Automatic elimination circuit for input offset voltage of operational amplifier

Abstract

The invention relates to an automatic elimination circuit for input offset voltage of an operational amplifier, which comprises a first control module, a second control module, a first current sourcemodule, a second current source module and an operational amplifier module, wherein the first control module generates a first control signal according to an output signal of the operational amplifiermodule; the second control module generates a second control signal according to the output signal of the operational amplifier module; the first current source module and the second current source module generate current signals according to the second control signal; the operational amplifier module achieves elimination of input offset voltage according to the current signal and achieves switching between an offset elimination mode and a working mode according to the first control signal. The automatic elimination circuit provided by the invention does not influence the working state of theoperational amplifier while eliminating the offset voltage.

Description

technical field [0001] The invention belongs to the technical field of integrated circuits, and in particular relates to an automatic elimination circuit of an operational amplifier input offset voltage. Background technique [0002] As the key circuit unit of analog integrated circuits, operational amplifiers are widely used in A / D (analog / digital) converters and D / A (digital / analog) converters to realize functions such as circuit driving and analog-to-digital conversion. In some application fields such as test and measurement, the static parameters of gain error and offset error of A / D or D / A converter are very important performance indicators. For example, the time domain interleaving analog-to-digital converter achieves the design goal of high sampling rate of the converter by sampling the input signal through each channel converter in turn in the time domain, but the mismatch between the gain error and offset error of each channel converter Harmonics will appear in the...

AI Technical Summary

Problems solved by technology

In the process of circuit design, it is usually taken to maximize the matching of transistors in the layout layout, or to optimize the size of transistors to minimize the input offset voltage of the operational amplifier, but in general, the input offset voltage of the amplifier is between cannot be adequately eliminated after taking the above measures

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