OVP Switch Protects Consumer Portables

Combining a low on resistance and fast response time, the AAT4684 over-voltage protection (OVP) chip protects mobile consumer electronics against voltage spikes up to 28V while offering an on resistance of 100 milliOhms typical at 4.5V. The device relies on a P-channel MOSFET power switch to break the connection between the power adapter and the battery charger when input voltage exceeds a preset level. It works with either an internally-programmable over-voltage trip point or an adjustable protection threshold programmed via two external resistors. Response time is 1 µs maximum. Other features include an under-voltage-lockout protection circuit that places the device into sleep mode and a typical quiescent current of 30 µA. With an operating temperature range from -40°C to +85°C, the AAT4684 is available in a lead-free, 12-pin TSOPJW package. ANALOGIC TECHNOLOGIES INC., Sunnyvale, CA. (408) 737-4600.