Communicating faults by a power stage of a multi-phase switching converter

Abstract

A power stage of a multi-phase switching converter detects faults reliably, and contains a high-side switch and a low-side switch connected in series between a first power terminal and a ground terminal. A gate driver generates drive signals to the two switches based on a control signal received from a phase controller. A fault logic block, powered at a second power terminal, generates (binary) deviation signals indicating whether or not a corresponding fault exists by examining states internal to the power stage. Ringing can occur at the ground and power terminals when the control signal switches between logic levels. The fault logic block generates fault signals by sensing the deviation signals according to a delayed version of the control signal, with the delay having a magnitude greater than a settling time of the ringing. By thus delaying the sensing of the deviation signals, any interference by the ringing is avoided.