Two stage decoder circuit using threshold logic to decode high-order bits and diode-matrix logic to decode low-order bits

摘要

A two-stage decoder circuit includes a first-stage decoder circuit, for decoding upper bits of an input signal, and a second-stage decoder circuit, which is activated by receiving a selected output signal of the first-stage decoder circuit and which decodes lower bits of the input signal. The first-stage decoder circuit is formed by a threshold-operation type logic circuit which carries out selection or non-selection by comparing the input signal with a predetermined threshold level, and the second-stage decoder circuit is formed by a diode-matrix circuit.