Bias current source for biasing pair of differential CMOS transistors utilized by operational amplifier, has pair of N-type transistors whose gate is connected to one point and another gate is connected to another point

摘要

The source (100) has a series-type switched capacitor circuit, and a pair of N-type complementary metal oxide semiconductor (CMOS) transistors (110, 111) connected in parallel between a set of points (A, C, D) and ground. A pair of P-type CMOS transistors (112, 113) complementary to the former pair of transistors is connected between one of the points and a voltage source (VDD). A gate of the pair of N-type transistors is connected to the other point, and another gate of the pair of N-type transistors is connected to the latter point. The capacitor circuit includes capacitor and switching units.