Patent ID: 7233131

Claim:
A circuit for implementing a multi-function pin on a PWM controller chip in a voltage converter to switch a pair of high side and low side switches connected with a phase node therebetween to produce an output current from a converter power, the circuit comprising: a sense resistor connected between the multi-function pin and phase node; an enable arrangement for detecting a first voltage on the multi-function pin when the voltage converter starts up to enable the PWM controller chip; a power sensing arrangement for turning on the high side switch for a period and detecting a second voltage on the multi-function pin during the period and a chip power to identify if the converter power and chip power are ready; and an over-current protection arrangement for detecting a third voltage on the multi-function pin when the low side switch turns on to produce an over-current signal when the output current is greater than a threshold; the enablement, power sensing, and over-current protection arrangements each having an input coupled to the multi-function pin.