Differential amplifier common-mode rejection ratio and gain trimming circuit

Abstract

The present invention provides a common-mode rejection ratio and gain trimming circuit of differential amplifier, comprising: a first trimming unit and a second trimming unit coupled between an in-phase input voltage and a reference voltage, wherein the first trimming unit and the second trimming unit are coupled to a positive input terminal of the differential amplifier by means of tap switches; a third trimming unit and a fourth trimming unit coupled between tan inverting input voltage and an output terminal of the differential amplifier, wherein the third trimming unit and the fourth trimming unit are coupled to a negative input terminal of the differential amplifier by means of tap switches; wherein, the first trimming unit, the second trimming unit, the third trimming unit, and the fourth trimming unit comprise: a first trimming resistor string and a second trimming resistor string coupled in series; the first trimming resistor string is coupled in parallel with a first trimming auxiliary resistor string, and the second trimming resistor string is coupled in parallel with a second trimming auxiliary resistor string; wherein, the second trimming resistor string of the first trimming unit is coupled to the second trimming resistor string of the second trimming unit, and the second trimming resistor string of the third trimming unit is coupled to the second trimming resistor string of the fourth trimming unit.

Dependencies are inferred from the claim text.