LT3651EUHE-4.2 LINER

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LT3651EUHE-4.2/-4.1 4A High Voltage Li-Ion Battery Charger Demonstration circuit 1362A-A/1362A-B is a 4A high voltage Li-Ion battery charger featuring the LT®3651EUHE-4.2/ LT3651EUHE-4.1. 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 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 signal if the battery doesn’t respond 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 Input Voltage Range 6.5V to 32V VOUT 2.9V to 4.24V (–A)/2.7V to 4.14V (–B) Output Float Voltage (Constant Voltage Mode) 4.2V (–A)/4.1V (–B) Output Current Limit ILIM 4A Specifications are at TA = 25°C OPERATING PRINCIPLE LT3651 is a complete Li-Ion battery charger, addressing wide input voltage (6.5V 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, constant- voltage (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 (syn- chronous) 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 moni- tored 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.

Charge termination can occur when charge current de- creases to one-tenth of the programmed maximum charge current (C/10 termination). Alternately, termination can be timer based through the use of an internal program- mable 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. Once charging is terminated and the LT3651 is not ac- tively 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. 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 Figure 1. Efficiency and Power Loss vs VIN Demonstration circuit 1362A-A/1362A-B is easy to set up to evaluate the performance of the LT3651EUHE-4.2/ LT3651EUHE-4.1. 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 battery temperature moves outside the safe charging range of 0°C to 40°C the charging cycle suspends and signals a fault condition. 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. QUICK START PROCEDURE 2. Turn on PS2 and slowly increase the voltage to 2.7V while monitoring the current into the BAT pin. If the current is less than 5mA, turn on PS1. Increase the voltage on PS1 to 4V while monitoring the input current. If the current is less than 5mA, increase PS1 to 12V. 3. Verify that the battery charging current, IBAT is between 400mA and 600mA. The CHRG LED and ACPR LED should be on and the FAUL T LED should be off. VIN (V) EFFICIENCY (%) POWER LOSS (W) 15 25 DC1362ab F01 3.2 3.6 4.0 4.4 2.8 2.4 2.0 10 20 30 32 VBAT = 3.9 EFF PLOSS

  1. Increase PS2 until VBAT is 3.6V. Verify the input cur-
  2. Increase PS2 until VBAT is 4.25V. Verify the battery

CHRG LED and ACPR LED are off.

  1. Decrease PS2 until VBAT is 3.9V. Verify the battery cur-
  2. Decrease PS2 until VBAT is 3.6V. Connect a 10k resistor
  3. Set JP1 to SHDN. Verify the charging current IBAT is
  4. Set JP1 to RUN. Connect a jumper from the NTC pin to
  5. Remove the jumper from NTC to ground. Verify the
  6. Turn on LOAD1 and set to 1A. Verify the voltage VSYSTEM
  7. Turn off PS1, PS2 and LOAD1.

Figure 2. Proper Measurement Equipment Setup THEY ARE CONNECTED TO ON THIS DIAGRAM AND ANY INPUT, OR OUTPUT, LEADS SHOULD BE TWISTED PAIR.

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 3.3µH 20% 8.0A, 9mΩ 7mm × 7mm WURTH, 744314330 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, 44.2k, 1/16W, 1%, 0402 VISHAY, CRCW040244K2FKED 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 (-A VERSION) U1 (-B VERSION) 4A HIGH VOL TAGE Li-ION BATTERY CHARGER LINEAR TECHNOLOGY, LT3651EUHE-4.2 LINEAR TECHNOLOGY, LT3651EUHE-4.1 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, L TST-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)

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

Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear .com  LINEAR TECHNOLOGY CORPORATION 2012 LT 0213 REV A • 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