DEMO MANUAL DC1688A LT3652HVEDD 17.7V to 34V Input SLA 2A Battery Charger For Solar Power DESCRIPTION Demonstration circuit 1688A is a sealed-lead acid 2A battery charger for solar power applications featuring the LT3652HVEDD. The LT3652HV is a complete mid-power battery charger that can operate over a wide input voltage range. The charger employs a 3.3V battery voltage feedback reference that allows the voltage for charging to be adjusted up to 18V. The LT3652HV has an input voltage regulation loop which reduces charge current if the input falls below a programmed level, set with a resistor divider. The circuit provides constant-current/constant-voltage charging with a maximum charge current of 2A that is programmed by a current sense resistor. A precondition feature trickle charges a low voltage battery, and bad battery detection provides a signal if the battery doesn’t respond to preconditioning. The LT3652HVEDD is available in a 12-lead (3mm × 3mm) DFN surface mount package with an exposed pad. 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. PERFORMANCE SUMMARY Table 1. Typical Specifications (TA = 25°C) PARAMETER CONDITIONS VALUE Input Voltage Range 17.7V to 34V VBAT Charge/VBAT Float 14.3V to 14.5V/13.4V to 13.6V Output Charge/Float Voltage Constant Voltage Mode 14.4V/13.5V Output Current Limit ILIM VIN_REG Greater Than 2.7V 2A OPERATING PRINCIPLE LT3652HV is a complete monolithic mid-power battery charger, addressing high input voltage applications with solutions that require a minimum number of external components. The IC uses a 1MHz constant frequency, average current mode step-down architecture. The LT3652HV maximizes efficiency during charging cycles by using a bootstrapped supply to drive the internal power switch. Figures 1 and 2 display charger efficiency and input current for various input voltages and battery voltages. A precision threshold shutdown pin allows the incorporation of UVLO functionality using a simple resistor divider. The IC can also be put into a low-current shutdown mode, in which the input supply bias is reduced to only 15μA. The LT3652HV incorporates several degrees of charge current control freedom. The overall maximum charge current is set using an external inductor current sense resistor. The LT3652HV employs an input voltage regulation loop which reduces charge current if the input voltage falls below a programmed level, set with a voltage divider. This can be seen in Figure 3. When the LT3652HV is powered by a solar panel, the input regulation loop is used to maintain the panel at peak output power. The LT3652HV automatically enters a battery precondition mode if the sensed battery voltage is very low. In this mode, the charging current is reduced to 15% of the programmed maximum, as set by the inductor sense dc1688afa 1 DEMO MANUAL DC1688A OPERATING PRINCIPLE resistor, RSENSE. Once the battery voltage increases to the precondition threshold, the IC automatically increases maximum charging current to the full programmed value. DC1688A programs the output voltage to be 14.4V during charging and the 9.5V precondition threshold is internally set as a fraction of the programmed output voltage. The LT3652HV can use a charge current based ‘C/10’ termination scheme, which ends a charge cycle when the battery charge current falls to 1/10th the programmed maximum charge current. The LT3652HV also contains an internal charge cycle control timer, for timer-based termination. When using the internal timer, the IC combines C/10 detection with a programmable time constraint, during which the charging cycle can continue beyond the C/10 level. DC1688A programs a lower 13.5V float output voltage at the time the C/10 condition occurs. Use of the internal timer allows DC1688A to provide a float voltage to the battery until the charge cycle terminates because time elapses. The timer on DC1688A is programmed so the circuit can provide a float voltage all day, as may be needed by a solar panel application. When the timer-based scheme is used, the IC also supports “bad battery” detection, which 2.0 IBAT = 2A 1.8 1.6 INPUT CURRENT EFFICIENCY 85 80 Once charging is terminated and the LT3652HV is not actively charging, the IC automatically enters a low current standby mode where supply bias currents are reduced to < 100μA. If the battery voltage drops 2.5% from the fullcharge float voltage, the LT3652HV 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. The LT3652HV includes provisions for a battery temperature monitoring circuit. This feature monitors battery temperature during the charging cycle using a thermistor, and suspends charging and signals a fault condition if the battery temperature moves outside a safe charging range of 0°C to 50°C. The LT3652HV 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. 2.5 VIN = 12V VIN = 15V VIN = 24V 2.0 CHARGE CURRENT (A) 90 triggers a system fault if a battery stays in precondition mode for more than 1/8th of the total charge cycle time. 1.4 1.2 1.0 0.8 0.6 75 VIN = 12V VIN = 15V VIN = 24V 70 3.3 4.5 5.7 6.9 8.1 9.3 10.5 11.7 12.9 14.1 BATTERY VOLTAGE 0.4 1.5 1.0 0.5 0.2 0.0 3.3 4.5 5.7 6.9 8.1 9.3 10.5 11.7 12.9 14.1 BATTERY VOLTAGE 1688A F01 Figure 1. LT3652HV Efficiency 1688A F02 Figure 2. 2A Charge Current 0.0 17.5 17.6 17.7 17.8 17.9 18 18.1 18.2 18.3 INPUT VOLTAGE 1688A F03 Figure 3. Charge Current vs Input Voltage QUICK START PROCEDURE Demonstration circuit 1688A is easy to set up to evaluate the performance of the LT3652HVEDD. Using short twisted pair leads for any power connections, with all loads and power supplies off, refer to Figure 4 for the proper measurement and equipment setup. dc1688afa 2 DEMO MANUAL DC1688A QUICK START PROCEDURE Follow the procedure below: 1. Jumper and Power Supply Setting: JP1 = 1 JP4 = 1 JP2 = 0 PS1 = OFF JP3 = C/10 PS2 = OFF 2. Turn on PS2 and slowly increase the voltage until VBAT is 7.5V while monitoring the current into the BAT pin. If the current is less than 5mA, turn on PS1. Increase PS1 until VIN is 18V while monitoring the input current. 3. Verify the battery charging current is between 250mA and 350mA. The CHRG LED should be on and the FAULT LED should be off. 4. Increase PS2 until VBAT is 12.0V. Verify the input current is between 1.3A and 1.7A, the battery current is between 1.775A and 2.225A and that the CHRG LED is on. 5. Increase PS2 until VBAT is 14.8V. Verify the battery charging current is less than 5mA and that the CHRG LED is off. 6. Decrease PS2 until VBAT is 13.8V. Verify the battery charging current is less than 5mA and that the CHRG LED is off. 7. Decrease PS2 until VBAT is 12.0V. Verify the battery current is between 1.775A and 2.225A and that the CHRG LED is on. 8. Set JP1 to 0. Verify the charging current is less than 5mA and that the FAULT LED and the CHRG LED are off. 9. Set JP1 to 1. Connect a jumper from the NTC pin to ground. Verify the charging current is less than 5mA and that the FAULT LED and the CHRG LED are on. 10. Remove the jumper from NTC to ground. Verify the charging current is between 1.775A and 2.225A and that the FAULT LED is off and the CHRG LED is on. 11. Turn on LOAD1 and set to 1A. Verify the voltage, Vsystem, on the System Load terminal is approximately equal to VIN. Turn off LOAD1. Decrease PS1 to 14.0V. 12. Verify the battery charging current is less than 5mA and that the CHRG LED is off. 13. Increase PS1 to 18.5V. Verify the charging current is between 1.775A and 2.225A and that the CHRG LED is on. Set JP2 to 1. Decrease PS1 to 17.0V. 14. Set JP4 to 0. Setting JP4 to 0 turns off the charge current when VIN is less than 17.7V. Verify the battery charging current is less than 5mA and that the CHRG LED is off. 15. Increase PS1 to 19.0V. Verify the charging current is between 1.775A and 2.225A and that the CHRG LED is on. Set JP4 to 1. Set JP2 to 0. 16. Turn off PS1 and PS2. 1688a F04 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 4. Proper Measurement Equipment Setup for DC1688A dc1688afa 3 DEMO MANUAL DC1688A PARTS LIST ITEM QTY REFERENCEDESCRIPTION DESCRIPTION MANUFACTURER’S PART NUMBER MURATA, GRM32ER71H106KA88L Required Circuit Components: 1 1 C2 CAP., X7R, 10μF, 50V, 10%, 1210 2 1 C3 CAP., X7R, 1μF, 50V, 10%, 0805 MURATA, GRM21BR71H105KA12B 3 1 C5 CAP., SMT, 100μF, 20V, 20% SANYO, 20SVP100M 4 1 C6 CAP., X7R, 10μF, 25V, 10%, 1206 MURATA, GRM31CR71E106KA12L 5 1 C9 CAP., X5R, 4.7μF, 4V, 20%, 0402 MURATA, GRM155R60G475M 6 2 D1, D2 SMD, SCHOTTKY BARRIER RECTIFIER CENTRAL SEMI, CMSH3-40MA 7 1 D5 SMD, SCHOTTKY DIODE, SOT-23F CENTRAL SEMI, CMPSH1-4 8 1 D6 SMD, ZENER DIODE, 6.2V, SOT-23 CENTRAL SEMI, CMHZ4691TR 9 1 D8 SMD, SWITCHING DIODE, SOD323 VISHAY, 1N4148WS-V-GS08 10 1 L1 POWER INDUCTOR, 15μH, 20%, 3.5A COILCRAFT, MSS1038-153ML 11 1 R1 RES., CHIP, 1.33MEG, 1/16W, 1%, 0402 VISHAY, CRCW04021M33FKED 12 1 R4 RES., CHIP, 562K, 1/16W, 1%, 0402 VISHAY, CRCW0402562KFKED 13 2 R5, R6 RES., CHIP, 100K, 1/16W, 1%, 0402 VISHAY, CRCW0402100KFKED 14 1 R7 RES., CHIP, 0.05 OHM, 1/2W, 1%, 1206 SUSUMU, RL1632R-R050-F 15 1 R9 RES., CHIP, 174K, 1/16W, 1%, 0402 VISHAY, CRCW0402174KFKED 16 1 R10 RES., CHIP, 309K, 1/16W, 0.1%, 0603 SUSUMU, RG1608P-3093-B-T5 17 1 R11 RES., CHIP, 100K, 1/16W, 0.1%, 0603 SUSUMU, RG1608P-104-B-T5 18 1 R12 RES., CHIP, 1.00MEG, 1/16W, 1%, 0402 VISHAY, CRCW04021M00FKED 19 1 U1 SLA 2A BATTERY CHARGER FOR SOLAR POWER LINEAR TECHNOLOGY, LT3652HVEDD C1 CAP., SMT, 390μF, 50V, 20 SANYO, 50CE390BS Additional Demo Board Circuit Components: 1 1 2 2 C7, C8 CAP., CHIP, X7R, 0.022μF, ±10%, 16V, 0402 AVX, 0402YC223KAT2A 3 1 D3 LED, RED PANASONIC, LN208R8ARA 4 1 D4 LED, GREEN LITE-ON, LTST-C190KGKT 5 2 R2, R3 RES., CHIP, 5.1K,1/4W, 1%, 1206 VISHAY, CRCW12065K10FKEA 6 1 R8 RES., CHIP, 20,1/16W, 5%, 0402 VISHAY, CRCW040220R0JNED Optional Demo Board Circuit Components: 1 0 C4(OPT) CAP,. OPT, 0402 CUSTOMER SELECTABLE 2 0 D7(OPT) SMD, SCHOTTKY BARRIER RECTIFIER CENTRAL SEMI, CMSH3-40MA 3 0 D9(OPT) SMD, ZENER DIODE, 10V, SOT-23 CENTRAL SEMI, CMHZ4697 4 0 J1(OPT) HEADER, 3 PINS HIROSE ELECTRIC, DF3A-3P-2DSA 5 0 R13(OPT) RES., CHIP, 10K, 1/16W, 1%, 0402 VISHAY, CRCW040210K0FKED 6 0 R14(OPT) RES., CHIP, 100K, 1/16W, 1%, 0402 VISHAY, CRCW0402100KFKED 7 0 Q1(OPT) SMD, P-CHANNEL MOSFET, 40V, 82mΩ VISHAY, SI2319DS Hardware For Demo Board Only: 1 7 E1-E7 TESTPOINT, TURRET, .095" MILL-MAX, 2501-2-00-80-00-00-07-0 2 1 J1 HEADER, 3 PINS HIROSE ELECTRIC, DF3A-3P-2DSA 3 4 JP1-JP4 2mm SINGLE ROW HEADER, 3 PIN SAMTEC, TMM-103-02-L-S 4 4 JP1-JP4 SHUNT SAMTEC, 2SN-BK-G 5 4 STAND-OFF, NYLON, 0.625" TALL (SNAP ON) KEYSTONE, 8834 (SNAP ON) dc1688afa 4 GND E2 E1 3 1 R13 10k OPT 2 R14 100k OPT 1 JP2 0 1 UVLO 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. X 0 SHDN C1 390uF 50V 20% D9 CMHZ4697 10V OPT + 0 1 JP1 2 R1 1.33Meg D3 FAULT RED LED-LN R2 5.1K 1206 0 1 D4 CHRG GRN LED-LN TIMER C/10 JP2 2 R3 5.1K 1206 0 1 JP3 C9 4.7uF 4V 20% 2 R6 100K R5 100K 2 JP4 6 3 5 4 2 1 1.00Meg R12 TIMER SHDN FAULT CHRG VIN VIN_REG R4 562K D8 NTC VFB BAT SENSE BOOST 1N4148WS-V 13 GND SW 12 8 7 9 10 11 U1 LT3652HVEDD D5 R9 174k L1 15uH 2 R11 100K 0603 0.1% R10 309K 0603 0.1% TP2 D6 R7 0.05 1206 1/4W 6.2V CMSH3-40MA D2 + MSS1038-153ML 1 CMHZ4691 1 R8 20 TP1 OPT C4 CMPSH1-4 3 C3 1uF 50V 0805 C2 10uF 50V 1210 2 C5 100uF 20V 20% C6 10uF 25V 1206 10% C7 0.022uF 25V C8 0.022uF 25V CMSH3-40MA OPT D7 CUSTOMER NOTICE: LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. Unless noted: Resistors: Ohms 0402 1% 1/16W Capacitors: 0402 10% 10V 1 JP1 RUN JP1 - JP2 SETTINGS Q1 Si2319DS OPT 1 3 CMSH3-40MA 1 3 1 3 VIN 17.7V - 34V 1 3 D1 1 2 3 GND SYSTEM LOAD GND J1 (OPT) E7 NTC DF3-3P-2DSA BAT GND NTC E6 BAT 14.4V / 13.5V 2A E5 E4 E3 DEMO MANUAL DC1688A SCHEMATIC DIAGRAM dc1688afa 5 DEMO MANUAL DC1688A 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 dc1688afa 6 Linear Technology Corporation LT 0412 REV A • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 2010