Date: 21/08/2009

Linear's 2A solar power buck battery charger IC for battery chemistries

Linear has introduced the LT3652, 2A solar power directed monolithic buck battery charger IC for modern battery chemistries. When the LT3652 is connected to a solar panel, the input regulation loop maintains the panel at peak output power, which controls charge current to hold the input voltage at a programmed level.

According to Steve Pietkiewicz, Vice President and General Manager of Power Products, "The LT3652's simple but unique input voltage regulation loop circuitry delivers virtually the same charging efficiency as more complex and expensive Maximum Peak Power Tracking (MPPT) techniques."

Key features are,

Solar Power Supply Voltage Regulation Loop for Peak Tracking in Solar Applications
Input Voltage Range: 4.95V to 32V (40V Absolute Maximum Rated)
Programmable Charge Current up to 2A
Multi-Chemistry: Resistor Programmable Float Voltage Up to 14.4V Accommodates Li-Ion/Polymer, LiFePO4, SLA, NiMH / NiCd Chemistries
User-Selectable Termination: C/10 or Onboard Termination Timer
Draws <1uA from the Battery During Non-Charging Periods
1MHz Switching Frequency Enables Small External Components
0.5% Float Voltage Feedback Reference Accuracy
±5% Charge Current Accuracy
NTC Resistor Temperature Monitor
Bad Battery Detection with Auto-Reset
Low-Profile (0.75mm) 3mm x 3mm DFN-12 Package

Applications include solar powered systems, 12V to 24V automotive equipment and battery chargers.

Once charging is terminated, the LT3652 automatically enters a low current standby mode that reduces the input supply current to 85uA. In shutdown, the input bias current is reduced to 15uA. For autonomous charge control, an auto-recharge feature starts a new charging cycle if the battery voltage falls 2.5% below the programmed float voltage.

Operating temperature range: - 40 °C to + 125 °C

Package: Low-profile (0.75mm) 12-pin 3mm x 3mm DFN package.
Price: Starts at $3.05 and $3.36 for 1k pieces.
For more details visit www.linear.com.