Patent ID: 6222751
Filing Date: 2001-04-24
Classification: H02M,H03K

Abstract:
A driver circuit for a polyphase DC motor having an inductive load comprising:a power supply having first and second terminals;an output terminal;a half-bridge output stage including a pair of transistors having a common terminal connected to the output terminal for connection to the inductive load of the DC motor, and each having a power terminal connected to the first and second terminals, respectively, of the power supply;a pair of amplifiers connected to drive the pair of transistors in a push-pull operation;a pair of capacitors each operatively connected between the output terminal and a respective amplifier of the pair of amplifiers;a first pair of switches connected to inputs of the amplifiers;a second pair of switches connected to the inputs of the amplifiers;a first constant current generator selectively connected to either of the amplifiers via the first pair of switches;a second constant current generator selectively connected to either of the amplifiers via the second pair of switches;a commutation sequencer operatively connected to the first and second pairs of switches for turning the switches on and off according to a commutation program; anda detecting circuit connected to the output terminal for detecting predetermined voltage conditions at the output terminal and providing the commutation sequencer with signals for conditioning the commutation program as a function of detected voltage conditions.