LTC4064

The LTC4064 is a standalone linear charger optimized for prolonging the life of 1-cell Li-ion batteries in battery backup applications. By charging to a float voltage of 4V instead of 4.2V or 4.1V, the LTC4064 decelerates the aging process and capacity degradation when the battery is unused for long periods of time but must be in a ready state.

An external capacitor programs a safety timer to terminate the charge cycle while the charge current is set externally with a single resistor. When the input supply is removed, the LTC4064 automatically enters a low current sleep mode, dropping the battery drain current to less than 3mA.

Additional safety features designed to maximize battery lifetime and reliability include NTC temperature sensing and low battery charge conditioning (trickle charging).

The IC contains an on-chip power MOSFET and eliminates the need for an external sense resistor and blocking diode. The LTC4064 also includes C/10 detection circuitry, AC present logic, and fault detection circuitry.