Overcurrent Protection Circuit
Original Publication Date: 1988-Jan-01
Included in the Prior Art Database: 2005-Feb-14
This article describes an overcurrent protection circuit for protecting a power regulator and automatically restarting it when an error condition is removed. The circuit operates by putting the regulator into a low-duty cycle relaxation mode during an overload condition. The regulator is allowed to operate for a short time during the overload condition. It is then turned off for a much longer time. Normal operation resumes at the end of the off time. If the overload condition is still present, the regulator is turned off again and the cycle is repeated. Since the duty cycle is low, the average power delivered by the regulator is greatly reduced and protection is achieved. As is shown in the figure, overcurrent is detected with overcurrent (O/C) sense circuit 10.