AC analog quantity signal band-pass filtering device

By designing an AC analog signal bandpass filtering device including a voltage divider circuit, a voltage follow circuit and a proportional amplifier, the problems of complexity and temperature drift of the bandpass filtering circuit in the prior art are solved, and a simpler configuration and more stable filtering effect are achieved.

CN222750408UActive Publication Date: 2025-04-11CERI DIGITAL TECHNOLOGY (BEIJING) CO LTD +1
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Patent Information

Application Number
CN202421500295.4
Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
Filing Date
2024-06-27
Publication Date
2025-04-11
Estimated Expiration
2034-06-27

AI Technical Summary

Technical Problem

When implementing bandpass filtering of AC analog signal, existing bandpass filtering circuits require complex resistance configurations and have strict requirements on resistance value accuracy. Temperature changes will cause resistance value to drift, increasing system complexity.

Method used

An alternating analog signal band-pass filtering device including a voltage divider circuit, a voltage follow circuit and a proportional amplifier is designed. The band-pass filtering of the signal is realized through voltage divider processing, voltage follow and proportional amplification, and the design of integrated resistor and operational amplifiers is reduced.

Benefits of technology

It reduces the complex configuration of the bandpass filter module, reduces the drift of temperature to resistor value, and improves the stability and reliability of the system.

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Abstract

The utility model discloses an AC analog quantity signal band-pass filtering device, and relates to the technical field of electronic circuits. The alternating-current analog quantity signal band-pass filtering device comprises a voltage division circuit, a voltage following circuit and a proportional amplifier, wherein the input end of the voltage division circuit is used for receiving an alternating current analog quantity input signal, and the output end of the voltage division circuit is connected with the input end of the voltage following circuit; the output end of the voltage follower circuit is connected with the input end of the proportional amplifier, and the output end of the proportional amplifier outputs an alternating-current analog quantity output signal; the voltage division circuit is used for carrying out voltage division processing on the alternating current analog quantity input signal; the voltage following circuit is used for buffering the AC analog input signal after voltage division; and the proportional amplifier is used for proportionally amplifying the buffered AC analog input signal. According to the utility model, alternating current analog quantity signal band-pass filtering can be realized while the complexity configuration of the band-pass filtering module is reduced, and the drifting of the resistance value caused by temperature is reduced.
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Description

Technical Field

[0001] The utility model relates to the field of electronic circuits, in particular to an AC analog signal bandpass filtering device. Background Art

[0002] This section is intended to provide a background or context to the embodiments of the utility model recited in the claims. The description herein is not admitted to be prior art by inclusion in this section.

[0003] When filtering AC analog signals, a dedicated filter chip is usually used. The filter chip is configured through resistors to filter signals in different frequency bands. If bandpass filtering is to be achieved, high-order low-pass filters and high-pass filters are required to cascade the signal to achieve a complete bandpass filter circuit.

[0004] However, the advanced filter chip used in the existing bandpass filter circuit requires complex resistor configuration and has strict requirements on the resistance value accuracy, otherwise normal bandpass filtering cannot be achieved. Therefore, how to provide an AC analog signal bandpass filter device to reduce the drift of the resistance value caused by temperature while reducing the complexity of the bandpass filter module configuration is a problem that technicians in this field need to solve urgently. Utility Model Content

[0005] In the embodiment of the utility model, an AC analog signal bandpass filter device is proposed, which can reduce the complexity of the bandpass filter module configuration and reduce the drift of the resistance value caused by temperature; it includes: a voltage divider circuit, a voltage follower circuit and a proportional amplifier;

[0006] The input end of the voltage divider circuit is used to receive an AC analog input signal, and the output end of the voltage divider circuit is connected to the input end of the voltage follower circuit; the output end of the voltage follower circuit is connected to the input end of the proportional amplifier, and the output end of the proportional amplifier outputs an AC analog output signal;

[0007] The voltage divider circuit is used to perform voltage division processing on the AC analog input signal; the voltage follower circuit is used to perform buffer processing on the AC analog input signal after the voltage division processing; and the proportional amplifier is used to proportionally amplify the AC analog input signal after the buffer processing.

[0008] Further, the voltage divider circuit includes a first resistor and a second resistor;

[0009] The first end of the first resistor is the input end of the voltage divider circuit; the second end of the first resistor is the output end of the voltage divider circuit; the second end of the first resistor is connected to the first end of the second resistor; and the second end of the second resistor is grounded.

[0010] Furthermore, the resistance value of the first resistor is 18 kΩ; the resistance value of the second resistor is 2 kΩ.

[0011] Further, the voltage follower circuit includes a third resistor and a first operational amplifier;

[0012] Among them, the first end of the third resistor is the input end of the voltage follower circuit, the second end of the third resistor is connected to the positive input end of the first operational amplifier, the negative input end of the first operational amplifier is connected to the output end of the first operational amplifier, and the output end of the first operational amplifier is the output end of the voltage follower circuit.

[0013] Furthermore, the resistance of the third resistor is 24 kΩ.

[0014] Further, the proportional amplifier includes a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor and a second operational amplifier;

[0015] The first end of the fourth resistor is connected to a reference voltage source; the second end of the fourth resistor is connected to a positive input end of the second operational amplifier; the first end of the fifth resistor is an input end of a proportional amplifier (3); the second end of the fifth resistor is connected to a positive input end of the second operational amplifier; the first end of the sixth resistor is connected to a negative input end of the second operational amplifier; the second end of the sixth resistor is grounded; the first end of the seventh resistor is connected to a negative input end of the second operational amplifier; and the second end of the seventh resistor is connected to an output end of the second operational amplifier.

[0016] Further, the resistance value of the fourth resistor is 24 kΩ; the resistance value of the fifth resistor is 24 kΩ; the resistance value of the sixth resistor is 24 kΩ; and the resistance value of the seventh resistor is 24 kΩ.

[0017] Furthermore, the reference voltage source is 1.5V.

[0018] Further, the fourth resistor, the fifth resistor, the sixth resistor, and the seventh resistor form an integrated resistor.

[0019] Furthermore, the first operational amplifier and the second operational amplifier are soldered on the same circuit board.

[0020] The AC analog signal bandpass filtering device of the utility model embodiment includes: a voltage divider circuit, a voltage follower circuit and a proportional amplifier; wherein the input end of the voltage divider circuit is used to receive the AC analog input signal, and the output end of the voltage divider circuit is connected to the input end of the voltage follower circuit; the output end of the voltage follower circuit is connected to the input end of the proportional amplifier, and the output end of the proportional amplifier outputs the AC analog output signal; the voltage divider circuit is used to perform voltage division processing on the AC analog input signal; the voltage follower circuit is used to perform buffer processing on the AC analog input signal after the voltage division processing; the proportional amplifier is used to amplify the buffered AC analog input signal in proportion. The utility model embodiment can realize the bandpass filtering of the AC analog signal while reducing the complexity configuration of the bandpass filtering module, and reduce the drift of the resistance value caused by temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0022] Figure 1 It is a schematic diagram of the AC analog signal bandpass filtering device provided in an embodiment of the utility model.

[0023] Figure 2 The present invention is a circuit diagram of an AC analog signal bandpass filter device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the embodiment of the utility model more clear, the embodiment of the utility model is further described in detail below in conjunction with the accompanying drawings. Here, the illustrative embodiment of the utility model and its description are used to explain the utility model, but are not used as a limitation of the utility model.

[0025] The term "and / or" herein only describes an association relationship, indicating that three relationships may exist. For example, A and / or B may represent the following three situations: A exists alone, A and B exist at the same time, and B exists alone. In addition, the term "at least one" herein represents any combination of at least two of any one or more of a plurality of. For example, including at least one of A, B, and C may represent including any one or more elements selected from the set consisting of A, B, and C.

[0026] In the description of this specification, the terms "include", "including", "have", "contain", etc. are all open terms, which mean including but not limited to. The descriptions with reference to the terms "one embodiment", "a specific embodiment", "some embodiments", "for example", etc. mean that the specific features, structures or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. The order of steps involved in each embodiment is used to schematically illustrate the implementation of the present application, and the order of steps is not limited and can be appropriately adjusted as needed.

[0027] Figure 1 Schematic diagram of the AC analog signal bandpass filter device provided in the embodiment of the utility model. Figure 1 As shown, the AC analog signal bandpass filtering device comprises: a voltage divider circuit 1, a voltage follower circuit 2 and a proportional amplifier 3;

[0028] The input end of the voltage divider circuit 1 is used to receive an AC analog input signal, and the output end of the voltage divider circuit 1 is connected to the input end of the voltage follower circuit 2; the output end of the voltage follower circuit 2 is connected to the input end of the proportional amplifier 3, and the output end of the proportional amplifier 3 outputs an AC analog output signal;

[0029] The voltage divider circuit 1 is used to perform voltage division processing on the AC analog input signal; the voltage follower circuit 2 is used to perform buffer processing on the AC analog input signal after the voltage division processing; and the proportional amplifier 3 is used to proportionally amplify the AC analog input signal after the buffer processing.

[0030] Figure 2 The present invention is a circuit diagram of an AC analog signal bandpass filter device provided in an embodiment of the present invention.

[0031] In one embodiment, reference Figure 2 , the voltage divider circuit 1 includes a first resistor R1 and a second resistor R2;

[0032] Among them, the first end 11 of the first resistor R1 is the input end of the voltage divider circuit 1; the second end 12 of the first resistor R1 is the output end of the voltage divider circuit 1; the second end 12 of the first resistor R1 is connected to the first end 13 of the second resistor R2; the second end 14 of the second resistor R2 is grounded.

[0033] In a specific implementation, the first end 11 of the first resistor R1 receives the AC analog input signal Ai, and the AC analog input signal Ai enters the input end of the voltage follower circuit 2 after being divided by the first resistor R1 and the second resistor R2.

[0034] In one embodiment, the resistance of the first resistor R1 is 18 kΩ; the resistance of the second resistor R2 is 2 kΩ.

[0035] In one embodiment, reference Figure 2 , the voltage follower circuit 2 includes a third resistor R3 and a first operational amplifier U1;

[0036] Among them, the first end 21 of the third resistor R3 is the input end of the voltage follower circuit 2, the second end 22 of the third resistor R3 is connected to the positive input end 23 of the first operational amplifier, the negative input end 24 of the first operational amplifier U1 is connected to the output end 25 of the first operational amplifier U1, and the output end 25 of the first operational amplifier U1 is the output end of the voltage follower circuit 2.

[0037] In specific implementation, the third resistor R3 and the first operational amplifier U1 form a voltage follower circuit. After the divided AC analog input signal Ai passes through the voltage follower circuit, the load effect can be eliminated, laying a foundation for subsequent signal processing.

[0038] In one embodiment, the resistance of the third resistor is 24 kΩ.

[0039] It should be noted that the first operational amplifier U1 is powered by a bipolar power supply, with a positive voltage of +15V and a negative voltage of -15V.

[0040] In one embodiment, reference Figure 2 , the proportional amplifier 3 includes a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7 and a second operational amplifier U2;

[0041] Among them, the first end 31 of the fourth resistor R4 is connected to the reference voltage source; the second end 32 of the fourth resistor R4 is connected to the positive input terminal 33 of the second operational amplifier U2; the first end 36 of the fifth resistor R5 is the input terminal of the proportional amplifier 3; the second end 37 of the fifth resistor R5 is connected to the positive input terminal 33 of the second operational amplifier U2; the first end 38 of the sixth resistor R6 is connected to the negative input terminal 34 of the second operational amplifier U2; the second end 39 of the sixth resistor R6 is grounded; the first end 40 of the seventh resistor R7 is connected to the negative input terminal 34 of the second operational amplifier U2; the second end 41 of the seventh resistor R7 is connected to the output terminal 35 of the second operational amplifier.

[0042] In one embodiment, the resistance value of the fourth resistor is 24 kΩ; the resistance value of the fifth resistor is 24 kΩ; the resistance value of the sixth resistor is 24 kΩ; and the resistance value of the seventh resistor is 24 kΩ.

[0043] In one embodiment, the reference voltage source is 1.5V.

[0044] In the specific implementation, a reference voltage source of 1.5V is used as a reference source. After the reference source is divided by the fourth resistor R4, it is connected to the positive input terminal 33 of the second operational amplifier U2. The buffered AC analog input signal is amplified proportionally by the second operational amplifier U2 to output an analog signal, the AC analog input signal Ao, with an amplitude range of 0 to 3V.

[0045] In one embodiment, the fourth resistor R4, the fifth resistor R5, the sixth resistor R6, and the seventh resistor R7 form an integrated resistor, which can further reduce the drift of the resistance value caused by temperature.

[0046] In one embodiment, the first operational amplifier and the second operational amplifier are soldered on the same circuit board, which ensures that the characteristics of the operational amplifiers are completely consistent, reduces the zero drift problem of the front and rear operational amplifiers, and also avoids the influence of external temperature on the two operational amplifiers. In specific implementation, a dual operational amplifier chip can be selected.

[0047] The resistor used in the embodiment of the utility model is of a common type, which expands the practical scope of the utility model.

[0048] In summary, the AC analog signal bandpass filtering device of the embodiment of the utility model includes: a voltage divider circuit, a voltage follower circuit and a proportional amplifier; wherein the input end of the voltage divider circuit is used to receive the AC analog input signal, and the output end of the voltage divider circuit is connected to the input end of the voltage follower circuit; the output end of the voltage follower circuit is connected to the input end of the proportional amplifier, and the output end of the proportional amplifier outputs the AC analog output signal; the voltage divider circuit is used to perform voltage division processing on the AC analog input signal; the voltage follower circuit is used to perform buffer processing on the AC analog input signal after the voltage division processing; the proportional amplifier is used to amplify the buffered AC analog input signal in proportion. The embodiment of the utility model can realize the bandpass filtering of the AC analog signal while reducing the complexity configuration of the bandpass filtering module, and reduce the drift of the resistance value caused by temperature.

[0049] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the utility model in detail. It should be understood that the above description is only a specific embodiment of the utility model and is not intended to limit the scope of protection of the utility model. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the utility model should be included in the scope of protection of the utility model.

Claims

1. An AC analog signal bandpass filtering device, characterized in that: include: A voltage divider circuit (1), a voltage follower circuit (2) and a proportional amplifier (3); The input end of the voltage divider circuit (1) is used to receive an AC analog input signal, and the output end of the voltage divider circuit (1) is connected to the input end of the voltage follower circuit (2); the output end of the voltage follower circuit (2) is connected to the input end of the proportional amplifier (3), and the output end of the proportional amplifier (3) outputs an AC analog output signal; The voltage divider circuit (1) is used to perform voltage division processing on an AC analog input signal; the voltage follower circuit (2) is used to perform buffer processing on the AC analog input signal after the voltage division processing; and the proportional amplifier (3) is used to proportionally amplify the AC analog input signal after the buffer processing.

2. The AC analog signal bandpass filtering device according to claim 1, characterized in that: The voltage divider circuit (1) comprises a first resistor and a second resistor; The first end of the first resistor is the input end of the voltage divider circuit (1); the second end of the first resistor is the output end of the voltage divider circuit (1); the second end of the first resistor is connected to the first end of the second resistor; and the second end of the second resistor is grounded.

3. The AC analog signal bandpass filtering device according to claim 2, characterized in that: The resistance value of the first resistor is 18 kΩ; the resistance value of the second resistor is 2 kΩ.

4. The AC analog signal bandpass filtering device according to claim 1, characterized in that: The voltage follower circuit (2) comprises a third resistor and a first operational amplifier; The first end of the third resistor is the input end of the voltage follower circuit (2), the second end of the third resistor is connected to the positive input end of the first operational amplifier, the negative input end of the first operational amplifier is connected to the output end of the first operational amplifier, and the output end of the first operational amplifier is the output end of the voltage follower circuit (2).

5. The AC analog signal bandpass filtering device according to claim 4, characterized in that: The resistance of the third resistor is 24 kΩ.

6. The AC analog signal bandpass filtering device according to claim 4, characterized in that: The proportional amplifier (3) comprises a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor and a second operational amplifier; The first end of the fourth resistor is connected to a reference voltage source; the second end of the fourth resistor is connected to the positive input end of the second operational amplifier; the first end of the fifth resistor is the input end of the proportional amplifier (3); the second end of the fifth resistor is connected to the positive input end of the second operational amplifier; the first end of the sixth resistor is connected to the negative input end of the second operational amplifier; the second end of the sixth resistor is grounded; the first end of the seventh resistor is connected to the negative input end of the second operational amplifier; the second end of the seventh resistor is connected to the output end of the second operational amplifier; and the output end of the second operational amplifier is the output end of the proportional amplifier (3).

7. The AC analog signal bandpass filtering device according to claim 6, characterized in that: The resistance value of the fourth resistor is 24 kΩ; the resistance value of the fifth resistor is 24 kΩ; the resistance value of the sixth resistor is 24 kΩ; and the resistance value of the seventh resistor is 24 kΩ.

8. The AC analog signal bandpass filtering device according to claim 6, characterized in that: The reference voltage source is 1.5V.

9. The AC analog signal bandpass filtering device according to claim 6, characterized in that: The fourth resistor, the fifth resistor, the sixth resistor and the seventh resistor form an integrated resistor.

10. The AC analog signal bandpass filtering device according to claim 6, characterized in that: The first operational amplifier and the second operational amplifier are soldered on the same circuit board.