Active noise reduction microphone circuit structure

Abstract

The utility model discloses an active noise reduction microphone circuit structure which is built in a microphone and comprises a pre-amplification circuit, an ADC analog-to-digital conversion circuit and a DSP circuit, the pre-amplification circuit is electrically connected with a pickup MIC, the ADC analog-to-digital conversion circuit is connected with the pre-amplification circuit, and the DSP circuit is connected with the ADC analog-to-digital conversion circuit. The product is arranged in the microphone, the pre-amplification circuit, the ADC analog-to-digital conversion circuit and the DSP circuit are arranged in a matched mode, audio signals are picked up through the pickup MIC40, then enter the pre-amplification circuit to be pre-amplified and then enter the ADC analog-to-digital conversion circuit to be subjected to analog-to-digital conversion into IIS digital signals, and the IIS digital signals are output to a chip of the DSP circuit to be subjected to noise reduction processing. Therefore, the active noise reduction function is achieved, an external device does not need to be connected, and use is more convenient.

Description

Technical Field

[0001] The utility model relates to microphone field technology, in particular to an active noise reduction microphone circuit structure. Background Art

[0002] A microphone is a device used to collect environmental sound on site and transmit it to the back-end equipment. It is composed of a microphone housing, a microphone MIC, and an audio amplifier circuit. In actual work, the use of microphones is very purposeful. In other words, whether the technical indicators or characteristics of the microphone are ideal depends on the purpose of its use in a certain environment. Despite this, each microphone has basic design characteristics and technical indicators. Common technical indicators include: sensitivity, frequency response, equivalent sound pressure level, directivity, dynamic range, maximum sound pressure level, and output impedance. The directivity of a microphone is also called the directivity of a microphone. It refers to the response of a microphone to sound pressure at different incident angles. Specifically, when sound waves are incident on the diaphragm of the microphone at different angles, the diaphragm is subjected to different forces, so the corresponding output is also different; this characteristic of changing the sensitivity of the microphone due to different angles of incident sound waves is called the directivity of the microphone.

[0003] Existing microphones generally do not have the function of active noise reduction, and need to be connected to an external device for noise reduction processing, which is inconvenient to use. Therefore, it is necessary to improve the current microphones. Utility Model Content

[0004] In view of this, the present invention aims to address the deficiencies in the prior art, and its main purpose is to provide an active noise reduction microphone circuit structure, which can effectively solve the problem that the existing microphones do not have the active noise reduction function.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] An active noise reduction microphone circuit structure is built into a microphone, and includes a preamplifier circuit, an ADC analog-to-digital conversion circuit and a DSP circuit. The preamplifier circuit is electrically connected to a microphone MIC, the ADC analog-to-digital conversion circuit is connected to the preamplifier circuit, and the DSP circuit is connected to the ADC analog-to-digital conversion circuit.

[0007] As a preferred solution, it further includes a USB interface, and the USB interface is connected to the DSP circuit.

[0008] As a preferred solution, an OVP circuit is further included, and the OVP circuit is connected to the USB interface.

[0009] As a preferred solution, it further includes an LDO circuit and a FLASH circuit, wherein the LDO circuit is connected to the DSP circuit, the ADC analog-to-digital conversion circuit and the FLASH circuit.

[0010] As a preferred solution, a DC-DC circuit is further included, and the DC-DC circuit is connected to the DSP circuit.

[0011] Compared with the prior art, the utility model has obvious advantages and beneficial effects. Specifically, it can be seen from the above technical solution that:

[0012] This product is built into the microphone. By coordinating the preamplifier circuit, ADC analog-to-digital conversion circuit and DSP circuit, the audio signal is picked up by the microphone MIC40, and then enters the preamplifier circuit for preamplification. Then, it enters the ADC analog-to-digital conversion circuit for analog-to-digital conversion into IIS digital signal. The IIS digital signal is output to the chip of the DSP circuit for noise reduction processing, thereby realizing active noise reduction function. There is no need to connect external devices, which is more convenient to use.

[0013] In order to more clearly illustrate the structural features and functions of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a circuit diagram of a preferred embodiment of the utility model;

[0015] Figure 2 It is a schematic diagram of a specific circuit structure of a preferred embodiment of the utility model.

[0016] Description of the accompanying drawings:

[0017] 10. Preamplifier circuit 20. ADC analog-to-digital conversion circuit

[0018] 30. DSP circuit 40. Pickup MIC

[0019] 51. USB interface 52. OVP circuit

[0020] 53. LDO circuit 54. FLASH circuit

[0021] 55. DC-DC circuit. DETAILED DESCRIPTION

[0022] Please refer to Figure 1 to Figure 2 As shown, it shows the specific structure of a preferred embodiment of the utility model, which is built into a microphone and includes a preamplifier circuit 10, an ADC analog-to-digital conversion circuit 20 and a DSP circuit 30.

[0023] The preamplifier circuit 10 is electrically connected to the microphone MIC40, the ADC analog-to-digital conversion circuit 20 is connected to the preamplifier circuit 10, and the DSP circuit 30 is connected to the ADC analog-to-digital conversion circuit 20. In this embodiment, the specific circuit structures of the preamplifier circuit 10, the ADC analog-to-digital conversion circuit 20 and the DSP circuit 30 are as follows: Figure 2 As shown, the DSP circuit 30 uses a chip U1 whose model is I94124.

[0024] It further includes a USB interface 51, an OVP circuit 52, an LDO circuit 53, a FLASH circuit 54 and a DC-DC circuit 55. The USB interface 51 is connected to the DSP circuit 30 so as to connect to an external PC via a USB cable to transmit signals; the OVP circuit 52 is connected to the USB interface 51 to prevent the USB interface 51 from being damaged by excessive voltage; the LDO circuit 53 is connected to the DSP circuit 30, the ADC analog-to-digital conversion circuit 20 and the FLASH circuit 54 to output a power supply of a certain voltage to the DSP circuit 30, the ADC analog-to-digital conversion circuit 20 and the FLASH circuit 54; the DC-DC circuit 55 is connected to the DSP circuit 30 to output two sets of power supplies of a certain voltage to the DSP circuit 30. The specific circuit structures of the OVP circuit 52, the LDO circuit 53, the FLASH circuit 54 and the DC-DC circuit 55 are as follows: Figure 2 shown.

[0025] The working principle of this embodiment is described in detail as follows:

[0026] When working, use a connecting line to connect the PC and the USB interface 51. During the working process, the audio signal is picked up by the microphone MIC40, and enters the operational amplifier U7A of the preamplifier circuit 10 through the capacitor C38 and the resistor R34 for preamplification. Then, it enters the ADC analog-to-digital conversion circuit 20 through the capacitor C43 and the capacitor C55 for analog-to-digital conversion into an IIS digital signal. The IIS digital signal is output to the chip U1 of the DSP circuit 30 for noise reduction processing. After the processing is completed, it is sent to the PC through the USB interface 51.

[0027] The design focus of the utility model is that the product is built into the microphone, and by coordinating the preamplifier circuit, the ADC analog-to-digital conversion circuit and the DSP circuit, the audio signal is picked up by the microphone MIC40, and then enters the preamplifier circuit for preamplification, and then enters the ADC analog-to-digital conversion circuit for analog-to-digital conversion to IIS digital signal, and the IIS digital signal is output to the chip of the DSP circuit for noise reduction processing, thereby realizing the active noise reduction function, without the need to connect external devices, and is more convenient to use.

[0028] The above description is only a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any slight modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. An active noise reduction microphone circuit structure, Features: It is built into the microphone, and includes a preamplifier circuit, an ADC analog-to-digital conversion circuit and a DSP circuit. The preamplifier circuit is electrically connected to the microphone MIC, the ADC analog-to-digital conversion circuit is connected to the preamplifier circuit, and the DSP circuit is connected to the ADC analog-to-digital conversion circuit; it further includes a USB interface, and the USB interface is connected to the DSP circuit.

2. The active noise reduction microphone circuit structure according to claim 1, Features: It further includes an OVP circuit, and the OVP circuit is connected to the USB interface.

3. The active noise reduction microphone circuit structure according to claim 1, Features: It further includes an LDO circuit and a FLASH circuit, wherein the LDO circuit is connected to the DSP circuit, the ADC analog-to-digital conversion circuit and the FLASH circuit.

4. The active noise reduction microphone circuit structure according to claim 1, Features: The device further comprises a DC-DC circuit, wherein the DC-DC circuit is connected to the DSP circuit.

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