Patent attributes
A synchronous rectifying drive type semiconductor circuit wherein voltages between drains and sources of power switching elements are detected, temporarily held and compared with a reference voltage. First control signals are generated for turning on the power switching elements depending on comparison result and dead times for the power switching elements are minimized by ORing first control signals and second control signals inputted at input terminals. The first control signals cause the power switching elements to be in “on” state for a constant time until the second control signals as “on” control signals arrive at the input terminals, and then the first control signals as “on” control signals are terminated before the second control signals as “off” signals arrive at the input terminals, thereby swiftly turning off the power switching elements by the second control signals arriving at the input terminals.