Low-offset input circuit including amplifier circuit to correct circuit characteristics to cancel offset of the input circuit

Abstract

In a signal transmission system where an influence of the circuit characteristic variation of an input circuit on signal receiving operation cannot be ignored, there is provided a method of realizing a low-offset input circuit which is capable of conducting high-speed operation and always continuing signal receiving operation without increasing the number of terminals of a semiconductor integrated circuit and without the necessity of providing additional signal observing means and variation adjustment amount calculating means to the external of the semiconductor integrated circuit. In a signal receiver circuit having an input circuit, an automatic zero amplifier, an analog/digital converter circuit, an encoder circuit, and a signal holding circuit, an output error signal of the input circuit is amplified by the automatic zero amplifier, and the signal is digitalized or the digitalized signal is encoded as the occasion demands, and held by the holding circuit, and the circuit characteristic variation of the input circuit is adjusted by the held signal.