NPN transient driver circuit

摘要

A transient driver circuit for use with a logic circuit having an emitter-follower output stage that sources current to a load connected to an output thereof in response to an applied logic signal being at a first logic level. The transient driver circuit includes a first NPN transistor the collector-emitter path of which is coupled between the output of the logic circuit and the negative power supply rail, a second NPN transistor having its collector-emitter path couple between a positive power supply rail and the collector of the first NPN transistor and its base adapted to receive the logic signal and feedback circuitry that is responsive to a rise in the collector voltage of the second NPN transistor occurring as the logic signal switches to a second logic level for supplying current drive to the base of the first NPN transistor thereby turning it on to sink a large transient current at the output of the logic circuit.