LT3652 Power Tracking 2A Battery Charger for Solar Power FEATURESDESCRIPTION n Input Supply Voltage Regulation Loop for Peak The LT®3652 is a complete monolithic step-down bat- Power Tracking in (MPPT) Solar Applications tery charger that operates over a 4.95V to 32V input n Wide Input Voltage Range: 4.95V to 32V (40V Abs Max) voltage range. The LT3652 provides a constant-current/ n Programmable Charge Rate Up to 2A constant-voltage charge characteristic, with maximum n User Selectable Termination: C/10 or On-Board charge current external y programmable up to 2A. The Termination Timer charger employs a 3.3V float voltage feedback reference, n Resistor Programmable Float Voltage Up to 14.4V so any desired battery float voltage up to 14.4V can be Accommodates Li-Ion/Polymer, LiFePO4, SLA programmed with a resistor divider. Chemistries The LT3652 employs an input voltage regulation loop, which n No VIN Blocking Diode Required for Battery reduces charge current if the input voltage falls below a Voltages ≤ 4.2V programmed level, set with a resistor divider. When the n 1MHz Fixed Frequency LT3652 is powered by a solar panel, the input regulation n 0.5% Float Voltage Reference Accuracy loop is used to maintain the panel at peak output power. n 5% Charge Current Accuracy n 2.5% C/10 Detection Accuracy The LT3652 can be configured to terminate charging n Binary-Coded Open-Collector Status Pins when charge current falls below 1/10 of the programmed n Thermally Enhanced 12-Lead 3mm maximum (C/10). Once charging is terminated, the LT3652 × 3mm DFN and MSE Packages enters a low-current (85µA) standby mode. An auto-re- charge feature starts a new charging cycle if the battery APPLICATIONS voltage falls 2.5% below the programmed float voltage. n Solar Powered Applications The LT3652 also contains a programmable safety timer, n Remote Monitoring Stations used to terminate charging after a desired time is reached. n LiFePO This al ows top-off charging at currents less than C/10. 4 (Lithium Phosphate) Applications n Portable Handheld Instruments L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and PowerPath is a trademark of Linear Technology Corporation. All other trademarks are the n 12V to 24V Automotive Systems property of their respective owners. TYPICAL APPLICATIONSolar Panel Input VoltageRegulation, Tracks Max PowerPoint to Greater Than 98%2A Solar Panel Power Manager With 7.2V LiFePO4 Batteryand 17V Peak Power Tracking 22 TA = 25°C CMSH1-40MA SOLAR PANEL INPUT 20 (<40V OC VOLTAGE) SYSTEM LOAD CMSH3-40MA 10µF 18 100% TO 98% PEAK POWER 530k CMSH3-40MA V SW IN LT3652 1µF V 10µH 16 IN_REG BOOST 0.05 100k SHDN 98% TO 95% PEAK POWER SENSE CHRG 14 BAT FAULT NTC 542k 10µF TIMER V 12 FB INPUT REGULATION VOLTAGE (V) 459k + 10k 10 B = 3380 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 CHARGER OUTPUT CURRENT (A) 2-CELL LiFePO4 (2 × 3.6V) BATTERY PACK 3652 TA01a 3652 TA01b 3652fe For more information www.linear.com/LT3652 1 Document Outline Description Typical Application Absolute Maximum Ratings Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Applications Information Package Description Typical Application Related Parts
