AnalogicTech Announces 1A Linear Li-ion/Polymer Battery Charger IC With Integrated OVP Switch
Advanced Analogic Technologies Inc. (AnalogicTech) announced the AAT3783, 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 new charger IC also features a digital thermal management system that maximizes charging efficiency and shortens battery recharge time.
"Today many manufacturers of cellular handsets, Bluetooth headsets, MP3 players and other portable systems require over-voltage protection to protect the battery and system against faulty inputs," noted Siamak Bastami, Product Line Director at AnalogicTech. "By integrating an isolated OVP switch, the AAT3783 Li-Ion/Polymer battery charger offers protection against single point failures up to 28V while reducing component count and simplifying design."
The AAT3783 integrates a charging device, a reverse blocking diode and current sensing circuitry in the same die. It operates off a 4.0 to 7.5V input range and supplies a programmable current from 100mA to 1A.
To maximize 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 maximizes 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 which 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 to +85°C temperature range, the AAT3783 is available in a Pb-free, 16-pin TDFN package. The device sells for $0.95 in 1K quantities.
