DEMO MANUAL DC1484A-A/-B LT3651EUHE-8.4/-8.2 4A High Voltage 2-Cell Li-Ion Battery Charger DESCRIPTION Demonstration circuit 1484A-A/-B is a 4A high voltage 2-Cell Li-Ion battery charger featuring the LT®3651EUHE-8.4/-8.2. The LT3651 is a complete, high power Li-Ion battery charger that can operate over a wide input voltage range. The charger is a constant-current, constant-voltage type with a maximum charge current of 4A that can be externally set. A precondition feature trickle charges a low voltage battery and bad battery detection provides a signal if the battery doesn’t respond PERFORMANCE SUMMARY to preconditioning. The LT3651EUHE is available in a 36-lead (5mm × 6mm) QFN surface mount package with two exposed thermal pads. Design files for this circuit board are available at http://www.linear.com/demo 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. Specifications are at TA = 25°C Input Voltage Range 12V to 32V VOUT 5.8V to 8.48V (–A)/5.4V to 8.28V (–B) Output Float Voltage (Constant Voltage Mode) 8.4V (–A)/8.2V (–B) Output Current Limit ILIM 4A OPERATING PRINCIPLE LT3651 is a complete Li-Ion battery charger, addressing wide input voltage (12V to 32V) and high charge current (up to 4A). High charging efficiency, as shown in Figure 1, is produced with a constant frequency, average current mode synchronous step-down switcher architecture. The charger includes the necessary circuitry to allow for programming and control of constant-current, constantvoltage (CC/CV) charging with both current only and timer termination. High charging efficiency is achieved by using a bootstrapped supply for low switch drop on the high side driver and a MOSFET for the low side (synchronous) switch. Maximum charge current is set with an external sense resistor in series with the inductor and is adjusted through the RNG/SS pin. The total system input current is monitored with an input sense resistor and is used to maintain constant input current by regulating battery charge current. It is adjusted through the ILIM pin. If the battery voltage is low, charge current automatically reduces to 15% of the programmed current to provide safe battery preconditioning. Once the battery voltage climbs above the battery precondition threshold, the IC automatically increases the maximum charging current to the full programmed value. dc1484aabf 1 DEMO MANUAL DC1484A-A/-B OPERATING PRINCIPLE After charging is complete, the input bias current lines connected to the battery are reduced to minimize battery discharge. The LT3651 contains provisions for a battery temperature monitoring circuit. Battery temperature is monitored by using an NTC thermistor located with the battery. If the The LT3651 contains two digital open-collector outputs, which provide charger status and signal fault conditions. These binary coded pins signal battery charging, standby or shutdown modes, battery temperature faults and bad battery faults. A precision undervoltage lockout is possible by using a resistor divider on the shutdown pin (SHDN). The input supply current is 17μA when the IC is in shutdown. 90 6.0 VBAT = 7.8V IBAT = 4A 89 EFFICIENCY 5.5 88 5.0 87 4.5 POWER LOSS (W) Once charging is terminated and the LT3651 is not actively charging, the IC automatically enters a low current standby mode in which supply bias currents are reduced to <85μA. If the battery voltage drops below 2.5% from the full charge float voltage, the LT3651 engages an automatic charge cycle restart. The IC also automatically restarts a new charge cycle after a bad battery fault once the failed battery is removed and replaced with another battery. battery temperature moves outside the safe charging range of 0°C to 40°C the charging cycle suspends and signals a fault condition. EFFICIENCY (%) Charge termination can occur when charge current decreases to one-tenth of the programmed maximum charge current (C/10 termination). Alternately, termination can be timer based through the use of an internal programmable charge cycle control timer. When using the timer termination, charging continues beyond the C/10 level to top off a battery. Charging typically terminates three hours after initiation. When the timer-based scheme is used, bad battery detection is also supported. A system fault is triggered if a battery stays in precondition mode for more than one-eighth of the total charge cycle time. POWER LOSS 86 85 4.0 10 3.5 15 20 VIN (V) 25 30 dc1484aab F01 Figure 1. Efficiency and Power Loss vs VIN QUICK START PROCEDURE Demonstration circuit 1484A-A/-B is easy to set up to evaluate the performance of the LT3651EUHE-8.4/-8.2. Using short twisted pair leads for any power connections, with all loads and power supplies off, refer to Figure 2 for the proper measurement and equipment setup. Follow the procedure below: 1. Jumper and power supply setting: JP1 = RUN PS1 = OFF JP2 = C/10 PS2 = OFF 2. Turn on PS2 and slowly increase the voltage to 5.4V while monitoring the current into the BAT pin. If the current is less than 5mA, turn on PS1. Increase the voltage on PS1 to 8V while monitoring the input current. If the current is less than 5mA, increase PS1 to 24V. 3. Verify that the battery charging current, IBAT is between 400mA and 600mA. The CHRG LED and ACPR LED should be on and the FAULT LED should be off. dc1484aabf 2 DEMO MANUAL DC1484A-A/-B QUICK START PROCEDURE 4. Increase PS2 until VBAT is 7.2V. Verify the input current IIN is between 1.4A and 1.7A, the battery current IBAT is between 3.75A and 4.45A and that the CHRG LED and ACPR LED are on. 5. Increase PS2 until VBAT is 8.5V. Verify the battery charging current IBAT is less than 5mA and that the CHRG LED and ACPR LED are off. 6. Decrease PS2 until VBAT is 7.8V. Verify the battery current IBAT is between 3.75A and 4.45A that the CHRG LED and ACPR LED are on. 7. Decrease PS2 until VBAT is 7.2V. Connect a 10k resistor from the RNG/SS pin to ground. Verify the charging current IBAT is between 1.7A and 2.0A. Verify the voltage VNTC on the NTC turret is between 1.6V and 1.9V and the voltage VRNG on the RNG/SS turret is between 450mV and 700mV. Remove the 10k resistor from the RNG/SS pin to ground + 8. Set JP1 to SHDN. Verify the charging current IBAT is less than 5mA and that the FAULT LED, CHRG LED and ACPR LED are off. 9. Set JP1 to RUN. Connect a jumper from the NTC pin to ground. Verify the charging current IBAT is less than 5mA and that the FAULT LED, CHRG LED and ACPR LED are on. 10. Remove the jumper from NTC to ground. Verify the charging current IBAT is between 3.75A and 4.45A and that the FAULT LED is off and the CHRG LED and ACPR LED are on. 11. Turn on LOAD1 and set to 1A. Verify the voltage VSYSTEM on the system voltage turret is approximately equal to VIN. 12. Turn off PS1, PS2 and LOAD1. – AM1 + + PS1 0V TO 40V SUPPLY VM1 – – + + – + LOAD 1 1A – – AM2 AM3 + + VM2 VM3 – – + .75Ω 25W PS2 0V TO 5V SUPPLY – dc1484aab F02 NOTE: ALL CONNECTIONS FROM EQUIPMENT SHOULD BE KELVIN CONNECTED DIRECTLY TO THE BOARD PINS WHICH THEY ARE CONNECTED TO ON THIS DIAGRAM AND ANY INPUT, OR OUTPUT, LEADS SHOULD BE TWISTED PAIR. Figure 2. Proper Measurement Equipment Setup dc1484aabf 3 DEMO MANUAL DC1484A-A/-B PARTS LIST ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER Required Circuit Components 1 1 C1 CAP., X7R, 1μF, 50V, 10%, 0805 MURATA, GRM21BR71H105KA12L 2 4 C3, C6, C11, C12 CAP., X7S, 10μF, 50V, 20%, 1210 TDK, C3225X7S1H106M 3 1 C4 CAP., X7R, 10μF, 10V, 10%, 0805 MURATA,GRM21BR71A106KE51L 4 3 C5, C7, C13 CAP., X5R, 0.68μF, 10V, 10%, 0402 MURATA, GRM155R61A684KE15D 5 1 C8 CAP., X5R, 100μF, 6.3V, 20%, 1210 TAIYO YUDEN, LMK325BJ107MM-T 6 1 D2 SMD, SCHOTTKY DIODE, SOT-23 CENTRAL SEMI, CMPSH1-4 TR 7 1 D6 DIODE, ZENER, 10V SOD-123 CENTRAL SEMI, CMHZ4697 8 1 L1 POWER INDUCTOR 6.5μH, 20%, 6.0A, 21.5mΩ WÜRTH, 744314650 9 1 Q1 MOSFET, PCHANNEL, 40V, 25mΩ, 1212-8 VISHAY, Si7611DN 10 1 R1 RES., CHIP, 0.015Ω, 1/2W, 1%, 1206 IRC, LRC-LR1206LF-01-R015-F 11 1 R4 RES., CHIP, 0.024Ω, 1/2W, 1%, 1206 IRC, LRC-LR1206LF-01-R024-F 12 2 R5, R12 RES., CHIP, 10k, 1/16W, 1%, 0402 VISHAY, CRCW040210K0FKED 13 1 R7 RES., CHIP, 64.9k, 1/16W, 1%, 0402 VISHAY, CRCW040264K9FKED 14 1 R8 RES., CHIP, 0.05Ω, 1/2W, 1%, 1206 IRC, LRC-LR1206LF-01-R050-F 15 1 R9 RES., CHIP, 147k, 1/16W, 1%, 0402 VISHAY, CRCW0402147KFKED 16 1 R13 RES., CHIP, 100k, 1/16W, 1%, 0402 VISHAY, CRCW0402100KFKED 17 1 U1 (DC1484A-A) U1 (DC1484A-B) 4A HIGH VOLTAGE 8.4V LI-ION BATTERY CHARGER 4A HIGH VOLTAGE 8.2V LI-ION BATTERY CHARGER LINEAR TECH.,LT3651EUHE-8.4 LINEAR TECH.,LT3651EUHE-8.2 Optional Electrical Components 1 1 C2 CAP, SMT, 22μF, 50V 20% SUNCON, 50CE22BS 2 2 C9, C10 CAP, CHIP, X7R, 0.022μF, ±10%, 16V, 0402 AVX, 0402YC223KAT2A 3 0 D1 SMD, SCHOTTKY, 5A, 40V DIODES INC, PDS540-13 4 1 D3 LED, RED PANASONIC, LNJ208R8ARA 5 2 D4, D5 LED, GREEN LITE-ON, LTST-C190KGKT 6 0 J1 HEADER, 3 PINS HIROSE ELECTRIC, DF3A-3P-2DSA 7 3 R2, R3, R10 RES, CHIP, 5.1k,1/4W, 5%, 1206 VISHAY, CRCW12065K10JNED 8 0 R6, R11 RES, CHIP, 20k, 1/16W, 1%, 0402 VISHAY, CRCW040220K0FKED Hardware for Demo Circuit 1 8 E1 TO E8 TESTPOINT, TURRET, 0.095" MILL-MAX, 2501-2-00-80-00-00-07-0 2 2 JP1, JP2 2MM SINGLE ROW HEADER, 3 PIN SAMTEC, TMM-103-02-L-S 3 2 JP1, JP2 SHUNT SAMTEC, 2SN-BK-G 4 4 MH1 TO MH4 STAND-OFF, NYLON 0.375" TALL (SNAP ON) KEYSTONE, 8832 (SNAP ON) dc1484aabf 4 GND E2 SHDN RUN Q1 Si7611DN R12 10k 1 3 JP1 2 R13 100k OPT R5 10K C/10 TIMER R2 5.1K 1206 C13 0.68uF D3 RED R9 147k R10 5.1K 1206 D5 GRN ACPR R6 20k 28 24 27 26 25 2 29 35 6 23 R11 20k OPT D4 GRN FAULT 36 C7 0.68uF R3 5.1K 1206 R7 64.9k CHRG 2 + R1 0.015 1206 JP2 D6 CMHZ4697 10V C2 22uF 50V 20% 1 3 RNG/SS GND GND RT ILIM TIMER SHDN CHRG FAULT ACPR CLP 30 CLN VIN VIN 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. C5 0.68uF 32 VIN 33 PIN 8 PIN 9 VIN * 37 GND 34 PIN 10 PIN 19 PIN 20 12V - 32V 21 GND 31 C12 10uF 50V 1210 U1 LT3651EUHE - 8.2 -B C1 1uF 50V 0805 LT3651EUHE - 8.4 3 4 5 11 7 38 12 13 14 15 16 17 L1 6.5uH 2 C11 10uF 50V 1210 8.2V 8.4V VFLOAT * R8 0.05 1206 WURTH 744314650 1 C3 10uF 50V 1210 -A U1* BAT SENSE BOOST SW SW SW SW SW SW SW SW SW C6 10uF 50V 1210 ASSY PIN 18 D1 PDS540 SW 22 NTC 1 SW E1 C8 100uF 10V 1210 20% R4 0.024 1206 C4 10uF 10V 0805 10% CMPSH1-4 D2 C9 0.022uF 16V C10 0.022uF 16V 1 2 3 GND 4A E8 RNG / SS NTC J1 (OPT) E6 DF3-3P-2DSA E7 BAT GND NTC-EXT GND SYSTEM LOAD BAT VFLOAT* E5 E4 E3 DEMO MANUAL DC1484A-A/-B SCHEMATIC DIAGRAM dc1484aabf 5 DEMO MANUAL DC1484A-A/-B 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 dc1484aabf 6 Linear Technology Corporation LT 0113 • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com © LINEAR TECHNOLOGY CORPORATION 2013