Sampling short-circuit protection circuit for high-power factor driving system and method

The invention provides a sampling short-circuit protection circuit for a high-power factor driving system and a method. The high-power factor driving system can comprise a power conversion circuit, a power factor correction (PFC) control circuit, a switching tube and a sampling resistor coupled to the switching tube. The PFC control circuit can comprise a PFC control module which is used for generating a driving signal to control the on and off of the switching tube, and a sampling short-circuit protection circuit. The sampling short-circuit protection circuit can comprise a short-circuit detection circuit and a logic circuit, wherein the short-circuit detection circuit is used for determining that the sampling short circuit is detected after an input voltage signal provided by an input source of the power conversion circuit is greater than a first reference voltage and a sampling voltage signal detected by a sampling resistor is continuously less than a second reference voltage for a predetermined number of periods; the logic circuit is used for generating a protection signal when the short-circuit detection circuit detects the sampling short circuit till receiving an undervoltage signal which indicates that the PFC control circuit is in an undervoltage state; and the protection signal enables the PFC control module to shut down the switching tube.