Over-Voltage Protection Controllers Include Battery-Switchover Function

Designed to protect low-voltage systems up to 28 V, the MAX4959 and MAX4960 over-voltage protection (OVP) controllers include battery-switchover capability. The devices provide resistor-programmable over-voltage (6 to 28 V) and under-voltage (5 to 28 V) trip levels. To implement the OVP, the MAX4959/MAX4960 turn off an external pFET when the input voltage exceeds the over-voltage threshold. Subsequently, they hold the external pFET off until the input voltage rises above the under-voltage-lockout (UVLO) threshold. The controllers also feature a control-bit pin that switches to the battery when the host system detects a disconnect at the ac adapter. This combination of OVP and battery-switchover functionality makes the MAX4959/MAX4960 well-suited for low-voltage systems such as ultra-mobile PCs, notebooks, and camcorders. The devices provide ±15-kV ESD protection (Human Body Model) on the input when the input is bypassed with an external 1 µF ceramic capacitor. The MAX4959/MAX4960 are fully specified over the –40°C to 85°C extended temperature range, and come in 2- by 2-mm, 10-pin microDFN and 3 by 5-mm, 10-pin microMAX packages. Prices start at $0.90 for quantities of 1000. MAXIM INTEGRATED PRODUCTS, Sunnyvale, CA. (408) 737-7600.