Patent ID: 9093961
Filing Date: 2015-07-28
Classification: H03F

Abstract:
1. An operational amplifier having an inverting input terminal, a non-inverting input terminal, and an output terminal, the operational amplifier comprising: a first comparator having a non-inverting input terminal of the operational amplifier connected to a non-inverting input terminal thereof and an inverting input terminal of the operational amplifier connected to an inverting input terminal thereof that has an input offset voltage; a second comparator having an inverting input terminal of the operational amplifier connected to a non-inverting input terminal thereof and a non-inverting input terminal of the operational amplifier connected to an inverting input terminal thereof that has an input offset voltage; an amplifier having the non-inverting input terminal of the operational amplifier connected to a non-inverting input terminal thereof and the inverting input terminal of the operational amplifier connected to an inverting input terminal thereof; a logic circuit connected to an output terminal of the first comparator and an output terminal of the second comparator; a first resistor and a first switch which are provided between the non-inverting input terminal and a ground terminal of the operational amplifier and which are connected in series; and a second resistor and a second switch which are provided between the inverting input terminal and a supply terminal of the operational amplifier and which are connected in series, wherein the first switch and the second switch are controlled by an output signal of the logic circuit.