A Bluetooth circuit board with a microphone having a built-in crystal oscillator

Abstract

The present invention discloses a Bluetooth circuit board with a microphone having a built-in crystal oscillator, comprising: an acoustic sensing unit for capturing sound and converting it into an electrical signal; a signal processing unit connected to the acoustic sensing unit for receiving the signal of the acoustic sensing unit and outputting it through a first output pin after processing; a crystal oscillator unit for providing a signal of a first set frequency band; a frequency division unit connected to the crystal oscillator unit for frequency division of the signal of the first set frequency band and outputting it through a second output pin. The above technical solution has the following advantages or beneficial effects: by using a crystal oscillator with a higher frequency to replace the 16MHz crystal oscillator, and utilizing the characteristic that the crystal oscillator with a higher frequency occupies a smaller area, the crystal oscillator is integrated into the microphone. After the microphone with a built-in crystal oscillator is integrated into the Bluetooth circuit board, the area of ​​the Bluetooth circuit board can be reduced, meeting the needs of integration and miniaturization of electronic products.

Description

Technical Field

[0001] The invention relates to the field of micro-electromechanical technology, and in particular to a Bluetooth circuit board with a microphone having a built-in crystal oscillator. Background Art

[0002] As a radio technology that supports short-distance communication between devices, Bluetooth has long been ubiquitous in our daily lives. Smart phones, smart bracelets, smart watches, smart desk lamps, smart headphones, smart rice cookers and other smart hardware devices actually use Bluetooth technology for transmission.

[0003] In the Bluetooth system, the circuit board mainly includes the main chip, microphone, crystal oscillator and antenna. The crystal oscillator provides the reference frequency signal in the Bluetooth circuit and is the core component that supports the wireless Bluetooth technology to achieve fast transmission. The most commonly used crystal oscillator in wireless Bluetooth is the 16MHZ crystal oscillator. With the convenience, miniaturization, and ultra-thin size of high-end smart products, more and more users will choose crystal oscillators with smaller package sizes. However, under the existing technical conditions, the size of the crystal oscillator cannot be further reduced, and the microphone and antenna cannot be integrated into the main chip. These have affected the further miniaturization of the Bluetooth circuit board and restricted the development trend of further portable, miniaturized, and integrated electronic products. Summary of the invention

[0004] In view of the limitations of the prior art, the present invention provides a Bluetooth circuit board with a microphone having a built-in crystal oscillator.

[0005] The above technical solution specifically includes:

[0006] A Bluetooth circuit board with a microphone having a built-in crystal oscillator, comprising:

[0007] An acoustic sensing unit for capturing sound and converting it into an electrical signal;

[0008] A signal processing unit connected to the acoustic sensing unit, configured to receive the signal from the acoustic sensing unit and output the signal through a first output pin after processing;

[0009] a crystal oscillator unit, used for providing a signal of a first set frequency band;

[0010] a frequency division unit connected to the crystal oscillator unit, dividing the frequency of the signal in the first set frequency band and outputting the signal through a second output pin;

[0011] A Bluetooth circuit board, including a microphone, a main chip and an antenna;

[0012] The main chip, the antenna and the microphone are arranged on the Bluetooth circuit board;

[0013] The first set frequency band is an integer multiple of 16 MHz, and the integer multiple is assumed to be N, and the value range of N is 2, 3, 4, ...

[0014] Preferably, in the above-mentioned Bluetooth circuit board with a microphone having a built-in crystal oscillator, the acoustic sensing unit includes a digital microphone or an analog microphone.

[0015] Preferably, in the above-mentioned Bluetooth circuit board with a microphone having a built-in crystal oscillator, the crystal oscillator unit includes a crystal oscillator, a first oscillation starting capacitor, and a second oscillation starting capacitor;

[0016] The first oscillation capacitor is connected between the first end of the crystal oscillator and the ground end;

[0017] The second oscillation capacitor is connected between the second end of the crystal oscillator and the ground end.

[0018] Preferably, in the above-mentioned Bluetooth circuit board with a microphone having a built-in crystal oscillator, the frequency division unit adopts an N frequency divider, where N=2, 3, 4, ...

[0019] Preferably, in the above-mentioned Bluetooth circuit board with a microphone having a built-in crystal oscillator, an inverter is connected between the frequency division unit and the first end of the crystal oscillator.

[0020] Preferably, in the above-mentioned Bluetooth circuit board with a microphone having a built-in crystal oscillator, the acoustic sensing unit includes an electret microphone or a micro-electromechanical system microphone.

[0021] Preferably, in the above-mentioned Bluetooth circuit board with a microphone having a built-in crystal oscillator, the signal processing unit, the crystal oscillator unit and the frequency division unit are integrated on a dedicated integrated circuit chip.

[0022] The above technical solution has the following advantages or beneficial effects: by using a higher frequency crystal oscillator instead of a 16MHz crystal oscillator, and taking advantage of the fact that a higher frequency crystal oscillator occupies a smaller area, the crystal oscillator is integrated into the microphone. After the microphone with a built-in crystal oscillator is integrated into the Bluetooth circuit board, the area of ​​the Bluetooth circuit board can be reduced, thereby meeting the needs of integration and miniaturization of electronic products. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention and its features, configurations and advantages will become more apparent by reading the detailed description of non-limiting embodiments with reference to the following drawings. It should be noted that the relevant components in the drawings are not drawn to scale, and the focus is on illustrating the subject matter of the present invention.

[0024] Figure 1 It is a circuit schematic diagram of a Bluetooth circuit board with a microphone having a built-in crystal oscillator in a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0026] like Figure 1 As shown, in a preferred embodiment of the present invention, a Bluetooth circuit board with a microphone having a built-in crystal oscillator comprises:

[0027] An acoustic sensing unit MIC, used to capture sound and convert it into an electrical signal;

[0028] The signal processing unit Amp is connected to the acoustic sensing unit MIC and is used to receive the signal of the acoustic sensing unit MIC and output it through a first output pin end OUT1 after processing;

[0029] a crystal oscillator unit, used for providing a signal of a first set frequency band;

[0030] A frequency dividing unit Divider is connected to the crystal oscillator unit, and divides the frequency of the signal of the first set frequency band and outputs the signal through a second output pin end OUT2.

[0031] The main purpose of the present invention is to divide the first set frequency band 16MHz provided by the crystal oscillator unit into integer multiples of 16MHz through a frequency dividing unit Divider, wherein the value range of the integer multiple N is 2, 3, 4, ..., and then output it through the second output pin end OUT2, so that the crystal oscillator X can be integrated into the microphone and then integrated into the Bluetooth circuit board, thereby reducing the area of ​​the circuit board and meeting different configurations.

[0032] In a preferred embodiment of the present invention, the acoustic sensing unit MIC includes a digital microphone or an analog microphone.

[0033] In a preferred embodiment of the present invention, the crystal oscillator unit includes a crystal oscillator X, a first oscillating capacitor C1, and a second oscillating capacitor C2;

[0034] The first oscillating capacitor C1 is connected between the first end of the crystal oscillator X and the ground end;

[0035] The second oscillating capacitor C2 is connected between the second end of the crystal oscillator X and the ground end.

[0036] The first oscillating capacitor C1 and the second oscillating capacitor C2 are used to make the crystal X oscillate.

[0037] In a preferred embodiment of the present invention, the first set frequency band is an integer multiple of 16 MHz, and the integer multiple N=2, that is, the first set frequency band is 32 MHz.

[0038] In a preferred embodiment of the present invention, the frequency dividing unit Divider adopts N frequency dividers, where N=2, 3, 4, ...

[0039] In a preferred embodiment of the present invention, an inverter INV is connected between the frequency dividing unit Divider and the first end of the crystal oscillator X.

[0040] The inverter INV is used to enable the crystal X to continuously oscillate and obtain a signal of a second frequency band, which is output through the second output pin OUT2. In a preferred embodiment of the present invention, the acoustic sensing unit MIC includes an electret microphone or a micro-electromechanical system microphone.

[0041] In a preferred embodiment of the present invention, the signal processing unit Amp is integrated with the crystal oscillator unit and the frequency dividing unit Divider on a dedicated integrated circuit chip, thereby effectively reducing the area of ​​the microphone and leaving more wiring space, conforming to the development trend of high density, miniaturization and integration of circuit boards.

[0042] A Bluetooth circuit board includes a microphone;

[0043] The microphone uses the microphone with a built-in crystal oscillator as described in the above embodiment.

[0044] In a preferred embodiment of the present invention, it also includes a main chip and an antenna;

[0045] The main chip, antenna and microphone are arranged on the Bluetooth circuit board, so that a highly integrated Bluetooth circuit board can be obtained, thereby reducing the area of ​​the Bluetooth circuit board and realizing a miniaturized and integrated Bluetooth circuit board.

[0046] It should be understood by those skilled in the art that they can implement various variations by combining the prior art and the above embodiments. Such variations do not affect the essential content of the present invention and are not described in detail herein.

[0047] The above describes the preferred embodiments of the present invention. It should be understood that the present invention is not limited to the above-mentioned specific embodiments, and the devices and structures that are not described in detail should be understood to be implemented in a common manner in the art; any technician familiar with the art can use the above-disclosed methods and technical contents to make many possible changes and modifications to the technical solutions of the present invention without departing from the scope of the technical solutions of the present invention, or modify them into equivalent embodiments of equivalent changes, which does not affect the essential content of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention are still within the scope of protection of the technical solutions of the present invention.

Claims

1. A Bluetooth circuit board with a microphone having a built-in crystal oscillator, characterized in that: include: A microphone, a main chip and an antenna; The main chip, the antenna and the microphone are arranged on the Bluetooth circuit board; The microphone comprises: An acoustic sensing unit for capturing sound and converting it into an electrical signal; A signal processing unit connected to the acoustic sensing unit, configured to receive the signal from the acoustic sensing unit and output the signal through a first output pin after processing; a crystal oscillator unit, used for providing a signal of a first set frequency band; A frequency division unit connected to the crystal oscillator unit for dividing the signal of the first set frequency band After frequency division, it is output through a second output pin; The first set frequency band is an integer multiple of 16 MHz, and the integer multiple is assumed to be N, and the value range of N is 2, 3, 4, ...; The signal processing unit, the crystal oscillator unit and the frequency division unit are integrated on a dedicated integrated circuit chip.

2. The Bluetooth circuit board with a microphone having a built-in crystal oscillator as claimed in claim 1, characterized in that: The acoustic sensing unit includes a digital microphone or an analog microphone.

3. The Bluetooth circuit board with a microphone having a built-in crystal oscillator as claimed in claim 1, characterized in that: The crystal oscillator unit includes a crystal oscillator, a first oscillation starting capacitor, and a second oscillation starting capacitor; The first starting capacitor is connected between the first end of the crystal oscillator and the ground end; The second oscillation capacitor is connected between the second end of the crystal oscillator and the ground end.

4. The Bluetooth circuit board with a microphone having a built-in crystal oscillator as claimed in claim 1, characterized in that: The frequency division unit adopts N frequency dividers, N=2, 3, 4, ...

5. The Bluetooth circuit board with a microphone having a built-in crystal oscillator as claimed in claim 3, characterized in that: An inverter is connected between the frequency division unit and the first end of the crystal oscillator.

6. The Bluetooth circuit board with a microphone having a built-in crystal oscillator as claimed in claim 1, characterized in that: The acoustic sensing unit includes an electret microphone or a micro-electromechanical system microphone.

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