Power Tracking 2A Battery Charger for Solar Power

The LT3652 is a complete monolithic step-down battery charger that operates over a 4.95V to 32V input voltage range. The LT3652 provides a constant-current/constant-voltage charge characteristic, with maximum charge current externally programmable up to 2A. The charger employs a 3.3V float voltage feedback reference, so any desired battery float voltage up to 14.4V can be programmed with a resistor divider.

The LT3652 employs an input voltage regulation loop, which reduces charge current if the input voltage falls below a programmed level, set with a resistor divider. When the LT3652 is powered by a solar panel, the input regulation loop is used to maintain the panel at peak output power.

The LT3652 can be configured to terminate charging when charge current falls below 1/10 of the programmed maximum (C/10). Once charging is terminated, the LT3652 enters a low-current (85μA) standby mode. An auto-recharge feature starts a new charging cycle if the battery voltage falls 2.5% below the programmed float voltage. The LT3652 also contains a programmable safety timer, used to terminate charging after a desired time is reached. This allows top-off charging at currents less than C/10.

VIN Max

VFLOAT Max

Features

LT3652

32V

14.4V

Internal Reverse Blocking VBAT < 4.2V

LT3652HV

34V

18V

APPLICATIONS

* Solar Powered Applications

* Remote Monitoring Stations

* LiFePO4 (Lithium Phosphate) Applications

* Portable Handheld Instruments

* 12V to 24V Automotive Systems

* Input Supply Voltage Regulation Loop for Peak Power Tracking in (MPPT) Solar Applications

* Wide Input Voltage Range: 4.95V to 32V (40V Abs Max)

* Programmable Charge Rate Up to 2A

* User Selectable Termination: C/10 or On-Board Termination Timer

* Resistor Programmable Float Voltage Up to 14.4V Accommodates Li-Ion/Polymer, LiFePO4, SLA Chemistries