Dual-MIC multiplexing circuit and device with hearing aid and Bluetooth

Abstract

The utility model discloses a dual-MIC multiplexing circuit and device with hearing aid and Bluetooth. The multiplexing circuit comprises a Bluetooth wafer, a hearing aid wafer, two switches and two microphones. A first pin of the Bluetooth wafer is connected with a first microphone after being connected in parallel with a series branch of the first switch and a first pin of the hearing-aid wafer, and a second pin of the Bluetooth wafer is connected with a second microphone after being connected in parallel with a series branch of the second switch and a second pin of the hearing-aid wafer; the Bluetooth chip supplies power to the hearing aid chip and controls the hearing aid chip to work or not. The multiplexing device comprises the multiplexing circuit. According to the utility model, the Bluetooth chip and the hearing-aid chip can multiplex the dual IMC circuit under the condition that both the Bluetooth communication and the hearing-aid effect can use the acoustic algorithm, so that the device and PCBA layout space can be saved.

Description

Technical Field

[0001] This utility model relates to the field of headphone technology, and in particular to a dual-MIC multiplexing circuit and device with hearing aid and Bluetooth. Background Technology

[0002] Bluetooth earphones or TWS (True Wireless Stereo) earphones with hearing aid functionality use both a Bluetooth chip (BT chip) and an Assitive Listening Device (ALD chip). The ALD chip handles the hearing aid function, while the BT chip handles music and phone functions. Currently, some BT chips can implement hearing aid functions, but they are not as good as traditional ALD chips in terms of power consumption control and hearing aid algorithm optimization.

[0003] Bluetooth calling mode requires a microphone (MIC) to pick up the signal from the nearby caller and transmit it to the far call receiver. To improve the listening experience of the far call receiver, at least two microphones are usually required to apply auditory algorithms.

[0004] Hearing aid mode requires a microphone to pick up external sounds, amplify them, and then transmit them to the wearer via the player's SPK. In order to improve the wearer's listening experience, at least two microphones are usually required to apply auditory algorithms.

[0005] Existing Bluetooth headsets with hearing aid functionality use microphones in the following ways: 1. The Bluetooth chip connects to one microphone, and the hearing aid chip connects to two microphones. In this method, the Bluetooth chip cannot apply acoustic algorithms to improve call quality. 2. The Bluetooth chip connects to two microphones, and the hearing aid chip connects to one microphone. In this method, the hearing aid chip cannot apply acoustic algorithms to improve hearing aid performance. 3. The Bluetooth chip connects to two microphones, and the hearing aid chip connects to two microphones. This method requires four microphones within the headset device, occupying significant PCBA board space and requiring considerable structural assembly space.

[0006] If the headphones use only two microphones, the first pin MIC1 of the Bluetooth chip and the first pin MIC0 of the hearing aid chip are connected in parallel to the first microphone MIC1, and the second pin MIC2 of the Bluetooth chip and the second pin MIC1 of the hearing aid chip are connected in parallel to the second microphone MIC2. (See below) Figure 4In the case where the Bluetooth chip is directly connected to two microphones, after switching from Bluetooth mode (call or music) to hearing aid mode, the digital signal processing algorithm (DSP) in the Bluetooth chip does not immediately go to sleep, but instead goes to sleep at 30 seconds. During the delayed sleep process, the DSP releases the ADC resources in the mode-to-digital converter. This process generates an electrical pulse, which is transmitted to the hearing aid chip through the microphone path. The hearing aid chip amplifies the received pulse signal to generate a large pop noise. Utility Model Content

[0007] To address the aforementioned issues, this invention provides a dual-MIC multiplexing circuit and device with both hearing aid and Bluetooth capabilities. While ensuring that both Bluetooth calls and hearing aid performance can utilize acoustic algorithms, the Bluetooth chip and the hearing aid chip can reuse the dual-MIC circuit.

[0008] In a first aspect, this utility model provides a dual-MIC multiplexing circuit with hearing aid and Bluetooth capabilities, comprising:

[0009] Bluetooth chip, hearing aid chip, two switches and two microphones; the series branch of the first pin of the Bluetooth chip and the first switch is connected in parallel with the first pin of the hearing aid chip and then connected to the first microphone; the series branch of the second pin of the Bluetooth chip and the second switch is connected in parallel with the second pin of the hearing aid chip and then connected to the second microphone.

[0010] The Bluetooth chip powers the hearing aid chip and controls whether the hearing aid chip works.

[0011] Optionally, the two switches are analog switches.

[0012] Furthermore, the third pin of the Bluetooth chip is connected to the analog switch to control the opening and closing of the analog switch.

[0013] Furthermore, the enable pin of the Bluetooth chip is connected in series with the third switch and the power supply terminal of the hearing aid chip.

[0014] Preferably, the third switch is a MOS transistor.

[0015] Preferably, the fourth pin of the Bluetooth chip powers the first microphone; and / or, the fifth pin of the Bluetooth chip powers the second microphone.

[0016] Secondly, this utility model provides a dual-MIC multiplexing device with hearing aid and Bluetooth capabilities, comprising:

[0017] The device includes the multiplexing circuit.

[0018] Beneficial effects

[0019] 1) The Bluetooth chip and switch of this utility model are connected in series and then connected in parallel with the hearing aid chip. After being connected in parallel, they are connected to the microphone to form a branch. Two branches are set up, and only two microphones (MIC) are used. The Bluetooth chip and the hearing aid chip can reuse the dual MIC, ensuring that the dual MIC algorithm can be used in both Bluetooth mode and hearing aid mode, while ensuring Bluetooth call and hearing aid effect.

[0020] 2) Compared with existing technologies, it saves at least one microphone (MIC), thus saving costs and PCBA layout.

[0021] 3) Saves structural stacking space for microphones (MICs) inside the earphone shell, especially for Bluetooth earphones like TWS earphones, which are more sensitive to structural space.

[0022] 4) The two switches are controlled by the Bluetooth chip to avoid interference from the electrical pulse pop noise generated by the Bluetooth chip to the hearing aid chip when switching from Bluetooth mode to hearing aid mode.

[0023] 5) Power the hearing aid chip via the Bluetooth chip and control the switching of the hearing aid chip to avoid the hearing aid chip interfering with the microphone signal entering the Bluetooth chip when the hearing aid mode is switched to Bluetooth mode. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of a dual-MIC multiplexing circuit with hearing aid and Bluetooth provided by an embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of the microphone signal flow when the analog switch 1 provided by this utility model is closed and turned on;

[0026] Figure 3 This is a schematic diagram of the microphone signal flow when the analog switch 1 is open, as provided by this utility model;

[0027] Figure 4 This is a schematic diagram of a dual-MIC multiplexed circuit with hearing aid and Bluetooth provided by this utility model, which generates noise and popping noise. Detailed Implementation

[0028] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.

[0029] See Figure 1This utility model embodiment provides a schematic diagram of a dual-MIC multiplexing circuit with hearing aid and Bluetooth. The circuit includes: a Bluetooth chip, a hearing aid chip, two switches, and two microphones. The first terminal of the first switch is connected to the first pin MIC1 of the Bluetooth chip, and the second terminal of the first switch is connected in parallel with the first pin MIC0 of the hearing aid chip and then connected to the first microphone MIC1. The first terminal of the second switch is connected to the second pin MIC2 of the Bluetooth chip, and the second terminal of the second switch is connected in parallel with the second pin MIC1 of the hearing aid chip and then connected to the second microphone MIC2. Both switches are analog switches 1. The third pin PIO3 of the Bluetooth chip sends commands to control the opening and closing of the analog switches 1. The fourth pin PIO2 of the Bluetooth chip powers the first microphone MIC1, and the fifth pin PIO1 of the Bluetooth chip powers the second microphone MIC2.

[0030] The Bluetooth chip powers the hearing aid chip and controls its power on / off state. The Bluetooth chip's enable pin, DSP_EN, is connected to the input of a MOS transistor switch (Metal-Oxide-Semiconductor), and the output of the MOS transistor switch is connected to the power supply of the hearing aid chip.

[0031] In Bluetooth mode, the Bluetooth chip sends a command to the MOS transistor switch by providing a DSP_EN level signal to the enable pin. The MOS transistor switch then disconnects power to the hearing aid chip, causing the chip to power off. The microphone (MIC) signal flows as follows... Figure 2 The dashed line within the dashed box, as indicated by the arrow, represents the Bluetooth chip's third pin, PIO3, which sends a command to analog switch 1 to close and conduct. Microphone signals MIC1 and MIC2 then flow through analog switch 1 into the Bluetooth chip. Since the hearing aid chip is powered off, it will not interfere with the microphone signals MIC1 and MIC2 entering the Bluetooth chip.

[0032] In hearing aid mode, the Bluetooth chip enters a low-power sleep state, but still supplies power to the hearing aid chip. The Bluetooth chip sends a command to the MOS transistor switch by sending a level signal to the enable pin DSP_EN, and the MOS transistor switch closes to continue supplying power to the hearing aid chip. The third pin PIO3 of the Bluetooth chip sends a command to analog switch 1 to control analog switch 1 to open, and the microphone signals MIC1 and MIC2 flow as follows: Figure 3 The dashed lines within the dashed box indicate that the signals from microphones MIC1 and MIC2 directly enter the hearing aid chip. At this time, because the connection between the Bluetooth chip and microphones MIC1 and MIC2 is disconnected via analog switch 1, the electrical pulse signals generated by the Bluetooth chip will not cause popping noise interference to the microphone signals MIC1 and MIC2 entering the hearing aid chip.

[0033] Therefore, this embodiment can independently utilize two microphones (MICs) in both Bluetooth and hearing aid modes. This allows both the Bluetooth chip and the hearing aid chip to independently apply acoustic algorithms to improve call quality and hearing aid performance. From a physical standpoint, using only two microphones saves at least one microphone compared to existing Bluetooth headset circuits with hearing aid functionality, thus reducing costs and PCBA board space. Furthermore, it saves on the structural stacking space of the microphones within the earphone shell, which is particularly beneficial for TWS earphones, which are highly sensitive to structural space constraints.

[0034] Another embodiment of this utility model provides a dual-MIC multiplexing device with hearing aid and Bluetooth, which includes the aforementioned dual-MIC multiplexing circuit with hearing aid and Bluetooth. For detailed implementation, please refer to the circuit embodiment described above, which will not be repeated here.

[0035] The above description is the preferred embodiment of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this utility model, and these improvements and modifications are also considered to be within the protection scope of this utility model.

Claims

1. A dual-MIC multiplexing circuit with hearing aid and Bluetooth, comprising a Bluetooth chip and a hearing aid chip, characterized in that, It also includes two switches and two microphones; the series branch of the first pin of the Bluetooth chip and the first switch is connected in parallel with the first pin of the hearing aid chip and then connected to the first microphone; the series branch of the second pin of the Bluetooth chip and the second switch is connected in parallel with the second pin of the hearing aid chip and then connected to the second microphone. The Bluetooth chip powers the hearing aid chip and controls whether the hearing aid chip works.

2. The dual-MIC multiplexing circuit with hearing aid and Bluetooth as described in claim 1, characterized in that, The two switches are analog switches.

3. The dual-MIC multiplexing circuit with hearing aid and Bluetooth as described in claim 2, characterized in that, The third pin of the Bluetooth chip is connected to the analog switch and is used to control the opening and closing of the analog switch.

4. The dual-MIC multiplexing circuit with hearing aid and Bluetooth as described in claim 1, characterized in that, The enable pin of the Bluetooth chip is connected in series with the third switch and the power supply terminal of the hearing aid chip.

5. The dual-MIC multiplexing circuit with hearing aid and Bluetooth as described in claim 4, characterized in that, The third switch is a MOS transistor.

6. The dual-MIC multiplexing circuit with hearing aid and Bluetooth as described in claim 1, characterized in that, The fourth pin of the Bluetooth chip powers the first microphone; and / or the fifth pin of the Bluetooth chip powers the second microphone.

7. A dual-MIC multiplexing device with hearing aid and Bluetooth, characterized in that, The device includes the multiplexing circuit described in any one of claims 1-6.

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