Operation amplifier gain measurement circuit

Abstract

The invention discloses an operation amplifier gain measurement circuit, comprising an operation amplifier, a first analog-to-digital converter, a second analog-to-digital converter, a second analog-to-digital converter, a digital processing module, a switch and a four resistors (from the first resistor to the fourth resistor); terminals of the resistors from the first resistor to the third resistor and the input terminal of the first analog-to-digital converter are commonly connected to an X point; the other terminal of the second resistor, the output terminal of the operation amplifier, and the input terminal of the second analog-to-digital converter are commonly connected to an Y point; the other terminals of the third resistor and the fourth resistor and the inverted input terminal of the operation amplifier are commonly connected to a P point; the other terminal of the fourth resistor and the input terminal of the operation amplifier are commonly connected to first voltage; the other terminal of the first resistor is connected to second voltage or third voltage through the switch; and the output terminals of the first analog-to-digital converter and the second analog-to-digital converter are connected to the input terminals of the digital processing module. The invention can accurately measures the practical gain of the operation amplifier and regulates the gain. In the high gain operation amplifier with a negative resistance unit, the invention can control the negative resistance value according to the practical gain so as to guarantee to achieve the target gain value under the condition that the operation amplifier is stable.

Description

technical field [0001] The invention belongs to the field of operational amplifiers and relates to an operational amplifier gain measurement circuit. Background technique [0002] High-gain operational amplifiers have a wide range of requirements in feedback systems. Taking high-precision pipelined analog-to-digital converters as an example, high-gain operational amplifiers in the pipeline stage are an important condition to ensure conversion accuracy, so their performance must be accurately measured. High-gain op amps are difficult to measure accurately, however, since pickup, stray current, or thermocouple effects may produce very small voltages at the op amp input, and errors will be unavoidable. Contents of the invention [0003] The invention provides an operational amplifier gain measuring circuit, the purpose of which is to accurately measure the actual gain of the operational amplifier. [0004] Technical scheme of the present invention is as follows: [0005] An...

AI Technical Summary

Problems solved by technology

However, due to pickup, stray current, or thermocouple effects that may generate very small voltages at the input of the op amp, errors will be difficult to avoid, so high-gain op amps are difficult to measure accurately

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