A high speed BiCMOS tristate buffer circuit

This paper presents a novel high speed BiCMOS tristate buffer for driving a large capacitive load by using the pass transistor technique to achieve a single MOS driving bipolar transistor. With a single MOS driving, it can increase the driving capability as well as reduce the number of large MOS transistors that are required to drive a bipolar compared with previous designs. In addition, the feedback circuit to achieve a full-swing operation from supply voltage to ground is added. The simulation results for the switching characteristics, rise time, fall time and base current during enable as well as the voltage waveform during disable have been presented.