over voltage and over current protection ic 100 is optimized for the safety of a battery charging system in for example a hand held system that utilizes a lithium ion battery which must be operated in a safe region in order to ensure that the battery does not catch fire or explode the ic 100 protects three possible failure mechanisms in a charging system input over voltage the voltage input to the overall system battery over voltage and charge current over current when any of the above three failure mechanisms occur the ic 100 turns off an internal p channel mosfet 102 to remove power from the charging system together with a battery charger ic not shown and a protection module in a battery pack the charging system has triple level protection to limit the battery cell voltage in a safe region the input over voltage protection ovp threshold is set to 6 5v internally but may be adjusted to other values easily using a metal spin when the input voltage exceeds the programmed threshold the ic 100 turns off the pfet 102 in less than 1 u03bcs to prevent the high voltage input from damaging the electronics in a handheld system the ic 100 is designed to withstand up to 30v of input voltage the current in the pfet 102 is over current protected and the threshold is programmable with an external signal resistor up to 1 5 a the over current protection ocp has a built in delay to prevent false triggering the battery ovp is realized through a battery voltage monitoring pin vb 104 the battery ovp threshold is set at 4 4v and a.