Operational amplifier circuit offset voltage calibration method, device thereof and system

Abstract

The invention discloses an operational amplifier circuit offset voltage calibration method, a device thereof and system and a computer readable storage medium, a compensation circuit is composed of a current calibration circuit and a resistance calibration circuit, and after a to-be-compensated voltage is determined according to a difference value between an actual offset voltage and an allowable offset voltage of a to-be-compensated amplifier circuit, the magnitude and direction of unit compensation current of a variable current source in a current calibration circuit of the compensation circuit are determined according to the magnitude and polarity of the to-be-compensated voltage, the access resistance of a resistance calibration circuit of the compensation circuit is determined according to the unit compensation current and the to-be-compensated voltage, repairing is carried out from the two angles of the access resistance and the current flowing through the access resistance, compared with a traditional binary system current compensation scheme which only adopts divider resistors to carry out trimming, the calibration means is more flexible, the number of the needed divider resistors is obviously reduced, namely, the area of a compensation circuit is reduced under the same compensation precision, higher compensation precision can be obtained, so that the linearity of offset voltage calibration is improved.

Description

technical field [0001] The present application relates to the field of integrated circuit chip design, in particular to a method, device, system and computer-readable storage medium for calibrating the offset voltage of an operational amplifier circuit. Background technique [0002] In a signal chain processing circuit, the fixed-gain op amp / instrumentation amplifier in the first stage usually has a gain error in the final output stage due to the presence of offset voltage. The offset voltage of the first stage is generally caused by the mismatch of the operational amplifier itself or the mismatch of the resistor resistance / capacitance ratio of the feedback loop. Among them, the mismatch of the operational amplifier itself can be eliminated by Chopper technology or Correlated Double Sampling (CDS related double sampling) technology to the range required by the index, and the ratio mismatch of resistor resistance / capacitance is mainly caused by process deviation. The offset ...

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Problems solved by technology

Among them, the mismatch of the operational amplifier itself can be eliminated by Chopper technology or Correlated Double Sampling (CDS related double sampling) technology to the range required by the index, and the ratio mismatch of resistor resistance / capacitance is mainly caused by process deviation. The offset voltage cannot be eliminated by inherent technology, and the offset voltage can only be reduced by means of trimming.

[0003] The traditional method of trimming the ratio mismatch of the resistance value / capacitance value of the operational amplifier is a binary current compensation scheme, that is, the ratio mismatch of the resistance value / capacitance value is corrected by a compensation circuit composed of a voltage divider For trimming, in order to achieve the required compensation accuracy, a large number of voltage divider resistors are required, resulting in a large circuit area, and a compromise between compensation accuracy and area is required, and the compensation accuracy is limited

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