Design of over-current protection circuit for power transistors

The paper presents an over-current protection circuit designed for high voltage power switches. The proposed protection mechanism employs a current limiter to monitor the current flowing through the power switch. The current limiter protects the power switch from potential damage by automatically switching off the device once the current exceeds the preset rating value. Simulated results exhibit that the capability of the designed current limiter can work up to 1 MHz where the maximum current is above 1A using 0.25 μm Bipolar-CMOS-DMOS (BCD) technology.