CN113489466A - Circuit for eliminating signal offset of charge amplifier - Google Patents
Circuit for eliminating signal offset of charge amplifier Download PDFInfo
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- CN113489466A CN113489466A CN202110799565.0A CN202110799565A CN113489466A CN 113489466 A CN113489466 A CN 113489466A CN 202110799565 A CN202110799565 A CN 202110799565A CN 113489466 A CN113489466 A CN 113489466A
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- 238000012360 testing method Methods 0.000 claims abstract description 43
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
- H03F3/70—Charge amplifiers
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R1/00—Details of instruments or arrangements of the types included in groups G01R5/00 - G01R13/00 and G01R31/00
- G01R1/30—Structural combination of electric measuring instruments with basic electronic circuits, e.g. with amplifier
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R29/00—Arrangements for measuring or indicating electric quantities not covered by groups G01R19/00 - G01R27/00
- G01R29/22—Measuring piezoelectric properties
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Abstract
The invention discloses a circuit for eliminating signal offset of a charge amplifier, which comprises a front circuit module, a first voltage signal and a second voltage signal, wherein the front circuit module is used for outputting a first voltage signal according to a first charge signal; the monitoring circuit module is used for outputting a monitoring signal according to the first voltage signal; the control module is used for outputting a first control signal when the monitoring signal meets a preset condition; the sampling and holding circuit module is used for outputting an offset signal according to the first control signal and the first voltage signal and keeping the magnitude of the offset signal unchanged within a certain time; the control module is also used for controlling the measuring equipment to carry out variable testing; 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 the subtraction circuit module is used for outputting a variable signal according to the second voltage signal and the offset signal, and the offset of the charge amplifier can be effectively eliminated by adopting the circuit of the invention.
Description
Technical Field
The invention relates to the technical field of piezoelectric coefficient measurement, in particular to a circuit for eliminating signal offset of a charge amplifier.
Background
The existing charge amplifier generally comprises a charge conversion circuit, an amplifying circuit, a filter circuit, an overload indicator, a voltage-stabilized power supply and the like.
Such amplifiers often require that the input signal is a stable and regular signal, but the charge input signal is easily affected by changes of electromagnetic waves, ambient temperature, humidity and the like, so that the change of the input signal is indefinite, and the use scene of the amplifier is limited. For example, when the input signal has a certain offset to the ground, the amplifier will amplify the offset at the same time, and when the offset is small, the output will not be affected; however, when the offset is large to a certain extent, the input signal is overloaded after being amplified and exceeds the range of the amplifier, and at this time, the amplifier cannot normally measure and output the signal.
Disclosure of Invention
The invention aims to provide a circuit for eliminating the offset of a charge amplifier, which can effectively eliminate the signal offset of the charge amplifier and ensure that the amplifier can normally measure and output signals.
In order to achieve the purpose, the technical scheme of the invention is as follows:
a circuit for canceling charge amplifier signal offset, comprising:
the monitoring circuit module is electrically connected with the front circuit module; the control module is electrically connected with the monitoring circuit module; the sampling and holding circuit module is electrically connected with the control module; the subtraction circuit module is electrically connected with the sampling and holding circuit module; the sampling hold circuit module and the subtraction circuit module are also electrically connected with the front circuit module;
the front circuit module is used for outputting a first voltage signal according to a first charge signal, and the first charge signal is generated before variable testing;
the monitoring circuit module is used for outputting a monitoring signal to the control module according to the first voltage signal;
the control module is used for outputting a first control signal to the sample-and-hold circuit module when the monitoring signal meets a preset condition;
the sampling and holding circuit module is used for outputting an offset signal to the subtraction circuit module according to the first control signal and the first voltage signal, and keeping the magnitude of the offset signal unchanged within a certain time;
the control module is also used for controlling the measuring equipment electrically connected with the monitoring signal to carry out variable test when the monitoring signal meets the preset condition;
the front circuit module is further configured to output a second voltage signal to the subtraction circuit module according to a second charge signal, where the second charge signal is generated in a variable test process;
and the subtraction circuit module is used for outputting a variable signal according to the second voltage signal and the offset signal.
Preferably, the circuit further comprises: and the level lifting circuit module is electrically connected with the subtraction circuit module and the control module and is used for lifting the level of the variable signal and outputting the level to the control module.
Preferably, the control module is further configured to output a second control signal to the sample-and-hold circuit module when the monitoring signal meets a non-preset condition;
and the sampling and holding circuit module is used for entering a sampling state according to the second control signal and outputting an offset signal according to the second control signal and the first voltage signal.
Preferably, the control module is further configured to control the measurement device not to perform a variable test when the monitoring signal does not meet a preset condition;
and the subtraction circuit module is used for outputting a variable signal according to the first voltage signal and the offset signal, wherein the variable signal is zero at the moment.
Preferably, the monitoring circuit module includes a voltage dividing circuit;
the monitoring signal is an intermediate voltage division value of the voltage division circuit,
the preset condition is that the intermediate partial pressure value is within a preset range;
the control module is configured to output the first control signal when the obtained intermediate voltage division value is within a preset range: and when the obtained intermediate partial pressure value is within a preset range, controlling the measuring equipment to carry out variable testing.
Preferably, the monitoring circuit module comprises a voltage dividing circuit which comprises a first end, a second end and two resistors connected between the first end and the second end;
the first end inputs a preset fixed voltage;
the second end is connected with the front circuit module to access the first voltage signal;
and a third end is connected between the two resistors, and the monitoring signal is output to the control module through the third end.
Preferably, the sample-and-hold circuit module includes:
the input end of the sample-hold amplifier is connected with the first voltage signal, and the output end of the sample-hold amplifier is connected with the subtraction circuit module:
and the base electrode of the triode is connected with the first control signal, the collector electrode is connected with a positive voltage, the emitter electrode is grounded, and the collector electrode is also connected with the logic end of the sample-hold amplifier.
The first control signal is at a high level;
when a high level is input, the triode of the sample-and-hold circuit module is conducted, at the moment, the sample-and-hold amplifier is in a hold state, and the offset signal output by the output end of the sample-and-hold amplifier is the same as the first voltage signal in the conduction moment of the triode.
Preferably, the second control signal is at a low level;
when the control signal is at a low level, the triode of the sample-and-hold circuit module is turned off, at the moment, the sample-and-hold amplifier is in a sampling state, and the offset signal output by the output end of the sample-and-hold amplifier is the same as the first voltage signal in size and changes along with the first voltage signal in size.
Preferably, the subtraction circuit module includes:
an operational amplifier;
the non-inverting input end of the operational amplifier is connected with a first branch and a second branch which are connected in parallel:
the reverse input end of the operational amplifier is connected with a third branch and a fourth branch;
the first branch is connected with a first resistor in series and used for accessing a first voltage signal or a second voltage signal;
a second resistor is connected in series on the second branch circuit and is used for grounding;
a third resistor is connected in series on the third branch and used for accessing an offset signal output by the sample-and-hold circuit module;
and a fourth resistor is connected in series on the fourth branch, and the other end of the fourth branch is connected with the output end of the operational amplifier.
For a better understanding and practice, the invention is described in detail below with reference to the accompanying drawings.
Drawings
FIG. 1 is a block diagram of a circuit for canceling charge amplifier signal offset according to an embodiment of the present application;
FIG. 2 is a schematic circuit diagram of a front-end circuit module according to an embodiment of the present application;
FIG. 3 is a schematic circuit diagram of a monitoring circuit module according to an embodiment of the present application;
FIG. 4 is a schematic diagram of a circuit structure of an embodiment of the present application using a holding circuit module;
fig. 5 is a schematic circuit diagram of a subtraction circuit module according to an embodiment of the present application.
Detailed Description
In order to better illustrate the invention, the invention is described in further detail below with reference to the accompanying drawings.
It should be understood that the embodiments described are only some embodiments of the present application, and not all embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present application without any creative effort belong to the protection scope of the embodiments in the present application.
The terminology used in the embodiments of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the embodiments of the present application. As used in the examples of this application and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.
When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the application, as detailed in the appended claims. In the description of the present application, it is to be understood that the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not necessarily used to describe a particular order or sequence, nor are they to be construed as indicating or implying relative importance. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.
Further, in the description of the present application, "a plurality" means two or more unless otherwise specified. "and/or" describes the association relationship of the associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship.
The circuit of the embodiment of the application is suitable for measuring the piezoelectric coefficient of the piezoelectric material and is also suitable for measuring infrared signals and the like by utilizing the pyroelectric characteristics of the material.
The measuring equipment electrically connected with the control module of the embodiment of the application can be piezoelectric coefficient measuring equipment, infrared emissivity measuring equipment and the like.
Correspondingly, the material is subjected to variable testing in the embodiment of the application, so that the charge quantity of the material is changed, a voltage signal is formed after the charge quantity of the material passes through the front circuit module, and a variable signal is further obtained through the circuit of the application.
The variable test can be a stress test, a temperature test, a stress test, a deformation test and the like.
The variable signal is the voltage signal variation caused by the charge variation of the material before and after the material is subjected to corresponding variable test.
For example: and when the piezoelectric coefficient of the piezoelectric material is measured by the piezoelectric coefficient measuring equipment, stress application test is carried out, and the variable signal is a stress application signal. Specifically, when a stress application test is performed on a piezoelectric material, the charge of the piezoelectric material changes, the change of the charge is amplified to form a voltage signal, and the stress application signal is further obtained through the circuit of the embodiment of the application. Namely the voltage signal variation before and after the stress application test. Similarly, if a temperature test is performed, the variable signal is a change in charge due to a change in temperature, and thus a change in voltage. Of course, the change in charge can be induced by testing the piezoelectric material for pressure, strain, stress, temperature, etc.
Preferably, the circuit is suitable for high temperature piezoelectric measurements on piezoelectric ceramics.
The circuit of the embodiment of the present application is described below by taking an example in which a piezoelectric material is subjected to a stress test by a piezoelectric coefficient measuring device and a piezoelectric coefficient is measured.
Fig. 1 shows a circuit 1 for canceling a signal offset of a charge amplifier according to an embodiment of the present application. The circuit includes:
a monitoring circuit module 200 electrically connected to the front circuit module 100; a control module 300 electrically connected to the monitoring circuit module; a sample-and-hold circuit module 400 electrically connected to the control module; a subtraction circuit module 500 electrically connected to the sample-and-hold circuit module; the sampling hold circuit module and the subtraction circuit module are also electrically connected with the front circuit module.
When the piezoelectric coefficient is measured, the front circuit module 100 can amplify a charge signal generated when the piezoelectric coefficient is measured and output a voltage signal to the rear circuit.
Specifically, if there is a ground offset signal, the front circuit module 100 can amplify and output the ground offset signal to a rear circuit. Specifically, in the embodiment of the present application, before the force application test is performed, the ground offset signal is defined as the first charge signal, that is, the first charge signal is measured by performing a piezoelectric coefficient measurement and is generated before the force application test. The first charge signal is 0 if there is no offset to ground signal.
When a force test is performed on the piezoelectric material in the presence of a ground offset signal, the front circuit module 100 can amplify and output a charge signal generated at this time to a rear circuit. The charge signal generated at this time is defined as a second charge signal, that is, the second charge signal is generated during the stress application test and is used for piezoelectric coefficient measurement. The second charge signal includes the force signal and the offset to ground signal generated by the force test, i.e., the second charge signal includes the first charge signal and the force signal.
It should be noted that, in the embodiment of the present application, the second charge signal is generated by performing a stress application test when performing piezoelectric coefficient measurement, and does not represent a limitation on the manner of generating the second charge signal. In other words, the second charge signal may also be generated when the piezoelectric material is subjected to a pressure, deformation, stress, temperature, or other change test.
The front circuit module is used for outputting a first voltage signal according to a first charge signal;
the monitoring circuit module is used for outputting a monitoring signal to the control module according to the first voltage signal;
the control module is used for outputting a first control signal to the sample-and-hold circuit module when the monitoring signal meets a preset condition;
the sampling and holding circuit module is used for outputting an offset signal to the subtraction circuit module according to the first control signal and the first voltage signal, and keeping the magnitude of the offset signal unchanged within a certain time;
the control module is also used for controlling piezoelectric coefficient measuring equipment electrically connected with the monitoring signal to perform stress application test when the monitoring signal meets a preset condition;
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 the subtraction circuit module is used for outputting a force application signal according to the second voltage signal and the offset signal.
The circuit of the application amplifies a generated first charge signal through a front circuit module and outputs a first voltage signal; the monitoring circuit module outputs a first control signal according to the first voltage signal; the sampling and holding circuit module outputs an offset signal according to the first control signal and the first voltage signal and keeps the offset signal unchanged for a certain time; meanwhile, the control module controls the piezoelectric coefficient measuring equipment to perform stress application test, and the front circuit module amplifies the generated second charge signal and outputs a second voltage signal; the subtraction circuit outputs a force application signal according to the second voltage signal and the offset signal, and the offset signal is effectively eliminated.
The control module is further used for outputting a second control signal to the sample-and-hold circuit module when the monitoring signal meets the condition which is not preset;
and the sampling and holding circuit module is used for entering a sampling state according to the second control signal and outputting an offset signal according to the second control signal and the first voltage signal.
The control module is also used for controlling the piezoelectric coefficient measuring equipment not to perform stress application test when the monitoring signal does not accord with the preset condition;
and the subtraction circuit module is used for outputting a force application signal according to the first voltage signal and the offset signal, and the force application signal is zero at the moment.
Specifically, when the monitoring signal meets the condition that the monitoring signal is not preset, the piezoelectric coefficient measuring device does not perform the stress application test, and therefore, the stress application signal is zero. The first voltage signal generated by the ground offset signal is cancelled in the subtraction circuit module. Specifically, the first voltage signal is divided into two paths, and one path of the first voltage signal passes through the monitoring circuit module, the control module and the sample-and-hold circuit module and then is output to the subtraction circuit module; and the other path of signal is directly input into the subtraction circuit module from the front circuit module, and the two paths of signals are mutually offset to obtain a zero stress application signal.
Wherein the front circuit module 100 includes: an amplifying circuit unit for converting the first charge signal into a first voltage signal and amplifying; the amplifying circuit unit is also used for converting the second charge signal into a second voltage signal and amplifying the second voltage signal.
Preferably, the amplifying circuit unit includes: a pre-stage charge amplifying unit 110 for converting the charge signal into a voltage signal; and a post-stage voltage amplifying unit 120 for amplifying the voltage signal and outputting the amplified voltage signal to the filter circuit unit.
Preferably, the front circuit module further includes: and a filter circuit unit 130 electrically connected to the amplifying circuit unit, for performing a filtering process on the amplified first voltage signal or the amplified second voltage signal.
The filter circuit unit comprises a low-pass filter unit and a notch filter unit. Specifically, the filter circuit unit can filter 50HZ notch and 100HZ low-pass filter, and effectively filter out high-frequency interference and power frequency interference in the first voltage signal or the second voltage signal.
The monitoring circuit 200 module includes a voltage divider circuit, the monitoring signal is an intermediate voltage-dividing value of the voltage divider circuit, and the preset condition is that the intermediate voltage-dividing value is within a preset range.
Specifically, the control module 300 is configured to output the first control signal when the obtained intermediate voltage division value is within a preset range: and when the obtained intermediate partial pressure value is within a preset range, controlling the piezoelectric coefficient measuring equipment to perform stress application test.
The control module 300 is configured to output the second control signal when the obtained intermediate voltage division value is not within a preset range: and when the obtained intermediate partial pressure value is not in the preset range, controlling the piezoelectric coefficient measuring equipment not to perform stress application test.
The monitoring circuit module 200 includes: the voltage division circuit comprises a first end, a second end and two resistors connected between the first end and the second end; the first end inputs a preset fixed voltage; the second end is connected with the front circuit module to access the first voltage signal; and a third end is connected between the two resistors, and the monitoring signal is output to the control module through the third end.
As shown, the monitoring circuit module 200 includes: the first end of the voltage divider 210 is connected to a voltage regulator circuit, which inputs a preset fixed voltage of 3.2V and includes a voltage regulator. Preferably, the voltage regulator is TL 431. The second end is connected with the front circuit module, specifically, connected with the filter circuit unit, so as to access the first voltage signal. The third terminal is arranged between the resistors R1 and R2 and outputs a control signal, namely an intermediate voltage division value, to the control module.
Taking the preset range of the intermediate voltage division value as 0-1.6V as an example, the control module outputs a first control signal when the intermediate voltage division value is within the range of 0-1.6V; and if the intermediate voltage division value is not within the range of 0-1.6V, the control module outputs a second control signal. Preferably, the first control signal is a high level signal, and the second control signal is a low level signal.
Preferably, the control module 300 is a single chip microcomputer.
Wherein the sample-and-hold circuit module 400 comprises:
the input end of the sample-hold amplifier is connected with the first voltage signal, and the output end of the sample-hold amplifier is connected with the subtraction circuit module:
and the base electrode of the triode is connected with the first control signal, the collector electrode is connected with a positive voltage, the emitter electrode is grounded, and the collector electrode is also connected with the logic end of the sample-hold amplifier.
As shown IN fig. 4, the input terminal IN of the sample-and-hold amplifier 410 is connected to the first voltage signal, and the output terminal OUT is connected to the subtraction circuit block; preferably, the sample-and-hold amplifier 410 is LF398, formed using NOPB packaging.
A base electrode B of the NPN type triode Q1 is connected to the first control signal; a collector C is connected with a positive voltage of +5V, and the collector is also connected with a LOGIC end LOGIC of the sample-hold amplifier; the emitter E is grounded.
Specifically, the first control signal is at a high level;
when a high level is input, the triode is conducted, at the moment, the sampling holding amplifier is in a holding state, and the offset signal output by the output end of the sampling holding amplifier is the same as the first voltage signal in the conduction moment of the triode.
The second control signal is at a low level;
when the control signal is at a low level, the triode of the sample-and-hold circuit module is turned off, at the moment, the sample-and-hold amplifier is in a sampling state, and the offset signal output by the output end of the sample-and-hold amplifier is the same as the first voltage signal in size and changes along with the first voltage signal in size.
The subtraction circuit block 500 includes:
an operational amplifier 510; preferably, the operational amplifier 510 is LF 353.
The non-inverting input end of the operational amplifier is connected with a first branch 520 and a second branch 530 which are connected in parallel:
the inverting input end of the operational amplifier is connected with a third branch 540 and a fourth branch 550;
a first resistor 521 is connected in series on the first branch for accessing a first voltage signal or a second voltage signal;
a second resistor 531 is connected in series on the second branch for grounding;
a third resistor 541 is connected in series to the third branch for receiving the offset signal output by the sample-and-hold circuit module;
a fourth resistor 551 is connected in series to the fourth branch, and the other end of the fourth branch is connected to the output end of the operational amplifier.
When the control module outputs the first control signal with high level, the sample-and-hold amplifier is in a hold state, and the magnitude of the offset signal output by the sample-and-hold circuit module is equal to the magnitude of the first voltage signal, preferably equal to the magnitude of the first voltage signal at the moment when the triode is turned on, that is, the magnitude of the instantaneous voltage signal jumping to high level. The offset signal is input to a third branch. When the stress application test is carried out, the first branch of the subtraction circuit inputs a second voltage signal. At this time, since the second voltage signal includes the boost signal and the first voltage signal, and the offset signal has a magnitude equal to that of the first voltage signal, in the subtraction circuit, the second voltage signal and the offset signal pass through the operational amplifier 510, and the obtained boost signal is output from the output terminal of the operational amplifier 510.
When no signal deviation exists, the control module controls the piezoelectric measuring equipment to perform stress application test because the intermediate partial pressure value is within the preset range, and outputs high level to enable the sample-hold circuit module to enter a hold state, and the deviation signal is 0 at the moment. I.e., the offset to ground signal is 0. At this time, the second voltage signal connected to the first branch of the subtraction circuit is output from the output terminal as the boost signal.
When the control module outputs the second control signal with low level, the sampling holding amplifier is in an adopted state and changes according to the size of the first voltage signal. At the moment, the piezoelectric coefficient measuring equipment does not perform stress application test under the control of the control module, the first voltage signal is input by the first branch, the offset signal input by the third branch is equal to the first voltage signal, and the stress application signal obtained by the subtraction circuit module is zero.
The circuit further comprises: the level boost circuit module 600 is electrically connected to the subtraction circuit module 500 and the control module 300, and is configured to boost the level of the boost signal and output the boosted level to the control module.
The level lifting circuit module can effectively lift the stress application signal into positive voltage, so that on one hand, the identification requirement of the control module is met, the control module is convenient to acquire digital or analog signals, and on the other hand, the waveform of the voltage signal is integrally lifted.
The present application relates to a method for canceling a signal offset of a charge amplifier, the method comprising:
the front circuit outputs a first voltage signal according to a first charge signal generated before the stress application test;
the monitoring circuit outputs a monitoring signal according to the first voltage signal;
when the monitoring signal meets a preset condition, the control module outputs a first control signal to the sampling hold circuit; meanwhile, the control module controls the piezoelectric coefficient measuring equipment to perform stress application test;
the sampling holding circuit outputs an offset signal to the subtraction circuit according to the first control signal and the first voltage signal, and keeps the magnitude of the offset signal unchanged within a certain time;
the front circuit outputs a second voltage signal to the subtraction circuit according to a second charge signal generated in the stress application test;
and the subtraction circuit outputs a force application signal according to the second voltage signal and the offset signal.
Variations and modifications to the above-described embodiments may occur to those skilled in the art, which fall within the scope and spirit of the above description. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and variations of the present invention should fall within the scope of the claims of the present invention. Furthermore, although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.
Claims (10)
1. A circuit for canceling charge amplifier signal offset, the circuit comprising:
the monitoring circuit module is electrically connected with the front circuit module;
the control module is electrically connected with the monitoring circuit module;
the sampling and holding circuit module is electrically connected with the control module;
the subtraction circuit module is electrically connected with the sampling and holding circuit module;
the sampling hold circuit module and the subtraction circuit module are also electrically connected with the front circuit module;
the front circuit module is used for outputting a first voltage signal according to a first charge signal, and the first charge signal is generated before variable testing;
the monitoring circuit module is used for outputting a monitoring signal to the control module according to the first voltage signal;
the control module is used for outputting a first control signal to the sample-and-hold circuit module when the monitoring signal meets a preset condition;
the sampling and holding circuit module is used for outputting an offset signal to the subtraction circuit module according to the first control signal and the first voltage signal, and keeping the magnitude of the offset signal unchanged within a certain time;
the control module is also used for controlling the measuring equipment electrically connected with the monitoring signal to carry out variable test when the monitoring signal meets the preset condition;
the front circuit module is further configured to output a second voltage signal to the subtraction circuit module according to a second charge signal, where the second charge signal is generated in a variable test process;
and the subtraction circuit module is used for outputting a variable signal according to the second voltage signal and the offset signal.
2. The circuit of claim 1, further comprising:
and the level lifting circuit module is electrically connected with the subtraction circuit module and the control module and is used for lifting the level of the variable signal and outputting the level to the control module.
3. The circuit of claim 1, wherein:
the control module is also used for outputting a second control signal to the sample-and-hold circuit module when the monitoring signal meets the condition which is not preset;
and the sampling and holding circuit module is used for entering a sampling state according to the second control signal and outputting an offset signal according to the second control signal and the first voltage signal.
4. The circuit of claim 3, wherein:
the control module is also used for controlling the measuring equipment not to carry out variable test when the monitoring signal does not accord with the preset condition;
and the subtraction circuit module is used for outputting a variable signal according to the first voltage signal and the offset signal, wherein the variable signal is zero at the moment.
5. The circuit of claim 1, wherein:
the monitoring circuit module comprises a voltage division circuit;
the monitoring signal is an intermediate voltage division value of the voltage division circuit,
the preset condition is that the intermediate partial pressure value is within a preset range;
the control module is configured to output the first control signal when the obtained intermediate voltage division value is within a preset range: and when the obtained intermediate partial pressure value is within a preset range, controlling the measuring equipment to carry out variable testing.
6. The circuit of claim 5, wherein the monitoring circuit module comprises:
the voltage division circuit comprises a first end, a second end and two resistors connected between the first end and the second end;
the first end inputs a preset fixed voltage;
the second end is connected with the front circuit module to access the first voltage signal;
and a third end is connected between the two resistors, and the monitoring signal is output to the control module through the third end.
7. The circuit of any of claims 1-4, wherein the sample-and-hold circuit block comprises:
the input end of the sample-hold amplifier is connected with the first voltage signal, and the output end of the sample-hold amplifier is connected with the subtraction circuit module:
and the base electrode of the triode is connected with the first control signal, the collector electrode is connected with a positive voltage, the emitter electrode is grounded, and the collector electrode is also connected with the logic end of the sample-hold amplifier.
8. The circuit of claim 1, wherein:
the first control signal is at a high level;
when a high level is input, the triode of the sample-and-hold circuit module is conducted, at the moment, the sample-and-hold amplifier is in a hold state, and the offset signal output by the output end of the sample-and-hold amplifier is the same as the first voltage signal in the conduction moment of the triode.
9. The circuit of claim 3 or 4, wherein:
the second control signal is at a low level;
when the control signal is at a low level, the triode of the sample-and-hold circuit module is turned off, at the moment, the sample-and-hold amplifier is in a sampling state, and the offset signal output by the output end of the sample-and-hold amplifier is the same as the first voltage signal in size and changes along with the first voltage signal in size.
10. The circuit of claim 1, wherein the subtraction circuit block comprises:
an operational amplifier;
the non-inverting input end of the operational amplifier is connected with a first branch and a second branch which are connected in parallel:
the reverse input end of the operational amplifier is connected with a third branch and a fourth branch;
the first branch is connected with a first resistor in series and used for accessing a first voltage signal or a second voltage signal;
a second resistor is connected in series on the second branch circuit and is used for grounding;
a third resistor is connected in series on the third branch and used for accessing an offset signal output by the sample-and-hold circuit module;
and a fourth resistor is connected in series on the fourth branch, and the other end of the fourth branch is connected with the output end of the operational amplifier.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110799565.0A CN113489466B (en) | 2021-07-15 | 2021-07-15 | Circuit for eliminating signal offset of charge amplifier |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
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| CN202110799565.0A CN113489466B (en) | 2021-07-15 | 2021-07-15 | Circuit for eliminating signal offset of charge amplifier |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114285385A (en) * | 2022-02-21 | 2022-04-05 | 成都芯翼科技有限公司 | Offset circuit of operational amplifier input current |
| CN117294262A (en) * | 2023-08-15 | 2023-12-26 | 北京思凌科半导体技术有限公司 | Arithmetic circuit and test circuit |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR940003386A (en) * | 1992-07-24 | 1994-02-21 | 양승택 | TV codec device for NTSC line with DS3 transmission speed |
| US6456954B1 (en) * | 1999-02-24 | 2002-09-24 | Denso Corporation | Sensing apparatus for detecting a physical quantity, including memory circuits storing characteristics adjusting data |
| US20050275446A1 (en) * | 2004-06-15 | 2005-12-15 | Bae Systems Information And Electronic Systems Integration Inc. | Automatic integration reset offset subtraction circuit |
| CN101040441A (en) * | 2004-10-12 | 2007-09-19 | 索尼株式会社 | Sample hold circuit, and pipeline ad converter using the circuit |
| US20090201051A1 (en) * | 2004-10-12 | 2009-08-13 | Koichi Ono | Sample-and-Hold Circuit and Pipeline Ad Converter Using Same |
| JP2010087542A (en) * | 2008-09-29 | 2010-04-15 | Toshiba Corp | Amplifier circuit |
| CN101882929A (en) * | 2010-06-30 | 2010-11-10 | 中国电子科技集团公司第五十八研究所 | Input common mode voltage offset compensation circuit of pipelined analog-to-digital converter |
| JP2014142303A (en) * | 2013-01-25 | 2014-08-07 | Renesas Electronics Corp | Semiconductor device and semiconductor testing system |
| CN108680778A (en) * | 2018-03-22 | 2018-10-19 | 河南科技大学 | A kind of portable waveform is shown and signal generation apparatus |
-
2021
- 2021-07-15 CN CN202110799565.0A patent/CN113489466B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR940003386A (en) * | 1992-07-24 | 1994-02-21 | 양승택 | TV codec device for NTSC line with DS3 transmission speed |
| US6456954B1 (en) * | 1999-02-24 | 2002-09-24 | Denso Corporation | Sensing apparatus for detecting a physical quantity, including memory circuits storing characteristics adjusting data |
| US20050275446A1 (en) * | 2004-06-15 | 2005-12-15 | Bae Systems Information And Electronic Systems Integration Inc. | Automatic integration reset offset subtraction circuit |
| CN101040441A (en) * | 2004-10-12 | 2007-09-19 | 索尼株式会社 | Sample hold circuit, and pipeline ad converter using the circuit |
| US20090201051A1 (en) * | 2004-10-12 | 2009-08-13 | Koichi Ono | Sample-and-Hold Circuit and Pipeline Ad Converter Using Same |
| JP2010087542A (en) * | 2008-09-29 | 2010-04-15 | Toshiba Corp | Amplifier circuit |
| CN101882929A (en) * | 2010-06-30 | 2010-11-10 | 中国电子科技集团公司第五十八研究所 | Input common mode voltage offset compensation circuit of pipelined analog-to-digital converter |
| JP2014142303A (en) * | 2013-01-25 | 2014-08-07 | Renesas Electronics Corp | Semiconductor device and semiconductor testing system |
| CN108680778A (en) * | 2018-03-22 | 2018-10-19 | 河南科技大学 | A kind of portable waveform is shown and signal generation apparatus |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114285385A (en) * | 2022-02-21 | 2022-04-05 | 成都芯翼科技有限公司 | Offset circuit of operational amplifier input current |
| CN114285385B (en) * | 2022-02-21 | 2022-06-03 | 成都芯翼科技有限公司 | Offset circuit of operational amplifier input current |
| CN117294262A (en) * | 2023-08-15 | 2023-12-26 | 北京思凌科半导体技术有限公司 | Arithmetic circuit and test circuit |
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|---|---|
| CN113489466B (en) | 2023-12-22 |
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