Patent ID: 7659777
Filing Date: 2010-02-09
Classification: H03F

Abstract:
1. An offset adjustment device, comprising an operational amplifier that includes at least a non-inverting input terminal and an inverting input terminal, the offset adjustment device causing a storage section to store a binary logical signal indicative of an output voltage of the operational amplifier at a time when an output of the operational amplifier is not fed back to the non-inverting input terminal and the inverting input terminal and when the non-inverting input terminal and the inverting input terminal are short-circuited with each other, the logical signal having (i) a first logical value in a case where the output voltage is positive with respect to a reference value that is an ideal output voltage of the operational amplifier when a differential input is 0, and (ii) a second logical value in a case where the output voltage is negative with respect to the reference value, the offset adjustment device adjusting an offset of the output voltage of the operational amplifier with respect to the reference value by using the logical signal stored in the storage section.