Switching circuits employing surface potential controlled semiconductor devices

1,057,917. Transistor switching circuits. INTERNATIONAL BUSINESS MACHINES CORPORATION. May 4, 1964 [May 7, 1963], No. 37518/66. Divided out of 1,057,916. Heading H3T. In a logic or switching circuit utilizing a transistor having an additional surface-potentialcontrolling gate electrode 24, the input is fed to the gate and a diode 60 is provided between gate and base. The circuit may exhibit an exclusive-OR function so that in the absence of inputs to the summing circuit 62, diode 60 is conductive hence the transistor 20 is cut off on the base 26. Unlike inputs to A, B reverse-bias the diode so that the transistor 20 is turned on by current in resistor 42. Like inputs at A, B, however, raise the gate 24 voltage sufficiently to cut off the transistor 20 by field effect action.