Overcurrent protection for a buck-boost switching regulator

摘要

A four switch voltage converter is regulated for buck mode and boost mode under constant frequency valley-peak current mode control. Protection circuits are responsive to output voltage and regulator current to prevent excessive current that otherwise might result from abnormally low output voltage. short circuit, or spurious switching abnormalities during low duty cycle operation. The regulator control circuit is responsive to the protection circuits to automatically connect a regulator inductor between a common potential and the output to limit current.