CN219145352U

CN219145352U - Novel range switching circuit of charge amplifier

Info

Publication number: CN219145352U
Application number: CN202223533988.7U
Authority: CN
Inventors: 章志光; 郑大伟
Original assignee: Yangzhou Kedong Electronics Co ltd
Current assignee: Yangzhou Kedong Electronics Co ltd
Priority date: 2022-12-29
Filing date: 2022-12-29
Publication date: 2023-06-06
Anticipated expiration: 2032-12-29

Abstract

The utility model discloses a range switching circuit of a novel charge amplifier, which comprises a first integrating capacitor C1, a second integrating capacitor C2, a third integrating capacitor C3, an operational amplifier U1, a first switch P1, a second switch P2, a first resistor R1, a second resistor R2 and a third resistor R3. The utility model belongs to the technical field of amplifiers, and particularly provides a novel range switching circuit of a charge amplifier, which controls the impedance of an input end of the operational amplifier through a combined switch of a first switch and a second switch, optimizes a feedback network of the charge amplifier, improves the impedance of an input part, and reduces the lower limit frequency of a charge pre-stage.

Description

Novel range switching circuit of charge amplifier

Technical Field

The utility model belongs to the technical field of amplifiers, and particularly relates to a range switching circuit of a novel charge amplifier.

Background

A charge amplifier is widely used as a conversion circuit for a sensor (e.g., a piezoelectric sensor, a photoelectric sensor, etc.) as an amplifier for directly converting a charge into a voltage signal.

The ideal amplifier has no balance resistor, but with the transformation of the external environment, the integral charge on the capacitor can be increased, so that the output is transformed, drift is generated, and the testing precision is affected. Therefore, as shown in fig. 1, the conventional charge amplifier is composed of an operational amplifier, an integrating capacitor C and a balancing resistor R, the integrating capacitor C and the balancing resistor R are connected in parallel and then connected across the negative input terminal and the output terminal of the operational amplifier, and in the switching circuit, the conventional scheme is to add electronic switches at two ends of the capacitor for switching the gear of the charge amplifier, and the influence is larger when measuring the low-frequency charge signal due to lower insulation resistance of the electronic switches.

Disclosure of Invention

Aiming at the situation, in order to overcome the defects of the prior art, the utility model provides a novel range switching circuit of the charge amplifier, which controls the impedance of the input end of the operational amplifier through the combined switch of the first switch and the second switch, optimizes the feedback network of the charge amplifier, improves the impedance of the input part, and reduces the lower limit frequency of the charge pre-stage.

The technical scheme adopted by the utility model is as follows: the utility model discloses a range switching circuit of a novel charge amplifier, which comprises a first integrating capacitor C1, a second integrating capacitor C2, a third integrating capacitor C3, an operational amplifier U1, a first switch P1, a second switch P2, a first resistor R1, a second resistor R2 and a third resistor R3, wherein the first resistor R1, the second resistor R2 and the third resistor R3 are connected in series, the first integrating capacitor C1, the second integrating capacitor C2 and the third integrating capacitor C3 are connected in series, the first resistor R1, the second resistor R2 and the third resistor R3 which are connected in series are connected in parallel with the first integrating capacitor C1, the second integrating capacitor C2 and the third integrating capacitor C3 which are connected in series, two ends of the first resistor R1 are respectively connected with an output end of the operational amplifier U1, one end of the first switch P1 is arranged between the first resistor R1 and the second resistor R2, the other end of the first switch P1 is connected with the output end of the operational amplifier U1, and the other end of the second switch P2 is connected with the third resistor R3.

Further, when the first switch P1 is turned off and the second switch P2 is turned off, the first range switching circuit is provided.

Preferably, the first switch P1 is turned on and the second switch P2 is turned off, which is a second range switching circuit.

Further, the first switch P1 is turned off and the second switch P2 is turned on, which is a third range switching circuit.

Further, when the first switch P1 is turned on and the second switch P2 is turned on, the fourth range switching circuit is provided.

In a preferred embodiment, the impedance of the input end of the operational amplifier U1 is controlled by the combined switch of the first switch P1 and the second switch P2.

The utility model has the following beneficial effects by adopting the structure:

1. the feedback network of the charge amplifier is optimized, the charges generated by the piezoelectric sensor are converted into proportional voltages, the impedance of an input part is improved, and the lower limit frequency of a charge pre-stage is reduced;

2. the design of the scheme is beneficial to the control of computer software.

Drawings

FIG. 1 is a schematic diagram of a prior art charge amplifier range switching circuit;

fig. 2 is a schematic structural diagram of a range switching circuit of the novel charge amplifier according to the present disclosure.

The accompanying drawings are included to provide a further understanding of the utility model and are incorporated in and constitute a part of this specification, illustrate the utility model and together with the embodiments of the utility model, serve to explain the utility model.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the utility model; all other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

As shown in fig. 2, the range switching circuit of the novel charge amplifier of the present utility model includes a first integrating capacitor C1, a second integrating capacitor C2, a third integrating capacitor C3, an operational amplifier U1, a first switch P1, a second switch P2, a first resistor R1, a second resistor R2, and a third resistor R3, wherein the first resistor R1, the second resistor R2, and the third resistor R3 are connected in series, the first integrating capacitor C1, the second integrating capacitor C2, and the third integrating capacitor C3 are connected in series, the first resistor R1, the second resistor R2, and the third resistor R3 connected in series are connected in parallel with the first integrating capacitor C1, the second integrating capacitor C2, and the third integrating capacitor C3, and both ends of the first resistor R1, the second resistor R2, and the third resistor R3 are respectively connected with an output end, one end of the first switch P1 is disposed between the first resistor R1 and the second resistor R2, and the other end of the second switch P1 is connected with an output end of the operational amplifier U1, and the other end of the second switch P2 is disposed between the second resistor R2 and the output end of the third resistor U1.

In this scheme, the impedance of the input end of the operational amplifier U1 is controlled by the combined switch of the first switch P1 and the second switch P2. The combined switch of the first switch P1 and the second switch P2 comprises 4 states, and the first range switching circuit is used when the first switch P1 is disconnected and the second switch P2 is disconnected. The first switch P1 is turned on and the second switch P2 is turned off, which are second range switching circuits. The third range switching circuit is configured when the first switch P1 is turned off and the second switch P2 is turned on. The fourth range switching circuit is a fourth range switching circuit when the first switch P1 is turned on and the second switch P2 is turned on.

It is noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Although embodiments of the present utility model have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and spirit of the utility model, the scope of which is defined in the appended claims and their equivalents.

The utility model and its embodiments have been described above with no limitation, and the actual construction is not limited to the embodiments of the utility model as shown in the drawings. In summary, if one of ordinary skill in the art is informed by this disclosure, a structural manner and an embodiment similar to the technical solution should not be creatively devised without departing from the gist of the present utility model.

Claims

1. A novel range switching circuit of a charge amplifier is characterized in that: the integrated circuit comprises a first integrating capacitor C1, a second integrating capacitor C2, a third integrating capacitor C3, an operational amplifier U1, a first switch P1, a second switch P2, a first resistor R1, a second resistor R2 and a third resistor R3, wherein the first resistor R1, the second resistor R2 and the third resistor R3 are connected in series, the first integrating capacitor C1, the second integrating capacitor C2 and the third integrating capacitor C3 are connected in series, the first resistor R1, the second resistor R2 and the third resistor R3 which are connected in series are connected in parallel with the first integrating capacitor C1, the second integrating capacitor C2 and the third integrating capacitor C3 which are connected in series, two ends of the first switch P1 are respectively connected with an inverted input end and an output end of the operational amplifier U1, one end of the first switch P1 is arranged between the first resistor R1 and the second resistor R2, the other end of the second switch P2 is connected with an output end of the operational amplifier U1, and one end of the second switch P2 is arranged between the second resistor R2 and the third resistor R3 and the output end of the operational amplifier U1 is connected with the other end of the operational amplifier.

2. The range switching circuit of a novel charge amplifier as set forth in claim 1, wherein: when the first switch P1 is turned off and the second switch P2 is turned off, the first range switching circuit is provided.

3. The range switching circuit of a novel charge amplifier as set forth in claim 2, wherein: the first switch P1 is turned on and the second switch P2 is turned off, which are second range switching circuits.

4. A novel charge amplifier range switching circuit as set forth in claim 3, wherein: the third range switching circuit is configured when the first switch P1 is turned off and the second switch P2 is turned on.

5. The range switching circuit of a novel charge amplifier as set forth in claim 4, wherein: the fourth range switching circuit is a fourth range switching circuit when the first switch P1 is turned on and the second switch P2 is turned on.

6. The range switching circuit of a novel charge amplifier as set forth in claim 5, wherein: and controlling the impedance of the input end of the operational amplifier U1 through the combined switch of the first switch P1 and the second switch P2.