The LTC4056 is a low cost, single-cell, constant-current/ constant-voltage Li-Ion battery charger controller with a programmable termination timer. When combined with a few external components, the LTC4056 forms a very small standalone charger for single cell lithium-ion batteries.

Charge current and charge time are set externally with a single resistor and capacitor, respectively. The LTC4056 charges to a final float voltage accurate to ±0.6%. Manual shutdown is accomplished by grounding the TIMER/ SHDN pin, while removing input power automatically puts the LTC4056 into a sleep mode. Both the shutdown and sleep modes drain near zero current from the battery; the shutdown mode reduces supply current to 40µA.

The output driver is both current limited and thermally protected to prevent operating outside of safe limits. No external blocking diode or sense resistor is required. The LTC4056 also includes low battery charge conditioning (trickle charging), undervoltage charge current limiting, automatic recharge and a charge status output.

The LTC4056 is available in a low profile (1mm) 8-lead SOT-23 (ThinSOT^™) package.

Applications

• Cellular Telephones
• Handheld Computers
• Digital Cameras
• Charging Docks and Cradles
• Low Cost and Small Size Chargers