Patent ID: 7593200

Claim:
A circuit for detecting faults in a converter, the converter including a switching stage having high- and low-side series switches connected together at a switching node and fault circuitry for managing a plurality of fault conditions, an input voltage source at an input rail being provided at one terminal of the high-side switch, the circuit comprising: a gate driver circuit connected to gate terminals of the high- and low-side switches for providing PWM signals to control the switching stage; a comparator circuit for comparing a voltage at the switching node to an input voltage from the input voltage source and providing an output signal, the comparator circuit having an output terminal, and positive and negative input terminals; a capacitor connected in series with the output terminal of the comparator circuit to generate an AC component of the comparator circuit output signal; and a rectifier circuit connected in series with the capacitor for rectifying the AC component of the comparator circuit output signal and providing a fault-indicating signal to the gate driver circuit, wherein the fault-indicating signal is used to drive the fault circuitry to detect a fault condition selected from a plurality of fault conditions in the converter, wherein the plurality of fault conditions is selected from at least one of input rail floating, high-side switch gate floating, high-side switch shorted and high-side switch open.