Circuit for eliminating signal offset of charge amplifier

Abstract

The invention discloses a circuit for eliminating the signal offset of a charge amplifier, and the circuit comprises: a front circuit module which is used for outputting a first voltage signal according to a first charge signal; a monitoring circuit module which is used for outputting a monitoring signal according to the first voltage signal; a control module which is used for outputting a first control signal when the monitoring signal meets a preset condition; a sampling hold circuit module which is used for outputting an offset signal according to the first control signal and the first voltage signal and keeping the size of the offset signal unchanged within a certain time, wherein the control module is also used for controlling the measuring equipment to carry out variable testing, and the front circuit module is also used for outputting a second voltage signal to the subtraction circuit module according to the second charge signal; and a subtraction circuit module which is used for outputting a variable signal according to the second voltage signal and the offset signal, wherein by adopting the circuit provided by the invention, the offset of the charge amplifier can be effectively eliminated.

Description

technical field [0001] The invention relates to the technical field of piezoelectric coefficient measurement, in particular to a circuit for eliminating the signal offset of a charge amplifier. Background technique [0002] The existing charge amplifier generally consists of a charge conversion circuit, an amplification circuit, a filter circuit, an overload indicator, a regulated power supply, and the like. [0003] This type of amplifier often requires the input signal to be a stable and regular signal, but because the charge input signal is easily affected by changes in electromagnetic waves, ambient temperature, humidity, etc., the input signal varies, which limits its use scenarios. For example, when the input signal has a certain offset to the ground, the amplifier will amplify the offset at the same time. When the offset is small, the output will not be affected; however, when the offset is large to a certain extent, the input signal After being amplified, it is over...

AI Technical Summary

Problems solved by technology

[0003] This type of amplifier often requires the input signal to be a stable and regular signal, but because the charge input signal is easily affected by changes in electromagnetic waves, ambient temperature, humidity, etc., the input signal changes indefinitely, which limits its use scenarios

For example, when the input signal has a certain offset to the ground, the amplifier will amplify the offset at the same time. When the offset is small, the output will not be affected; however, when the offset is large to a certain extent, the input signal After being amplified, it is overloaded and exceeds the range of the amplifier. At this time, the amplifier can no longer output the signal normally.

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