High-speed analogue computing using MOS FET mode control switching

In applications requiring high-speed mode control switching, such as in certain iterative computing techniques, the use of electromechanical relays or diode bridge switches has inherent limitations. Electromechanical relays have limited speed of operation and cannot be made to provide synchronous switching. Diode bridge switches require elaborate drive circuitry and, in addition, require careful matching of components to minimize off-set voltages. The availability of the Fairchild type FI-100* metallic oxide silicon insulated gate field effect transistor (MOS FET) makes possible a simple mechanization of an analogue switch possessing the advantages of high speed performance and negligible off-set voltage. This type is an enhancement mode FET which