Level shift circuit

Abstract

Level shift circuit includes an operational amplifier, and an input resistor having one end connected to an output terminal of an amplifier circuit and the other end connected to the inverted input terminal of the operational amplifier. The level shift circuit further includes a level-shifting resistor of a resistance value RO having one end connected to the inverted input terminal of the operational amplifier and the other end connected to a ground, and a feedback resistor of a resistance value R1. Reference voltage Vref is applied to the noninverted input terminal of the operational amplifier. Output signal of the level shift circuit represents the output of the amplifier circuit having been shifted in level by a predetermined amount. If the amplitude center level of the output signal from the level shift circuit is represented by Vc, the level shift amount ΔV can be expressed as ΔV=Vc−Vref=(R1/R0)Vref With such arrangements, the level shift circuit can operate appropriately using only one reference voltage, without requiring any external capacitor.

Dependencies are inferred from the claim text.