DEVELOPMT 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 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 EXTT OF THIS INDEMNITY, NEITHER PARTY SHALL BE LIABLE TO THE OTHER FOR ANY INDIRECT, SPECIAL, INCIDTAL, OR CONSEQUTIAL 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 16 McCarthy Blvd. Milpitas, CA 955 Copyright, Linear Technology Corporation 6 LT 115 PRINTED IN USA Linear Technology Corporation 16 McCarthy Blvd., Milpitas, CA 955-717 (8) -19 FAX: (8) -57 www.linear.com LINEAR TECHNOLOGY CORPORATION 15 dcaf