Patent Number: 8,497,791

Title: Operational amplifier

Abstract: A temperature dependence adjustable operational amplifier circuit which suppresses a change in a gain caused by a change in an input voltage is provided. In an operational amplifier including a first input terminal and an output terminal, an operational amplifier having an inverting input terminal and a non-inverting input terminal, an input resistance circuit, and a feedback resistance circuit, each of the input and feedback resistor circuits has a resistor and a trimming resistor, which are different in temperature coefficient from each other, connected in series with each other, and a source-drain path of a MOS transistor included in the trimming resistor circuit is disposed between resistance and an inverting input terminal, and a substrate potential thereof is set to a potential of the inverting input terminal of the operational amplifier.

Inventors: Okumura; Atsushi (Hamura, JP), Sahara; Ryusuke (Mitaka, JP), Kusunoki; Mitsugu (Kunitachi, JP)

Assignee: Hitachi, Ltd.

International Classification: H03M 1/10 (20060101)

Expiration Date: 2021-07-30 0:00:00