Dual-Input Battery Charger Integrates OVP

The AAT3691 dual input battery charger IC integrates over-voltage protection (OVP) up to 28V with a response time of less than 1 µs and supports inputs from both ac adapters and USB ports. The device intelligently assesses which input source offers minimum charging time and modifies the charge path while the OVP protects the battery and system against faulty inputs. It regulates battery-charge voltage and current for 4.2V lithium-ion cells and operates across a 3V to 6.75V input range. Charge current is programmable up to 1.6A for charging via an adapter and up to 0.5A for charging via a USB port using external resistors. When adapter or USB input power exceeds 6.75V typical, an internal series switch opens preventing damage to the battery or charging circuit. Charging and OVP total on resistance is 600 milliOhms maximum. Other features include a no-battery-present input detection function that prevents input power from passing through the OVP block and suspends charging when no battery is present or a battery trace or connector is defective. Available in a 16-pin, 3 mm x 4 mm TDFN package, price is $1.12 each/1,000. ANALOGIC TECHNOLOGIES INC., Sunnyvale, CA. (408) 737-4600.