Circuits including combined field effect and bipolar transistors

Claim 1

In a BIGFET circuit of the type comprising a first IGFET device having source, gate and drain regions, a bipolar transistor having emitter, collector and base regions, means comprising a bias source connected to the bipolar transistor collector region for biasing the bipolar transistor, the first IGFET drain region being connected to the bipolar base region, means for applying an input digital signal to the first IGFET gate region, and means for deriving an output digital signal from the bipolar emitter region, the improvement comprising: a second IGFET device having a gate region connected, by way of a completely passive transmission line, to the gate of the first IGFET, a source region connected to the bipolar transistor collector region, and a drain region connected to the emitter of the bipolar transistor; and means for periodically changing the emitter load impedance of the bipolar transistor and for periodically altering the current path through the bipolar transistor comprising a third IGFET device having a source region connected to the drain region of the second IGFET device, a drain region connected to a reference potential, and a gate region connected to a periodic switching means.