Optimize the integrated overcurrent protection of gate driver ICs for current sense range extension

Abstract:
Gate driver ICs with integrated overcurrent protection are often based on a comparator monitoring a shunt voltage and referencing it to a relatively high sense threshold voltage. In high-current applications, this results in high-power dissipation in the shunt resistor, if the shunt value for sensing the overcurrent is adjusted to the reference voltage. Alternatively, the shunt value can be selected for a lower power dissipation, which would result in a high overcurrent limit. This paper introduces a new method for adapting the overcurrent sense capability of such gate drivers. The simple, but robust, solution enables the overcurrent detection function in high-current applications using low-resistive shunt values. Hence, it solves the inherent design trade-off of shunt resistors in high-current applications.