MDI FAULT DETECTION APPARATUS USING INITIAL TURN-ON AND NOISE TIMERS

摘要

A motor driver interface (MDI) circuitincludes fault detection apparatus effective to detectshort circuits to the power supply in the switchingtransistors of an H-bridge reversible DC motorarrangement. A pair of timers distinguishes a truefault condition. The first timer is responsive to acontinuous fault detection to define a first timeperiod from its initiation; and a second timer isresponsive to a continuous presence of a transistorconduction signal to define a second time period fromits initiation. The apparatus stores a fault signal inresponse to the detection of the fault condition at theend of the first or second time periods with the firsttimer providing fault detection upon turn-on after thebrief initial high transistor turn-on current and thesecond timer providing noise immunity.