Texas Instruments Incorporated
Bipolar junction transistor buffer

Abstract:

A buffer circuit includes a first PNP BJT having a first base, a first collector and a first emitter. A first diode has a first cathode and a first anode. The first cathode couples to the first PNP BJT. A second diode has a second cathode and a second anode. The second anode couple to first base, and the second cathode couples to the first emitter. A voltage level shifter circuit coupled to the first anode. The voltage level shifter has a voltage level shifter output. A pre-driver circuit has a pre-driver input coupled to the voltage level shifter output. A second transistor has a second base, a second collector and a second emitter. The second base couples to the output of the pre-driver output. The second collector couples to a negative supply voltage node. The second emitter couples to an output node of the buffer circuit.