Linear Technology Corporation introduces the LTC4065L, a tiny fully integrated standalone linear battery charger that charges single coin cell Li-Ion batteries up to 250mA without overheating the device or surrounding components. This full-featured IC offers a 4.2V ±0.5% accurate float voltage, 5% charge current accuracy, timer termination and C/10 detection and is housed in a miniature 2mm x 2mm DFN package. A complete solution requires only two discrete components (input capacitor and a charge current program resistor) and fits into a 2.5mm x 2.7mm x 0.75mm form factor. Its small size and ability to regulate low charge currents make it well suited for applications in small capacity rechargeable Lithium battery-powered portable devices such as MP3 players, wireless headsets and Bluetooth-enabled devices.

The LTC4065L requires no external MOSFET, sense resistor or blocking diode. A patented thermal regulation scheme prevents the junction temperature of the IC from exceeding 115C by reducing charge current during high power or high ambient temperature operation. Other features of the LTC4065L include a charge current monitor output for charge termination, recharge, trickle charging and charge status indication. Charge current is adjustable with a standard off-the-shelf resistor. The device is designed to work with supplies up to 5.5V, including those within USB specifications and from 5V wall adapters. During shutdown, the supply current is only 20uA and battery drain current is less than 1uA, extending battery run time.

The LTC4065L is rated for operation from -40°C to 85°C. Pricing starts at $1.10 each in 1,000-piece quantities.. 
 
Summary of Features: LTC4065L
 Standalone Charger: Termination, Pre-Charge, Charge Control and Recharge 
 Programmable Charge Current up to 250mA with ± 5% Accuracy 
 Safety Timer Charge Termination 
 C/10 Charge Current Detection Output
 
 Thermal Regulation Maximizes Charge Rate without Risk of Overheating
 Charge Status Indicator
 
 Charge Current Monitor Output for Charge Termination
 No External MOSFET, Sense Resistor or Blocking Diode Required
 Tiny Low-Profile (0.75mm) 2mm x 2mm DFN-6 Package