Low quiescent current bone conduction type hearing aid circuit and control method

Abstract

The invention relates to a low quiescent current bone conduction type hearing aid circuit and a control method. The hearing aid circuit comprises a digital hearing aid module, a charging management module, a power amplification module, a battery and a bone vibrator. The digital hearing aid module is used for outputting a corresponding audio signal, the audio output end of the digital hearing aid module is connected with the audio input end of the power amplification module, and the audio output end of the power amplification module is connected with the bone vibrator so as to drive the bone vibrator to execute a corresponding vibration action based on the audio signal; the control signal output end of the digital hearing aid module is connected with the control signal input end of the power amplification module, and when it is judged that the battery is in the charging state according to the voltage signal, the digital hearing aid module controls the power amplification module to stop outputting the audio signal to the bone vibrator. The completeness of basic functions of the bone conduction hearing aid is guaranteed, active suppression of a high-power-consumption link is achieved, and the problems that an existing bone conduction hearing aid is frequently charged and poor in use continuity due to the fact that quiescent current is too large are solved.

Description

Technical Field

[0001] This application relates to the technical field of hearing aids, and in particular to a low quiescent current bone conduction hearing aid circuit and control method. Background Technology

[0002] Currently, bone conduction hearing aids are hearing aids that transmit sound signals directly to the inner ear through the skull via mechanical vibration. However, compared to traditional air conduction hearing aids, bone conduction hearing aids require sufficiently strong mechanical vibrations from a bone vibrator to achieve effective sound transmission. The driving process itself demands higher power, especially in low-to-mid-frequency speech enhancement scenarios, where the power amplifier circuit and bone vibrator load significantly increase system energy consumption. In existing technologies, bone conduction hearing aids typically use audio processing chips with integrated Bluetooth communication functions for signal processing and wireless transmission. While these chips can perform multiple functions such as audio acquisition, digital processing, and wireless connectivity, their quiescent current is generally high. For example, some Bluetooth chips can have a quiescent current of over ten milliamps in standby or low-load operation. In practical applications of hearing aids, since the device needs to be worn for extended periods and continuously in standby or operating states, high quiescent current directly leads to rapid battery depletion. However, due to limitations in hearing aid size and wearing comfort, the internal battery capacity of the device cannot be significantly increased. This means that existing bone conduction hearing aids often require frequent charging during actual use, sometimes even multiple times a day in everyday scenarios, which seriously affects the user experience and the device's continuous working capability. Traditional bone conduction hearing aids, especially those worn all day, have extremely stringent requirements for circuit power consumption. Current technologies often employ intermittent operation, reduced gain, or significant performance degradation to reduce power consumption, which can lead to discontinuous sound signals, lower volume, or poorer sound quality. While using current-mode structures and operating MOSFETs in the subthreshold region can also reduce power consumption, maintaining sufficient output drive capability and signal fidelity in this state remains a challenge. Therefore, there is an urgent need for a circuit solution that can operate stably with extremely low quiescent current without sacrificing the essential performance characteristics of bone conduction hearing aids. Summary of the Invention

[0003] To address the issues of high power consumption, short battery life, and frequent charging required in existing bone conduction hearing aids due to the use of high quiescent current chips, this application provides a low quiescent current bone conduction hearing aid circuit and control method.

[0004] A low quiescent current bone conduction hearing aid circuit, the low quiescent current bone conduction hearing aid circuit comprising a digital hearing aid module, a charging management module, a power amplification module, a battery, and a bone resonator; The power input terminal of the charging management module is connected to the charging power supply, and the power output terminal of the charging management module is connected to the battery to form a charging path for the battery. When the battery is not charging, it outputs power to supply electricity. The digital hearing aid module is used to perform digital speech processing on the collected sound signal to output a corresponding audio signal. The audio output terminal of the digital hearing aid module is connected to the audio input terminal of the power amplifier module, and the audio output terminal of the power amplifier module is connected to the bone vibrator to drive the bone vibrator to perform a corresponding vibration action based on the audio signal. The charging detection signal input terminal of the digital hearing aid module is used to detect the voltage signal on the charging input side in the charging path. The control signal output terminal of the digital hearing aid module is connected to the control signal input terminal of the power amplifier module. When the voltage signal indicates that the battery is in a charging state, the digital hearing aid module controls the power amplifier module to stop outputting the audio signal to the bone resonator.

[0005] By adopting the above technical solution, the power amplifier module is actively controlled by the digital hearing aid module to stop working during the charging state, which effectively avoids the continuous power consumption of the bone resonator and power amplifier in unnecessary states, thereby significantly reducing the static current of the whole device and extending the battery life.

[0006] Preferably, the charging management module includes a management chip U2, an interface terminal USB, a resistor R14, and an indicator LED1. The power input terminal of the interface terminal USB is connected to a charging power source, and the power output terminal of the interface terminal USB is connected to the power input terminal of the management chip U2. The power output terminal of the management chip U2 outputs power to supply power to the battery, thereby putting the battery in a charging state. The common node between the power input terminal of the interface terminal USB and the power source is connected to the anode terminal of the indicator LED1. The cathode terminal of the indicator LED1 is connected to the first end of the resistor R14, and the second end of the resistor R14 is connected to the indicator signal input terminal of the management chip U2.

[0007] By adopting the above technical solution and setting up a charging management module and a charging indicator structure, intuitive feedback on the battery charging status can be achieved, while ensuring the stability and safety of the battery charging process.

[0008] Preferably, the digital hearing aid module includes a signal acquisition unit and a digital hearing aid chip U1. The signal acquisition unit includes resistors R19 and R23. The common node between the power input terminal of the charging management module and the charging power supply is connected to the first terminal of resistor R19. The second terminal of resistor R19 is connected to the first terminal of resistor R23. The second terminal of resistor R23 is grounded. The common node between the second terminal of resistor R19 and the first terminal of resistor R23 is connected to the detection signal input terminal of the digital hearing aid chip U1.

[0009] By adopting the above technical solution and performing voltage divider detection on the charging input side, the digital hearing aid module can accurately identify the charging status, providing a reliable basis for subsequent low-power control.

[0010] Preferably, the digital hearing aid module further includes a power control unit, which includes a diode D1, a touch switch POWER, a resistor R9, and a resistor R10. The common node between the power output terminal of the charging management module and the battery is connected to the first terminal of the touch switch POWER. The second terminal of the touch switch POWER is connected to the first terminal of the resistor R9. The second terminal of the resistor R9 is connected to the first terminal of the resistor R10. The second terminal of the resistor R10 is grounded. The common node between the second terminal of the resistor R9 and the first terminal of the resistor R10 is connected to the switch signal input terminal of the digital hearing aid chip U1. The wake-up signal output terminal of the digital hearing aid chip U1 is connected to the anode of the diode D1. The common node between the second terminal of the touch switch POWER and the first terminal of the resistor R9 is connected to the cathode of the diode D1.

[0011] By adopting the above technical solution, a self-locking control structure composed of a touch switch and a diode is used to achieve stable power-on retention after the button is released, and to reduce standby power consumption without introducing an additional control chip.

[0012] Preferably, the power amplification module includes a voltage regulator chip U3 and a power amplifier chip U4. The control signal input terminal of the voltage regulator chip U3 is connected to the wake-up signal output terminal of the digital hearing aid chip U1, the power output terminal of the voltage regulator chip U3 is connected to the power input terminal of the power amplifier chip U4, the enable signal input terminal of the power amplifier chip U4 is connected to the enable signal output terminal of the digital hearing aid chip U1, and the drive signal output terminal of the power amplifier chip U4 is connected to the bone vibrator.

[0013] By adopting the above technical solution, the working states of the voltage regulator chip and the power amplifier chip are controlled separately by the digital hearing aid module, thereby realizing the enable and power supply shutdown of the power amplifier module, thus minimizing energy loss while ensuring shutdown reliability.

[0014] Preferably, the power output terminal of the voltage regulator chip U3 and the power input terminal of the power amplifier chip U4 are connected by an inductor L3, and a capacitor C11 is connected between the common node of the inductor L3 and the power output terminal of the voltage regulator chip U3 and ground.

[0015] By adopting the above technical solution, and introducing a filter structure composed of inductors and capacitors at the regulated output terminal, ripple and interference in the power amplifier power supply process are effectively suppressed, thereby improving the power supply stability of the power amplifier module.

[0016] Preferably, a filtering module is provided between the audio signal input terminal of the power amplifier chip U4 and the audio signal output terminal of the digital hearing aid chip U1. The filtering module includes a primary filtering unit and a secondary filtering unit connected in series.

[0017] By adopting the above technical solution, and by setting up a multi-stage filtering structure between the digital hearing aid module and the power amplifier module, the impact of high-frequency noise on the power amplifier input is reduced, thereby improving the stability and listening quality of bone conduction audio output.

[0018] Preferably, the audio signal output terminal of the digital hearing aid chip U1 includes a non-inverting output port and an inverting output port, the audio signal input terminal of the power amplifier chip U4 includes a non-inverting input port and an inverting input port, the first-stage filtering unit includes resistors R3 and R4 and capacitor C8, the second-stage filtering unit includes resistors R5 and R6 and capacitor C9, the non-inverting output port is connected to the first end of resistor R3, the second end of resistor R3 is connected to the first end of resistor R5, the second end of resistor R5 is connected to the non-inverting input port, and the inverting output port is connected to the first end of resistor R4. The second end of resistor R4 is connected to the first end of resistor R6, the second end of resistor R6 is connected to the inverting input port, the common node between the second end of resistor R3 and the first end of resistor R5 is connected to the first end of capacitor C8, the common node between the second end of resistor R4 and the first end of resistor R6 is connected to the second end of capacitor C8, the common node between the second end of resistor R5 and the non-inverting input port is connected to the first end of capacitor C9, and the common node between the second end of resistor R6 and the inverting input port is connected to the second end of capacitor C9.

[0019] By adopting the above technical solution, and by performing symmetrical two-stage RC filtering on the differential audio signal, high-frequency pulses and radio frequency interference are effectively suppressed, and the signal-to-noise ratio and speech clarity in the sensitive frequency band of the human ear are improved.

[0020] Preferably, the digital hearing aid module further includes resistor R7, resistor R22, and capacitor C7. The capacitor C7 is connected between the common node between the power output terminal of the charging management module and the battery and ground. The common node between the power output terminal of the charging management module and the battery is connected to the first end of resistor R22. The second end of resistor R22 is connected to the first end of resistor R7. The second end of resistor R7 is grounded. The common node between the second end of resistor R22 and the first end of resistor R7 is connected to the battery status signal input terminal of the digital hearing aid chip U1.

[0021] By adopting the above technical solution and detecting the battery voltage status in real time, the digital hearing aid module can take timely protective or shutdown measures when the power is low, thereby avoiding abnormal operation and extending battery life.

[0022] A control method for a low quiescent current bone conduction hearing aid circuit, comprising: using a low quiescent current bone conduction hearing aid circuit, the control method comprising: Obtain the voltage signal from the charging input side; The voltage signal is used to determine whether the battery is charging. If the battery is charging, the digital hearing aid module is controlled to enter the charging shutdown state, and the operating status parameters of the power amplifier module are obtained. The corresponding control strategy is determined based on the operating status parameters. Based on the control strategy, an enable / disable signal is sent to the power amplifier chip in the power amplifier module, and a timer is started. When the preset delay time in the control strategy is met, a power supply shutdown signal is sent to the voltage regulator in the power amplifier module to cut off the power supply output from the battery to the power amplifier chip, thereby stopping the output of audio signals to the bone resonator.

[0023] By adopting the above technical solution, the power amplifier module can be smoothly turned off by dynamically determining the turn-off sequence and delay strategy based on the charging state and the operating state parameters of the power amplifier module. This reduces the static current and avoids abnormal vibration and noise during the turn-off process.

[0024] In summary, this application includes at least one of the following beneficial technical effects: This application introduces a charging status sensing and power amplification control mechanism centered on a digital hearing aid module into the bone conduction hearing aid circuit, changing the existing technical mode of bone conduction hearing aids maintaining high power consumption during charging or non-operating states. Instead of simply relying on continuous power supply or manual shutdown to control power consumption, it establishes a stable charging path between the charging management module and the battery. The digital hearing aid module detects and determines the voltage signal on the charging input side, thus distinguishing between non-charging and charging states at the system level. When the battery is detected to be charging, the digital hearing aid module actively intervenes in the overall control logic, constraining the operating state of the power amplification module through its control signal output. This prevents the power amplification module from outputting audio drive signals to the bone resonator, thus avoiding unnecessary energy consumption by the bone resonator and its power amplification circuit. Since the power amplification module and bone resonator are the most energy-intensive functional units in a bone conduction hearing aid, this significantly reduces the static current of the entire device during charging or standby, effectively improving power utilization efficiency and single-use battery life without increasing battery capacity or relying on high-power wireless chips. This application, while ensuring the integrity of the basic functions of bone conduction hearing aids, achieves active suppression of high-power consumption circuits, solving the problem of frequent charging and poor continuity of use caused by excessive static current in existing bone conduction hearing aids. Attached Figure Description

[0025] Figure 1 This is a flowchart of a low quiescent current bone conduction hearing aid circuit according to one embodiment of this application.

[0026] Figure 2 This is a schematic diagram of the specific structure of a low static current bone conduction hearing aid circuit in one embodiment of this application. Detailed Implementation

[0027] The present application will be further described in detail below with reference to the accompanying drawings.

[0028] In one embodiment, such as Figure 1 As shown, this application discloses a low quiescent current bone conduction hearing aid circuit, which includes a digital hearing aid module, a charging management module, a power amplification module, a battery, and a bone resonator. The power input terminal of the charging management module is connected to the charging power supply, and the power output terminal of the charging management module is connected to the battery to form a charging path for the battery. When the battery is not charging, it outputs power to supply power. The digital hearing aid module is used to digitize the collected sound signals for speech processing to output corresponding audio signals. The audio output terminal of the digital hearing aid module is connected to the audio input terminal of the power amplifier module, and the audio output terminal of the power amplifier module is connected to the bone resonator to drive the bone resonator to perform corresponding vibration actions based on the audio signals. The charging detection signal input terminal of the digital hearing aid module is used to detect the voltage signal on the charging input side in the charging path. The control signal output terminal of the digital hearing aid module is connected to the control signal input terminal of the power amplifier module. When the voltage signal indicates that the battery is in a charging state, the digital hearing aid module controls the power amplifier module to stop outputting audio signals to the bone resonator.

[0029] In this embodiment, the low quiescent current bone conduction hearing aid circuit includes a digital hearing aid module, a charging management module, a power amplifier module, a battery, and a bone resonator. These components work in tandem in the power, signal, and control paths to achieve a balance between bone conduction hearing aid functionality and low-power control. The power input of the charging management module is connected to an external charging power source, and its power output is electrically connected to the battery. This creates a stable battery charging path when an external charging power source is connected, managing battery charging. When no charging power source is connected, the battery serves as the main power source for the entire device, providing the necessary power to the digital hearing aid module and the power amplifier module. The digital hearing aid module is connected to the battery and acquires the battery's output voltage in non-charging mode. Based on this voltage, it performs digital speech processing on the acquired sound signals. Its audio output is electrically connected to the audio input of the power amplifier module, allowing the digitally processed audio signal to be sent to the power amplifier module for further amplification. The audio output of the power amplifier module is connected to the bone resonator. When the power amplifier module is working, it amplifies the audio signal and drives the bone resonator to generate mechanical vibration. The bone resonator transmits the vibration signal to the inner ear through contact with the skull, thereby achieving the bone conduction hearing aid effect.

[0030] The digital hearing aid module also establishes an electrical connection with the charging path through its charging detection signal input terminal to detect the voltage signal on the charging input side, thereby determining whether an external charging power source is connected and whether the battery is charging. When the digital hearing aid module determines that the battery is charging based on the detected charging input voltage signal, it ceases normal hearing aid operation logic and instead sends a control signal to the power amplifier module through its control signal output terminal. This causes the power amplifier module to stop audio output, thus interrupting the drive of the bone conduction device. During this control process, the power amplifier module no longer amplifies the audio signal, and the bone conduction device is in a non-operating state, avoiding continuous energy consumption during charging or non-use phases. Through the above connection relationship and control logic, the digital hearing aid module not only undertakes voice processing functions in the entire device but also serves as the core control unit for power consumption management. After recognizing the charging status, it actively constrains the power amplifier module, causing the bone conduction device and its drive circuit to stop working in unnecessary states. This effectively reduces the overall static current of the device, improves power utilization efficiency, and extends the overall usage time of the bone conduction hearing aid.

[0031] It is worth noting that, in one specific embodiment, to address the problem of high power consumption and short battery life in existing bone conduction hearing aids due to high quiescent current, the low quiescent current bone conduction hearing aid circuit provided by this invention is optimized in terms of both signal processing path and power supply structure, with low power consumption as the overall design goal. The low quiescent current bone conduction hearing aid circuit includes a digital hearing aid module, a power amplifier module, a voltage regulator chip U3, a microphone, and a bone resonator. The digital hearing aid chip U1 in the digital hearing aid module is a low-current device, with a typical operating current of approximately 900μA under a 1.8V operating voltage, used for digital processing of speech signals and execution of control logic. The microphone uses a low-current silicon microphone structure, with an operating current of approximately 65μA under a 1.8V operating voltage, which can significantly reduce the power consumption of the front-end signal acquisition while meeting the requirements of speech acquisition sensitivity.

[0032] In the audio output path, the power amplifier chip U4 in the power amplifier module is a low quiescent current digital power amplifier. Its quiescent current is approximately 1300μA under a 3.0V operating voltage, providing the necessary driving capability for the bone conduction device with low quiescent power consumption. This ensures the bone conduction device obtains sufficient vibration amplitude and frequency response within the speech frequency range, thereby guaranteeing the bone conduction hearing aid effect. Regarding the power supply structure, the power amplifier module is powered by a voltage regulator chip U3. The voltage regulator chip U3 employs a low quiescent current, low dropout linear regulator structure, with a quiescent current as low as 1μA. While maintaining extremely low quiescent power consumption, it possesses excellent transient response capability, providing a stable output voltage even when the operating state of the power amplifier chip U4 changes, avoiding audio distortion or abnormal power consumption caused by power supply fluctuations.

[0033] Through the coordinated selection and structural configuration of the aforementioned low-power components, this embodiment ensures that the digital hearing aid module, microphone, power amplifier module, and voltage regulator chip all operate in a low quiescent current state within the entire device. This reduces the overall quiescent current of the low quiescent current bone conduction hearing aid circuit to approximately 2300μA under non-high-power output conditions, significantly lowering energy consumption compared to bone conduction hearing aids using high quiescent current Bluetooth chip solutions. Simultaneously, the low quiescent current bone conduction hearing aid circuit also incorporates a working indicator structure. This indicator can be configured to flash only during power-on and power-off processes, automatically turning off once the device enters normal operating mode, thus preventing additional power consumption from the indicator light remaining continuously lit.

[0034] Through the above embodiments, this invention, while ensuring the voltage swing and speech frequency response required for bone conduction device driving, achieves effective control of the overall static current, significantly improves power utilization efficiency, reduces the need for frequent charging during daily use, and thus effectively extends the continuous working time of the bone conduction hearing aid and enhances the user experience. Furthermore, as... Figure 2 As shown, the charging management module includes a management chip U2, an interface terminal USB, a resistor R14, and an indicator LED1. The power input terminal of the interface terminal USB is connected to the charging power supply, and the power output terminal of the interface terminal USB is connected to the power input terminal of the management chip U2. The power output terminal of the management chip U2 outputs power to supply power to the battery, thereby putting the battery in a charging state. The common node between the power input terminal of the interface terminal USB and the power supply is connected to the anode terminal of the indicator LED1. The cathode terminal of the indicator LED1 is connected to the first end of the resistor R14, and the second end of the resistor R14 is connected to the indicator signal input terminal of the management chip U2.

[0035] In this embodiment, the charging management module includes a management chip U2, an interface terminal USB, a resistor R14, and an indicator LED1. These components work collaboratively to support the battery charging path and indicate the charging status. The interface terminal USB serves as the access point for an external charging power source. Its power input is electrically connected to the external charging power source, allowing the externally supplied charging voltage to be introduced into the hearing aid circuitry. The power output of the interface terminal USB is connected to the power input of the management chip U2, guiding the external charging power to the management chip U2 via the interface terminal USB. The management chip U2 then manages and controls the charging process. The power output of the management chip U2 is connected to the battery. Upon detecting the access of an external charging power source, the management chip U2 outputs a controlled charging current and voltage to the battery according to a preset charging strategy, ensuring the battery is in a controlled charging state and guaranteeing the safety and stability of the battery charging process.

[0036] The common node between the USB power input terminal and the charging power supply is also connected to the anode of indicator LED1, allowing LED1 to directly sense the charging power supply's connection status. The cathode of LED1 is connected to the first terminal of resistor R14, and the second terminal of R14 is connected to the indicator signal input terminal of management chip U2. Resistor R14 serves as a current limiter and protector in this connection, limiting the current flowing through LED1 to prevent damage due to overcurrent. It also controls the brightness of the indicator light by adjusting its resistance value. The indicator signal input terminal of management chip U2 outputs corresponding indicator control signals based on its operating state, controlling the conduction state of LED1 through resistor R14. This allows LED1 to display a preset on or off state during charging, providing the user with intuitive feedback on whether the battery is charging.

[0037] The charging management module integrates the charging status with indicator light control logic while implementing battery charging functionality. This creates a unified functional system that integrates external power supply access, battery charging process, and charging status indication. This not only improves the reliability and safety of the charging process but also provides an intuitive display of the charging status without adding extra control circuitry, allowing users to easily monitor the device's charging status during actual use.

[0038] Furthermore, such as Figure 2 As shown, the digital hearing aid module includes a signal acquisition unit and a digital hearing aid chip U1. The signal acquisition unit includes resistors R19 and R23. The common node between the power input terminal of the charging management module and the charging power supply is connected to the first terminal of resistor R19. The second terminal of resistor R19 is connected to the first terminal of resistor R23. The second terminal of resistor R23 is grounded. The common node between the second terminal of resistor R19 and the first terminal of resistor R23 is connected to the detection signal input terminal of the digital hearing aid chip U1.

[0039] In this embodiment, the digital hearing aid module includes a signal acquisition unit and a digital hearing aid chip U1. The signal acquisition unit consists of resistors R19 and R23, used to sample and process the voltage signal on the charging input side. A charging input node is formed between the power input terminal of the charging management module and an external charging power supply. This node presents a corresponding charging input voltage when the external charging power supply is connected. The first end of resistor R19 is electrically connected to the charging input node, allowing the voltage signal on the charging input side to be introduced into the signal acquisition unit through resistor R19. The second end of resistor R19 is connected to the first end of resistor R23, forming an intermediate node for voltage sampling. This intermediate node is also connected to the detection signal input terminal of the digital hearing aid chip U1, so that the voltage signal after voltage division by resistors R19 and R23 is sent to the digital hearing aid chip U1 for detection and judgment. The second end of resistor R23 is grounded, enabling the signal acquisition unit to form a stable voltage divider structure. The resistance ratio of resistor R19 to resistor R23 is used to convert the higher voltage on the charging input side into a voltage level suitable for the range of the digital hearing aid chip U1's detection signal input terminal, so as to avoid damage to the chip or detection abnormalities caused by direct input of excessively high voltage. Resistors R19 and R23 together form a voltage divider sampling path for the charging input voltage signal, enabling the digital hearing aid chip U1 to acquire the voltage status information of the charging input side without directly participating in the charging power path. Based on the voltage divider received at its detection signal input terminal, the digital hearing aid chip U1 determines whether an external charging power supply is connected and whether the battery is charging, and switches its own operating logic accordingly. When a stable voltage signal is detected on the charging input side, the digital hearing aid chip U1 identifies that it is currently in a charging state, providing a reliable status judgment basis for subsequent execution of charging shutdown control or low-power control of the power amplification module. By integrating the charging status detection function with the audio processing core into the same digital hearing aid chip, this implementation avoids the introduction of additional comparators or control chips, effectively reducing circuit complexity and static power consumption while ensuring detection reliability, meeting the overall design requirements of bone conduction hearing aid circuits for miniaturization and low power consumption.

[0040] Furthermore, such as Figure 2As shown, the digital hearing aid module also includes a power control unit, which includes a diode D1, a touch switch POWER, resistors R9 and R10. The common node between the power output terminal of the charging management module and the battery is connected to the first terminal of the touch switch POWER. The second terminal of the touch switch POWER is connected to the first terminal of resistor R9. The second terminal of resistor R9 is connected to the first terminal of resistor R10. The second terminal of resistor R10 is grounded. The common node between the second terminal of resistor R9 and the first terminal of resistor R10 is connected to the switch signal input terminal of the digital hearing aid chip U1. The wake-up signal output terminal of the digital hearing aid chip U1 is connected to the anode of diode D1. The common node between the second terminal of the touch switch POWER and the first terminal of resistor R9 is connected to the cathode of diode D1.

[0041] In this embodiment, the digital hearing aid module also includes a power control unit for powering on, powering off, and maintaining the working state of the device. This power control unit consists of a diode D1, a touch switch POWER, resistors R9 and R10, and forms a coordinated control relationship with the charging management module and the digital hearing aid chip U1. A battery power supply node is formed between the power output terminal of the charging management module and the battery. This battery power supply node is electrically connected to the first terminal of the touch switch POWER, allowing the touch switch POWER to directly obtain the power voltage output from the battery. When the user presses the touch switch POWER, the first and second terminals of the touch switch POWER are connected, and the voltage of the battery power supply node is introduced to the first terminal of resistor R9 via the touch switch POWER. The second terminal of resistor R9 is connected to the first terminal of resistor R10, and the second terminal of resistor R10 is grounded, thereby forming a voltage divider node between resistors R9 and R10 for power-on detection. This voltage divider node is also connected to the switch signal input terminal of the digital hearing aid chip U1, enabling the digital hearing aid chip U1 to detect a valid power-on voltage signal when the button is triggered, and to execute the power-on process accordingly. After the digital hearing aid chip U1 completes the power-on determination and enters the working state, it outputs a stable wake-up control level through its wake-up signal output terminal. This wake-up signal output terminal is connected to the anode of diode D1, and the cathode of diode D1 is connected to the common node between the second terminal of the touch switch POWER and the first terminal of resistor R9. Through this connection, the wake-up signal output by the digital hearing aid chip U1 can be unidirectionally conducted to the power-on detection node via diode D1. After the touch switch POWER is released, this node continues to maintain an effective level, thus achieving the power self-holding function after the button is released. Diode D1 acts as a unidirectional isolation element in this structure, preventing the voltage of the battery-powered node or the button node from affecting the wake-up signal output terminal of the digital hearing aid chip U1 in reverse, ensuring the reliability and directionality of the control signal transmission. Resistor R9 in this power control unit limits the current flowing into the switch signal input terminal of the digital hearing aid chip U1, providing protection. It also, together with resistor R10, forms a stable voltage distribution relationship, giving the switch detection signal a clear level boundary and preventing false triggering due to voltage fluctuations or button bounce. Resistor R10 provides a stable reference potential to the power-on detection node through grounding, so that the node can reliably fall back to an invalid state when no button is pressed or the wake-up signal is maintained, thereby ensuring that the whole machine can be shut down normally; Without the need for an additional microcontroller or complex logic circuit, the power control unit achieves coordinated control functions such as touch button triggering, power-on determination of the digital hearing aid chip U1, and self-holding of the wake-up signal. This ensures that the device maintains simple operation while exhibiting stable power-on and power-off behavior, and effectively reduces ineffective power consumption in standby mode. It provides a reliable basic control condition for the realization of low static current bone conduction hearing aid circuits.

[0042] Furthermore, such as Figure 2 As shown, the power amplifier module includes a voltage regulator chip U3 and a power amplifier chip U4. The control signal input terminal of the voltage regulator chip U3 is connected to the wake-up signal output terminal of the digital hearing aid chip U1. The power output terminal of the voltage regulator chip U3 is connected to the power input terminal of the power amplifier chip U4. The enable signal input terminal of the power amplifier chip U4 is connected to the enable signal output terminal of the digital hearing aid chip U1. The drive signal output terminal of the power amplifier chip U4 is connected to the bone vibrator.

[0043] In this embodiment, the power amplification module includes a voltage regulator chip U3 and a power amplifier chip U4. Its overall function is to achieve controllable management of the power amplification unit's operating state while ensuring audio amplification performance, thus meeting the design requirements for low quiescent current operation. The power input terminal of the voltage regulator chip U3 is connected to the battery to obtain the original power supply voltage. After regulating the power supply voltage, the voltage regulator chip U3 provides a stable operating voltage to the power amplifier chip U4 through its power output terminal, enabling the power amplifier chip U4 to perform normal audio power amplification under the set voltage conditions. The audio signal input terminal of the power amplifier chip U4 is connected to the audio signal output terminal of the digital hearing aid chip U1, allowing the audio signal after digital speech processing by the digital hearing aid chip U1 to be sent to the power amplifier chip U4 for subsequent power amplification. The drive signal output terminal of the power amplifier chip U4 is connected to the bone conduction transducer, converting the amplified audio signal into a drive signal for the bone conduction transducer, thereby driving the bone conduction transducer to generate corresponding mechanical vibrations and realizing the bone conduction hearing aid function. The operating states of both the voltage regulator chip U3 and the power amplifier chip U4 are controlled by the digital hearing aid chip U1. Specifically, the control signal input terminal of the voltage regulator chip U3 is connected to the wake-up signal output terminal of the digital hearing aid chip U1. When the digital hearing aid chip U1 is in normal operating state, its wake-up signal output terminal outputs a valid control level, enabling the voltage regulator chip U3 to enter the operating state and provide a stable power supply voltage to the power amplifier chip U4. When the digital hearing aid chip U1 enters the power-off or charging-off state, the control level output by its wake-up signal output terminal changes, causing the voltage regulator chip U3 to stop voltage regulation output, thereby cutting off the power supply path of the power amplifier chip U4. At the same time, the enable signal input terminal of the power amplifier chip U4 is connected to the enable signal output terminal of the digital hearing aid chip U1. The digital hearing aid chip U1 controls the operating permission state of the power amplifier chip U4 through this enable signal output terminal. When it detects that audio output is not required, the digital hearing aid chip U1 can first disable the power amplifier chip U4, causing it to stop audio amplification and output. The power amplifier module employs a dual control structure managed by the digital hearing aid chip U1. At the logic level, the enable signal of the power amplifier chip U4 enables rapid shutdown of the audio amplification function; at the power level, the voltage regulator chip U3 controls the regulated output to completely cut off the power supply to the power amplifier chip U4. This dual control method ensures that the power amplifier chip U4 neither generates audio output nor continuously consumes power when not in use, significantly reducing the quiescent current of the power amplifier module in standby or charging states. Simultaneously, because the enable and power supply controls are collaboratively managed by the digital hearing aid chip U1 according to predetermined logic, the power amplifier chip U4 maintains a stable and controllable state during shutdown, avoiding abnormal output or interference caused by direct power cut-off, thus improving the overall reliability and user experience. Through this implementation, the power amplifier module meets the output requirements of bone conduction hearing aids while achieving refined management of high-power units, providing crucial support for the overall design goal of low quiescent current bone conduction hearing aid circuits.

[0044] Furthermore, such as Figure 2 As shown, the power output terminal of the voltage regulator chip U3 and the power input terminal of the power amplifier chip U4 are connected by an inductor L3. A capacitor C11 is connected between the common node of the inductor L3 and the power output terminal of the voltage regulator chip U3 and ground.

[0045] In this embodiment, an inductor L3 is connected in series between the power output terminal of the voltage regulator chip U3 and the power input terminal of the power amplifier chip U4 to filter and isolate the power output of the voltage regulator chip U3. The voltage regulator chip U3 converts the battery power voltage into a stable voltage suitable for the operation of the power amplifier chip U4. However, since the voltage regulator chip U3 may generate certain high-frequency ripple or transient interference signals during the adjustment process, directly connecting its output terminal to the power input terminal of the power amplifier chip U4 can easily cause these high-frequency components to be superimposed on the power supply terminal of the power amplifier chip U4, thereby affecting the operating stability and audio output quality of the power amplifier chip U4. By introducing an inductor L3 between the power output terminal of the voltage regulator chip U3 and the power input terminal of the power amplifier chip U4, and utilizing the inductor's characteristics of high impedance to high-frequency signals and low impedance to DC and low-frequency signals, the propagation of high-frequency ripple and interference components in the output voltage of the voltage regulator chip U3 to the power amplifier chip U4 can be effectively suppressed. Meanwhile, a capacitor C11 is connected in parallel with ground between the common node of inductor L3 and the power output terminal of voltage regulator chip U3. Capacitor C11 is used for bypass filtering and energy buffering of the voltage at this common node. When transient voltage fluctuations occur at the output terminal of voltage regulator chip U3 or when instantaneous current changes occur in power amplifier chip U4 during operation, capacitor C11 can quickly absorb or release charge, thereby smoothing the power node voltage, reducing power supply impedance, and providing transient current support for power amplifier chip U4. Inductor L3 and capacitor C11 work together to form a low-pass filter structure between the output terminal of voltage regulator chip U3 and the input terminal of power amplifier chip U4, ensuring good transmission characteristics of the power supply path within the DC and audio operating frequency range, while effectively attenuating high-frequency interference signals.

[0046] The power output from the voltage regulator chip U3 is filtered by inductor L3 and capacitor C11 before entering the power amplifier chip U4, providing a more stable and cleaner power supply environment for the power amplifier chip U4. This helps reduce noise and distortion introduced during power amplifier operation and improves the stability and consistency of the bone conduction drive signal. Simultaneously, this filtering structure can buffer power supply surges when the power amplifier chip U4 starts / stops or experiences load changes, reducing transient stress on the battery and voltage regulator chip U3 and improving the overall reliability of the device. In low quiescent current bone conduction hearing aid circuits, introducing this filtering structure into the power amplifier power supply path not only improves audio performance but also avoids abnormal power consumption caused by unstable power supply, providing a strong guarantee for the low power consumption and stable operation of the entire device.

[0047] Furthermore, such as Figure 2 As shown, the audio signal output terminal of the digital hearing aid chip U1 includes a non-inverting output port and an inverting output port; the audio signal input terminal of the power amplifier chip U4 includes a non-inverting input port and an inverting input port; the first-stage filtering unit includes resistors R3 and R4 and capacitor C8; the second-stage filtering unit includes resistors R5 and R6 and capacitor C9; the non-inverting output port is connected to the first end of resistor R3; the second end of resistor R3 is connected to the first end of resistor R5; the second end of resistor R5 is connected to the non-inverting input port; and the inverting output port is connected to the first end of resistor R4. The second end of resistor R4 is connected to the first end of resistor R6, the second end of resistor R6 is connected to the inverting input port, the common node between the second end of resistor R3 and the first end of resistor R5 is connected to the first end of capacitor C8, the common node between the second end of resistor R4 and the first end of resistor R6 is connected to the second end of capacitor C8, the common node between the second end of resistor R5 and the non-inverting input port is connected to the first end of capacitor C9, and the common node between the second end of resistor R6 and the inverting input port is connected to the second end of capacitor C9.

[0048] In this embodiment, the audio signal output terminal of the digital hearing aid chip U1 includes a non-inverting output port and an inverting output port. The two output signals are transmitted differentially to the non-inverting input port and the inverting input port of the power amplifier chip U4 to improve the anti-interference capability of the audio signal and reduce the impact of common-mode noise on sound quality. To effectively filter the differential audio signals, a first-stage filtering unit and a second-stage filtering unit are sequentially arranged between the digital hearing aid chip U1 and the power amplifier chip U4 along the signal transmission direction. Both filtering units adopt a symmetrical differential RC structure to ensure the consistency of amplitude and phase between the inverting and inverting audio channels.

[0049] The non-inverting output port of the digital hearing aid chip U1 is connected to the first end of resistor R3. The second end of resistor R3 is connected to the first end of resistor R5. The second end of resistor R5 is connected to the first end of resistor R2. The second end of resistor R2 is connected to the first end of capacitor C15. The second end of capacitor C15 is connected to the non-inverting input port of the power amplifier chip U4, thus forming a series signal path consisting of resistors R3, R5, R2, and capacitor C15 in the non-inverting audio channel. Simultaneously, the inverting output port of the digital hearing aid chip U1 is connected to the first end of resistor R4. The second end of resistor R4 is connected to the first end of resistor R6. The second end of resistor R6 is connected to the first end of resistor R1. The second end of resistor R1 is connected to the first end of capacitor C16. The second end of capacitor C16 is connected to the inverting input port of the power amplifier chip U4, thus forming a series signal path symmetrical to the non-inverting channel structure in the inverting audio channel.

[0050] The first-stage filtering unit is connected between the intermediate nodes of the in-phase and inverting channels via capacitor C8. Specifically, the common node between the second end of resistor R3 and the first end of resistor R5 is connected to the first end of capacitor C8, and the common node between the second end of resistor R4 and the first end of resistor R6 is connected to the second end of capacitor C8. Capacitor C8 in this position is used to bypass the high-frequency components in the differential signal, creating a discharge path for high-frequency noise between the in-phase and inverting channels, thereby suppressing high-frequency pulses and fast-edge interference that may exist in the output signal of the digital hearing aid chip U1. By placing capacitor C8 in the first-stage filtering position, high-frequency interference can be initially attenuated before the signal enters the subsequent stages, reducing the possibility of it propagating to the input of the power amplifier chip U4.

[0051] The secondary filtering unit is connected across the intermediate nodes closer to the power amplifier chip U4 via capacitor C9. Specifically, the common node between the second end of resistor R5 and the first end of resistor R2 is connected to the first end of capacitor C9, and the common node between the second end of resistor R6 and the first end of resistor R1 is connected to the second end of capacitor C9. Capacitor C9 further smooths the audio signal after the first-stage filtering, further attenuating any remaining high-frequency noise and radio frequency interference before it enters the power amplifier chip U4. Capacitors C15 and C16 are connected in series at the ends of the non-inverting and inverting channels, respectively. They not only isolate DC and transmit AC audio signals but also match the input impedance of the power amplifier chip U4, preventing mutual interference of DC bias voltages and ensuring that the input of the power amplifier chip U4 operates in a stable electrical state.

[0052] The audio signal output from the digital hearing aid chip U1 undergoes multi-stage spectrum shaping before entering the power amplifier chip U4. High-frequency impulse noise and radio frequency interference are attenuated step by step, while the effective signal within the speech band maintains good amplitude and phase consistency. This differential multi-stage filtering method not only helps improve the signal-to-noise ratio and speech clarity in the sensitive frequency bands of the human ear, but also reduces the risk of high-frequency interference amplification by the power amplifier chip U4, avoiding abnormal vibration or additional energy consumption of the bone conduction resonator due to noise drive. Thus, while ensuring sound quality stability, it also meets the design goal of low quiescent current for the entire device, achieving efficient and reliable operation of the bone conduction hearing aid circuit.

[0053] Furthermore, such as Figure 2 As shown, the digital hearing aid module also includes resistors R7 and R22 and capacitor C7. Capacitor C7 is connected between the common node between the power output terminal of the charging management module and the battery and ground. The common node between the power output terminal of the charging management module and the battery is connected to the first end of resistor R22. The second end of resistor R22 is connected to the first end of resistor R7. The second end of resistor R7 is grounded. The common node between the second end of resistor R22 and the first end of resistor R7 is connected to the battery status signal input terminal of the digital hearing aid chip U1.

[0054] In this embodiment, a battery power supply node is formed between the power output terminal of the charging management module and the battery. This node displays the real-time output voltage of the battery in the non-charging state, and reflects the voltage state under the combined action of the battery and the charging management module during the charging state. Capacitor C7 is connected in parallel between the battery power supply node and ground to decouple and filter the voltage of the battery power supply node, ensuring that the voltage of this node remains stable during load changes or charging / discharging switching, and preventing transient spikes, voltage fluctuations, or high-frequency interference from directly superimposing into the subsequent detection path.

[0055] The first end of resistor R22 is connected to the battery power supply node, allowing the voltage of the battery power supply node to be introduced into the battery status detection path through resistor R22. The second end of resistor R22 is connected to the first end of resistor R7, forming an intermediate node for voltage sampling. This intermediate node is also connected to the battery status signal input terminal of the digital hearing aid chip U1. The second end of resistor R7 is grounded, so that resistors R22 and R7 together form a stable voltage divider structure. By proportionally dividing the voltage of the battery power supply node, the battery voltage is converted into a voltage signal suitable for the detection range of the digital hearing aid chip U1, thereby avoiding detection errors or chip damage caused by direct input of battery voltage. By reasonably setting the resistance ratio of resistors R22 and R7, the digital hearing aid chip U1 can obtain corresponding detection levels in different battery voltage ranges, which can be used to distinguish different battery states such as normal operation, low battery, or need for shutdown protection.

[0056] A control method for a low quiescent current bone conduction hearing aid circuit, comprising: using a low quiescent current bone conduction hearing aid circuit, and the control method including: S10. Obtain the voltage signal from the charging input side; S20. Determine whether the battery is charging based on the voltage signal; S30. If the battery is charging, control the digital hearing aid module to enter the charging shutdown state, and obtain the working status parameters of the power amplifier module, and determine the corresponding control strategy based on the working status parameters. S40. Based on the control strategy, send an enable / disable signal to the power amplifier chip in the power amplifier module and start timing. When the preset delay time in the control strategy is met, send a power supply disable signal to the voltage regulator in the power amplifier module to cut off the power supply output from the battery to the power amplifier chip, thereby stopping the output of audio signals to the bone resonator.

[0057] In one specific implementation, the control method for the low quiescent current bone conduction hearing aid circuit is based on the aforementioned hardware structure of the digital hearing aid module, charging management module, power amplification module, battery, and bone resonator. Its control logic is uniformly executed by the digital hearing aid chip U1, used to manage the power amplification module in an orderly manner under different operating states. When an external charging power supply is connected via the USB interface terminal, the charging management module enters the working state, forming a stable charging voltage signal on the charging input side. This voltage signal is divided by a signal acquisition unit composed of resistors R19 and R23 and then sent to the detection signal input terminal of the digital hearing aid chip U1. The digital hearing aid chip U1 periodically or in real-time samples this detection signal and determines whether the battery is currently charging based on the sampled voltage level.

[0058] When the digital hearing aid chip U1 determines that the battery is not charging, it operates in normal hearing aid mode, digitizing the sound signal collected by the microphone and sending the processed audio signal through a filter module to the power amplifier module via its audio signal output. This allows the power amplifier chip U4 to drive the bone resonator normally under the stable power supply provided by the voltage regulator chip U3. When the digital hearing aid chip U1 determines that the battery has entered the charging state based on the voltage signal on the charging input side, it stops maintaining normal hearing aid output and enters the charging shutdown control process. It first acquires the current operating status parameters of the power amplifier module, including the enable status of the power amplifier chip U4, the power supply status of the voltage regulator chip U3, and whether the audio output is in an effective driving state.

[0059] After confirming that the power amplifier module is still operational, the digital hearing aid chip U1 outputs an enable / disable signal to the enable signal input terminal of the power amplifier chip U4 according to a preset control strategy. This disables the power amplifier chip U4, stopping power amplification and output of the audio signal, and the bone resonator stops its mechanical vibration. After the power amplifier chip U4 completes the disabling switch, the digital hearing aid chip U1 activates its internal timing mechanism and continuously monitors the system status during the timing process to ensure that the power amplifier chip U4 has stably entered the non-operating state. When the timing reaches the delay time set in the control strategy, the digital hearing aid chip U1 changes its output state through its wake-up signal output terminal, controlling the control signal input terminal of the voltage regulator chip U3. This causes the voltage regulator chip U3 to stop providing regulated power to the power amplifier chip U4, thereby cutting off the power supply path to the power amplifier module and shutting off the power supply to the power amplifier chip U4.

[0060] By employing the aforementioned control sequence of first enabling and then powering off, the power amplifier module can smoothly and controllably exit the operating state when entering the charging state, avoiding transient noise, abnormal vibration, or current surges caused by direct power cut-off. Simultaneously, after the power amplifier chip U4 completes its power cut-off, the power amplifier module no longer consumes battery energy, and the entire device retains only the low-power operating state of the digital hearing aid chip U1 and necessary detection circuits, thereby significantly reducing the quiescent current during charging and non-use phases. This control method works closely with the aforementioned hardware structure, ensuring low quiescent current control is reflected not only in component selection but also in the refined management of the operating timing of high-power modules. Ultimately, this allows the bone conduction hearing aid circuit to effectively improve battery life and user experience while maintaining functional reliability.

[0061] Specifically, the operating status parameters include at least the enable state of the power amplifier chip U4, the audio signal output state, and the power supply state of the voltage regulator chip U3. The enable state is used to characterize whether the power amplifier chip U4 is currently in a logic state that allows amplification. The audio signal output state is used to characterize whether the digital hearing aid chip U1 is still outputting a valid audio signal to the power amplifier module. The power supply state of the voltage regulator chip U3 is used to characterize whether the power amplifier module is still in a powered-on state.

[0062] After acquiring the aforementioned operating status parameters, the digital hearing aid chip U1 determines the corresponding control strategy based on different parameter combinations. When it detects that the power amplifier chip U4 is in an enabled state and has valid audio output, the digital hearing aid chip U1 prioritizes executing the enable-disable strategy. That is, it sends a disabling control signal to the power amplifier chip U4 through its enable signal output terminal, causing the power amplifier chip U4 to stop its audio power amplification function, thereby eliminating the driving source for the bone resonator. After the power amplifier chip U4 completes the disabling switch, the digital hearing aid chip U1 enters the delay control stage and determines the corresponding delay duration based on the current audio output status, battery voltage level, or preset system operating parameters, ensuring that the internal operating state of the power amplifier chip U4 is sufficiently stable.

[0063] When the digital hearing aid chip U1 detects that the power amplifier chip U4 is disabled and the delay condition is met, the digital hearing aid chip U1 further executes the power supply shutdown strategy. It controls the voltage regulator chip U3 to stop its regulated output via its wake-up signal output, thereby cutting off the power supply path to the power amplifier module and causing the power amplifier chip U4 to enter a completely power-off state. If the power amplifier chip U4 is detected to be disabled or the audio output has stopped prematurely when acquiring operating status parameters, the digital hearing aid chip U1 can shorten or skip the enable / disable phase and directly enter the corresponding power supply shutdown control strategy to reduce unnecessary waiting time and further reduce static power consumption.

[0064] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A low quiescent current bone conduction hearing aid circuit, characterized in that, The low quiescent current bone conduction hearing aid circuit includes a digital hearing aid module, a charging management module, a power amplifier module, a battery, and a bone resonator. The power input terminal of the charging management module is connected to the charging power supply, and the power output terminal of the charging management module is connected to the battery to form a charging path for the battery. When the battery is not charging, it outputs power to supply electricity. The digital hearing aid module is used to perform digital speech processing on the collected sound signal to output a corresponding audio signal. The audio output terminal of the digital hearing aid module is connected to the audio input terminal of the power amplifier module, and the audio output terminal of the power amplifier module is connected to the bone vibrator to drive the bone vibrator to perform a corresponding vibration action based on the audio signal. The charging detection signal input terminal of the digital hearing aid module is used to detect the voltage signal on the charging input side in the charging path. The control signal output terminal of the digital hearing aid module is connected to the control signal input terminal of the power amplifier module. When the voltage signal indicates that the battery is in a charging state, the digital hearing aid module controls the power amplifier module to stop outputting the audio signal to the bone resonator.

2. The low quiescent current bone conduction hearing aid circuit according to claim 1, characterized in that, The charging management module includes a management chip U2, an interface terminal USB, a resistor R14, and an indicator LED1. The power input terminal of the interface terminal USB is connected to the charging power supply, and the power output terminal of the interface terminal USB is connected to the power input terminal of the management chip U2. The power output terminal of the management chip U2 outputs power to supply power to the battery, thereby putting the battery in a charging state. The common node between the power input terminal of the interface terminal USB and the power supply is connected to the anode terminal of the indicator LED1. The cathode terminal of the indicator LED1 is connected to the first end of the resistor R14, and the second end of the resistor R14 is connected to the indicator signal input terminal of the management chip U2.

3. The low quiescent current bone conduction hearing aid circuit according to claim 1, characterized in that, The digital hearing aid module includes a signal acquisition unit and a digital hearing aid chip U1. The signal acquisition unit includes resistors R19 and R23. The common node between the power input terminal of the charging management module and the charging power supply is connected to the first terminal of resistor R19. The second terminal of resistor R19 is connected to the first terminal of resistor R23. The second terminal of resistor R23 is grounded. The common node between the second terminal of resistor R19 and the first terminal of resistor R23 is connected to the detection signal input terminal of the digital hearing aid chip U1.

4. A low quiescent current bone conduction hearing aid circuit according to claim 3, characterized in that, The digital hearing aid module also includes a power control unit, which includes a diode D1, a touch switch POWER, a resistor R9, and a resistor R10. The common node between the power output terminal of the charging management module and the battery is connected to the first terminal of the touch switch POWER. The second terminal of the touch switch POWER is connected to the first terminal of the resistor R9. The second terminal of the resistor R9 is connected to the first terminal of the resistor R10. The second terminal of the resistor R10 is grounded. The common node between the second terminal of the resistor R9 and the first terminal of the resistor R10 is connected to the switch signal input terminal of the digital hearing aid chip U1. The wake-up signal output terminal of the digital hearing aid chip U1 is connected to the anode of the diode D1. The common node between the second terminal of the touch switch POWER and the first terminal of the resistor R9 is connected to the cathode of the diode D1.

5. A low quiescent current bone conduction hearing aid circuit according to claim 4, characterized in that, The power amplification module includes a voltage regulator chip U3 and a power amplifier chip U4. The control signal input terminal of the voltage regulator chip U3 is connected to the wake-up signal output terminal of the digital hearing aid chip U1. The power output terminal of the voltage regulator chip U3 is connected to the power input terminal of the power amplifier chip U4. The enable signal input terminal of the power amplifier chip U4 is connected to the enable signal output terminal of the digital hearing aid chip U1. The drive signal output terminal of the power amplifier chip U4 is connected to the bone vibrator.

6. A low quiescent current bone conduction hearing aid circuit according to claim 5, characterized in that, The power output terminal of the voltage regulator chip U3 is connected to the power input terminal of the power amplifier chip U4 through an inductor L3, and a capacitor C11 is connected between the common node of the inductor L3 and the power output terminal of the voltage regulator chip U3 and ground.

7. A low quiescent current bone conduction hearing aid circuit according to claim 5, characterized in that, A filtering module is provided between the audio signal input terminal of the power amplifier chip U4 and the audio signal output terminal of the digital hearing aid chip U1. The filtering module includes a first-level filtering unit and a second-level filtering unit connected in series.

8. A low quiescent current bone conduction hearing aid circuit according to claim 7, characterized in that, The digital hearing aid chip U1 has an audio signal output terminal including a non-inverting output port and an inverting output port. The power amplifier chip U4 has an audio signal input terminal including a non-inverting input port and an inverting input port. The first-stage filtering unit includes resistors R3 and R4 and capacitor C8. The second-stage filtering unit includes resistors R5 and R6 and capacitor C9. The non-inverting output port is connected to the first end of resistor R3, the second end of resistor R3 is connected to the first end of resistor R5, the second end of resistor R5 is connected to the non-inverting input port, and the inverting output port is connected to the first end of resistor R4. The second end of resistor R4 is connected to the first end of resistor R6, the second end of resistor R6 is connected to the inverting input port, the common node between the second end of resistor R3 and the first end of resistor R5 is connected to the first end of capacitor C8, the common node between the second end of resistor R4 and the first end of resistor R6 is connected to the second end of capacitor C8, the common node between the second end of resistor R5 and the non-inverting input port is connected to the first end of capacitor C9, and the common node between the second end of resistor R6 and the inverting input port is connected to the second end of capacitor C9.

9. A low quiescent current bone conduction hearing aid circuit according to claim 3, characterized in that, The digital hearing aid module also includes resistors R7 and R22 and capacitor C7. Capacitor C7 is connected between the common node between the power output terminal of the charging management module and the battery and ground. The common node between the power output terminal of the charging management module and the battery is connected to the first end of resistor R22. The second end of resistor R22 is connected to the first end of resistor R7. The second end of resistor R7 is grounded. The common node between the second end of resistor R22 and the first end of resistor R7 is connected to the battery status signal input terminal of the digital hearing aid chip U1.

10. A control method for a low quiescent current bone conduction hearing aid circuit, using a low quiescent current bone conduction hearing aid circuit as described in any one of claims 1-9, the control method comprising: Obtain the voltage signal from the charging input side; The voltage signal is used to determine whether the battery is charging. If the battery is charging, the digital hearing aid module is controlled to enter the charging shutdown state, and the operating status parameters of the power amplifier module are obtained. The corresponding control strategy is determined based on the operating status parameters. Based on the control strategy, an enable / disable signal is sent to the power amplifier chip in the power amplifier module, and a timer is started. When the preset delay time in the control strategy is met, a power supply shutdown signal is sent to the voltage regulator in the power amplifier module to cut off the power supply output from the battery to the power amplifier chip, thereby stopping the output of audio signals to the bone resonator.

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