Battery charger IC protects against faulty input voltages

The AAT3783 is a 1A linear Li-ion/Polymer battery charger IC with an integrated over-voltage protection (OVP) switch. Designed to charge 4.2V Li-ion /Polymer battery cells from either AC or USB inputs, the charger IC also features a digital thermal management system that maximises charging efficiency and shortens battery recharge time.

The AAT3783 integrates a charging device, a reverse blocking diode and current sensing circuitry in the same die. It operates off a 4.0V to 7.5V input range and supplies a programmable current from 100mA to 1A.

To maximise charging current under all operating conditions, the AAT3783 features a special digital thermal management system that measures the internal die temperature and reduces the fast charge current when the device exceeds a preset threshold. This thermal loop control constantly re-evaluates the circuit die temperature and adjusts the fast charge current up or down in small steps until an equilibrium current is reached. Since the thermal loop controls the system charge level, it maximises charging efficiency by ensuring the charger will use the highest level of constant current in fast charge mode possible for any given ambient temperature condition.

The AA3783 also features over-voltage, over-current, short-circuit and over-temperature circuits that automatically protect the charging device, control system and battery-under-charge by shutting down the system when a fault occurs. A status monitor output pin is provided which can be used to indicate battery charge status by directly driving an external LED.

Qualified across the -40 C to +85 C temperature range, the AAT3783 is available in a Pb-free, 16-pin TDFN package.