Multi level coding and decoding system - uses MOS transistors having their grids controlled by binary digit bits and source connected to common output

摘要

The encoder and decoder consists of an MOS transistor for each bit with its gate driven by a bit and their sources commoned to produce a current output. The analogue to digital current converter consists of a multi drain transistor to equally distribute the input current to decoders for each bit with predetermined weights. Each level decoder corresponding to a binary bit receives a weight input from each parallel stage corresponding to a more significant bit. Weighting is achieved by adjusting the current gains of the MOS transistors. By incorporating the coders and decoders within integrated circuits to replace bus interconnecting the number of required pins is reduced.