In the current Miller circuit which is formed to the current Miller circuit and

摘要

When a current mirror circuit is composed of transistors that inevitably form a parasitic photodiode between an epitaxial layer and a substrate layer because of structure of an integrated circuit, a photocurrent increases in proportional to an area of the epitaxial layer. Thus, the area of the epitaxial layer is adjusted in accordance with a current ratio of the current mirror, so as to allow the photocurrent to affect equally on both input and output sides of the current mirror circuit, i.e., so as to cancel the photocurrent. With this, in a current mirror circuit provided in an integrated circuit, it is possible to eliminate the influence of the photocurrent, without considerably increasing an element area or taking special measures to shield light.