System wake-up piezoelectric microphone module

Abstract

The application provides a system wake-up piezoelectric microphone module, which comprises: a wake-up piezoelectric microphone, which is used for generating a wake-up electric signal after receiving a sound wave; a wake-up chip, which is used for receiving the wake-up electric signal, performing threshold judgment on the wake-up electric signal, outputting a first control signal to a power supply voltage to control the power supply voltage to supply power to a pickup microphone and a processing chip when the wake-up electric signal is greater than the threshold, and outputting a second control signal to the power supply voltage to control the power supply voltage not to supply power to the pickup microphone and the processing chip when the wake-up electric signal is less than the threshold; the pickup microphone, which is used for picking up an external sound signal after being powered by the power supply voltage and converting the external sound signal into a picked-up electric signal; and the processing chip, which is used for receiving the picked-up electric signal, performing amplification processing on the pickup microphone, and outputting the amplified signal to a terminal device; and the resonant frequency of the wake-up chip is less than the resonant frequency of the pickup microphone. The application can effectively reduce system power consumption and improve system sensitivity.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of sound sensing, in particular to a system wake-up piezoelectric microphone module. BACKGROUND

[0002] In recent years, with the popularity of mobile devices and wearable devices, people interact with mobile devices and wearable devices more and more frequently. As a traditional human-to-human interaction method, sound has gradually shown its importance in human-computer interaction. For example, existing voice wake-up and voice recognition instructions can control the device without touching the electronic device, providing a better user experience. In order to obtain the user's sound signal in real time, the existing microphone needs to be in normal working state all the time to listen to the voice signal in real time, which increases the power consumption of the microphone.

[0003] In fact, the fundamental frequency of male voice is 85-180Hz, and the fundamental frequency of female voice is 165-255Hz. The actual frequency of human voice is the high harmonic of the fundamental frequency, and the area with the highest energy is not in the fundamental frequency. Human voice is mainly divided into vowels and consonants, and the frequency of vowels can reach 4000Hz, and the frequency of consonants can reach 6000Hz. In early telephone technology, the voice frequency band range is about 300-3400Hz.

[0004] The human perception frequency range of sound is 20Hz-20000Hz, and the loud human voice can reach 60dB. The microphone design on mobile devices and wearable devices is mainly to pick up human voice, including voice instructions, calls, and recordings. The current mainstream piezoelectric microphone resonant frequency is about 14KHz.

[0005] In order to ensure the flatness of the sensitivity response curve of the piezoelectric microphone, the resonant frequency of the piezoelectric microphone needs to be controlled above the working frequency, which makes the sensitivity of the piezoelectric microphone small in the working frequency range due to the distance from the resonant frequency. In actual application, an amplifier is needed to amplify the electrical signal. SUMMARY

[0006] In view of the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide a system wake-up piezoelectric microphone module to solve the problem of low sensitivity of the piezoelectric microphone module in the prior art.

[0007] To achieve the above object and other related objects, the present application provides a system wake-up piezoelectric microphone module, which comprises: a wake-up piezoelectric microphone, which is used to generate a wake-up electrical signal after receiving a sound wave; a wake-up chip, which is connected to the wake-up piezoelectric microphone, is used to receive the wake-up electrical signal, and performs threshold judgment on the wake-up electrical signal, if the wake-up electrical signal is greater than a threshold, outputs a first control signal to a power voltage to control the power voltage to supply power to a pickup microphone and a processing chip, if the wake-up electrical signal is less than the threshold, outputs a second control signal to the power voltage to control the power voltage not to supply power to the pickup microphone and the processing chip; the pickup microphone, which is connected to the wake-up chip, is used to pick up an external sound signal after being powered by the power voltage, and convert the external sound signal into a pickup electrical signal; the processing chip, which is connected to the pickup microphone, is used to receive the pickup electrical signal, and output the pickup electrical signal to a terminal device after amplification processing of the pickup microphone; and the resonance frequency of the wake-up chip is less than the resonance frequency of the pickup microphone.

[0008] Optionally, different from the conventional microphone working in a flat band, the wake-up piezoelectric microphone works in a resonance mode, and the resonance frequency is 2000 Hz-4000 Hz.

[0009] Optionally, the wake-up chip comprises a base body, a piezoelectric cantilever beam, and an electrode structure, one end of the piezoelectric cantilever beam is fixed on the base body, the other end is suspended, and the electrode structure is arranged on the surface of the piezoelectric cantilever beam.

[0010] Optionally, the piezoelectric cantilever beam has a plurality of hollow regions in the region of the electrode structure, so that the electrode structure is divided into a plurality of electrode unit regions arranged independently, and the electrode unit regions are connected in series by wires and work near the resonance frequency to enhance the wake-up electrical signal.

[0011] Optionally, the wake-up chip comprises a base body, a piezoelectric sheet, and an electrode structure, the base body is a ring-shaped base body, the periphery of the piezoelectric sheet is connected to the ring-shaped base body, the electrode structure is a ring-shaped electrode, and the ring-shaped electrode is arranged on the outer peripheral surface of the electrode structure.

[0012] Optionally, the ring-shaped base body is a circular ring-shaped base body, the ring-shaped electrode is a circular ring-shaped electrode, and the piezoelectric sheet is a circular piezoelectric sheet, and a weighted mass block is further arranged at the center of the circular piezoelectric sheet to reduce the resonance frequency of the circular piezoelectric sheet.

[0013] Optionally, the ring-shaped base body is a polygonal ring-shaped base body, the electrode structure is a polygonal ring-shaped electrode structure, and the piezoelectric sheet is a polygonal piezoelectric sheet.

[0014] Optionally, the circular piezoelectric sheet has a plurality of hollowed-out regions, so that the electrode structure is divided into a plurality of electrode unit regions arranged independently, and the electrode unit regions are connected in series by wires and work near the resonant frequency to enhance the wake-up electrical signal.

[0015] Optionally, the ring-shaped base is a rectangular ring base, the ring-shaped electrode is a rectangular ring electrode, and the piezoelectric sheet is a rectangular piezoelectric sheet, and the rectangular piezoelectric sheet has a plurality of hollowed-out regions in the area of the rectangular ring electrode, so that the electrode structure is divided into a plurality of electrode unit regions arranged independently, and the electrode unit regions are connected in series by wires to enhance the wake-up electrical signal.

[0016] Optionally, the middle region of the rectangular piezoelectric sheet has a plurality of hollowed-out regions, and the plurality of hollowed-out regions extend along the diagonal direction of the rectangular piezoelectric sheet.

[0017] Optionally, the plurality of electrode unit regions work near the resonant frequency under the action of sound waves, have the same vibration phase and vibration frequency.

[0018] Optionally, the wake-up chip includes a base, a piezoelectric sheet, and an electrode structure, the base is located on both sides of the piezoelectric sheet, the electrode structure is located on the two side edges of the piezoelectric sheet, the piezoelectric sheet and the electrode structure have a hollowed-out region at the junction, so that the piezoelectric sheet and the electrode structure region are connected by a bridge.

[0019] Optionally, the piezoelectric sheet also has a hollowed-out region extending from the junction of the piezoelectric sheet and the electrode structure to the middle of the piezoelectric sheet, so as to divide the piezoelectric sheet into a first part and a second part, and the first part and the second part are connected by a bridge.

[0020] Optionally, the wake-up chip includes a MOS tube, the wake-up piezoelectric microphone is connected to the gate of the MOS tube, and the threshold voltage of the MOS tube is lower than the voltage of the wake-up electrical signal generated after the wake-up piezoelectric microphone receives sound waves.

[0021] Optionally, it also includes a PCB circuit board and a shell, the wake-up piezoelectric microphone, the wake-up chip, the sound pickup microphone, and the processing chip are arranged on the PCB circuit board and realize the electrical connection of the wake-up piezoelectric microphone, the wake-up chip, the sound pickup microphone, and the processing chip, and the top of the shell is provided with a sound inlet hole.

[0022] Optionally, it also includes a PCB circuit board and a shell, the wake-up piezoelectric microphone, the wake-up chip, the sound pickup microphone, and the processing chip are arranged on the PCB circuit board and realize the electrical connection of the wake-up piezoelectric microphone, the wake-up chip, the sound pickup microphone, and the processing chip, and the PCB circuit board is provided with a first sound inlet hole corresponding to the wake-up piezoelectric microphone and a second sound inlet hole corresponding to the sound pickup microphone.

[0023] As described above, the system of the present application wakes up the piezoelectric microphone module, which has the following beneficial effects:

[0024] The present application proposes a zero-power system wake-up piezoelectric microphone module, which mainly utilizes the resonant state response of the wake-up piezoelectric microphone. Under the resonant state response, the wake-up piezoelectric microphone can output hundreds of millivolts of voltage under sound pressure. If in the case of human voice, the output voltage of the wake-up piezoelectric microphone can exceed the threshold voltage of the wake-up chip. Then the voltage supplies power to the pickup microphone and the integrated circuit chip. After power supply, the pickup microphone converts the picked-up sound signal into an electrical signal, which is input to the terminal device through the integrated circuit chip, thereby effectively reducing the system power consumption and improving the sensitivity of the system.

[0025] The wake-up piezoelectric microphone of the present application has only one resonant state in the designed wake-up working frequency range, and the vibration between the electrodes is in phase, thereby effectively increasing the output electrical signal of the wake-up piezoelectric microphone.

[0026] The present application proposes a system wake-up piezoelectric microphone module using a wake-up piezoelectric microphone with increased sensitivity at the resonant frequency. The resonant frequency of the wake-up microphone of the present application is designed to be 2000-4000 Hz, which can greatly increase the sensitivity at 2000-4000 Hz. Compared with the resonant frequency greater than 10KHz, the sensitivity at 100-2000Hz is also greatly improved. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 A structural block diagram of the system wake-up piezoelectric microphone module of the embodiment of the present application is shown.

[0028] Figures 2-4 A first wake-up piezoelectric microphone structure schematic diagram of the system wake-up piezoelectric microphone module of the embodiment of the present application is shown.

[0029] Figure 5 A second wake-up piezoelectric microphone structure schematic diagram of the system wake-up piezoelectric microphone module of the embodiment of the present application is shown.

[0030] Figure 6 A third wake-up piezoelectric microphone structure schematic diagram of the system wake-up piezoelectric microphone module of the embodiment of the present application is shown.

[0031] Figure 7 A fourth wake-up piezoelectric microphone structure schematic diagram of the system wake-up piezoelectric microphone module of the embodiment of the present application is shown.

[0032] Figure 8 A packaging structure schematic diagram of the system wake-up piezoelectric microphone module of the embodiment of the present application is shown.

[0033] Figure 9 Another packaging structure diagram of the system wake-up piezoelectric microphone module according to an embodiment of the present application.

[0034] Figure 10 A voltage frequency response curve of the system wake-up piezoelectric microphone module according to an embodiment of the present application under 1 Pa sound pressure.

[0035] Figure 11 A voltage frequency response curve of a mainstream microphone device under 1 Pa sound pressure.

[0036] Element number explanation

[0037] 10 wake-up piezoelectric microphone

[0038] 20 wake-up chip

[0039] 201 base body

[0040] 202 piezoelectric cantilever beam

[0041] 203 electrode structure

[0042] 204 lead wire

[0043] 205 hollowed-out area

[0044] 206 weighted mass

[0045] 207 piezoelectric sheet

[0046] 30 pickup microphone

[0047] 40 processing chip

[0048] 50 housing

[0049] 501 first sound inlet hole

[0050] 502 second sound inlet hole

[0051] 60 PCB circuit board

[0052] 601 sound inlet hole DETAILED DESCRIPTION

[0053] The present application is described herein with reference to specific embodiments thereof which are illustrated in the accompanying drawings. The advantages of the present application will be readily appreciated by those skilled in the art from the following description, with reference to the accompanying drawings, in which: the present application can be carried out by different embodiments and applications, and the details in the present specification can be modified or changed based on different views and applications without departing from the spirit of the present application.

[0054] As will be apparent, the embodiments of the application as discussed above can be modified in various ways without departing from the scope of the present application. For example, the embodiments of the application discussed above can be modified to include more or less steps, or to include different steps. Accordingly, the above description is not intended to limit the scope of the application, as defined by the appended claims.

[0055] For the purposes of this disclosure, spatially relative terms such as "beneath", "below", "lower", "under", "above", "upper" and the like can be used for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientations depicted in the figures. For example, if a device described herein is turned over in use, a relative prefiix term such as "below" can be interpreted to mean "above" or "upper". Likewise, for another example, a relative prefiix term such as "above" can be interpreted to mean "below" or "lower". Therefore, a relative prefiix term such as "below" should not necessarily be interpreted as being directed downward in use or operation, and likewise, a relative prefiix term such as "above" should not necessarily be interpreted as being directed upward in use or operation. The spatially relative terms in this disclosure are intended to encompass different orientations of the device in use or operation in addition to the orientations depicted in the figures. For example, if a device described herein is turned over in use, a relative prefiix term such as "below" can be interpreted to mean "above" or "upper", and, vice versa. Likewise, for another example, a relative prefiix term such as "above" can be interpreted to mean "below" or "lower", and, vice versa. Therefore, a relative prefiix term such as "below" should not necessarily be interpreted as being directed downward in use or operation, and likewise, a relative prefiix term such as "above" should not necessarily be interpreted as being directed upward in use or operation. The spatially relative terms in this disclosure are intended to encompass different orientations of the device in use or operation in addition to the orientations depicted in the figures. For example, if a device described herein is turned over in use, a relative prefiix term such as "below" can be interpreted to mean "above" or "upper", and, vice versa. Likewise, for another example, a relative prefiix term such as "above" can be interpreted to mean "below" or "lower", and, vice versa. Therefore, a relative prefiix term such as "below" should not necessarily be interpreted as being directed downward in use or operation, and likewise, a relative prefiix term such as "above" should not necessarily be interpreted as being directed upward in use or operation.

[0056] In the context of this application, a structure described as being "on" another structure can include embodiments where the structures are in direct contact and embodiments where one or more additional structures are interposed between the structures.

[0057] It is to be understood that the above-described arrangements are merely illustrative of the principles of this application and that numerous modifications can be devised by those skilled in the art without departing from the scope of the present application. It is intended that all such modification be included within the scope of the present application.

[0058] Example 1

[0059] As Figures 1-8 and Figures 10-11As shown, this embodiment provides a system wake-up piezoelectric microphone 10 module, which includes: a wake-up piezoelectric microphone 10, configured to generate a wake-up electrical signal after receiving a sound wave; a wake-up chip 20, connected to the wake-up piezoelectric microphone 10, configured to receive the wake-up electrical signal and perform a threshold judgment on the wake-up electrical signal. If the wake-up electrical signal is greater than the threshold, a first control signal is output to the power supply voltage to control the power supply voltage to supply power to the sound pickup microphone 30 and the processing chip 40; if the wake-up electrical signal is less than the threshold, a second control signal is output to the power supply voltage to control the power supply voltage not to supply power to the sound pickup microphone 30 and the processing chip 40; the sound pickup microphone 30 is connected to the wake-up chip 20, configured to pick up external sound signals after being supplied by the power supply voltage, and convert the external sound signals into picked-up electrical signals; the processing chip 40 is connected to the sound pickup microphone 30, configured to receive the picked-up electrical signals, amplify the sound pickup microphone 30, and output them to the terminal device; the resonant frequency of the wake-up chip 20 is lower than the resonant frequency of the sound pickup microphone 30.

[0060] In this embodiment, the resonant frequency of the wake-up piezoelectric microphone 10 is 2000Hz to 4000Hz. Based on the fact that the primary frequency of human voice is between 300Hz and 3400Hz, the present invention proposes a wake-up piezoelectric microphone 10 that utilizes the resonant frequency to increase sensitivity. The resonant frequency of the wake-up piezoelectric microphone 10 is 2000Hz to 4000Hz, thereby significantly increasing the sensitivity at 2000-4000Hz. Compared to the resonant frequency of conventional piezoelectric microphones greater than 10kHz, the wake-up piezoelectric microphone 10 of the present invention also has a significantly improved sensitivity at frequencies between 100Hz and 2000Hz, thereby further enhancing the wake-up piezoelectric microphone 10's sensitivity to human voices.

[0061] In one embodiment, if Figures 2-4 As shown, Figure 2 It is a schematic diagram of the three-dimensional structure of the wake-up chip 20 in one embodiment of the present invention. Figure 3 Display as Figure 2 A schematic diagram of the structure of the wake-up chip 20 from above, Figure 4 Display as Figure 2 The side view of the wake-up chip 20 is a schematic diagram of the structure of the wake-up chip 20, which includes a substrate 201, a piezoelectric cantilever beam 202, and an electrode structure 203. One end of the piezoelectric cantilever beam 202 is fixed to the substrate 201, and the other end is suspended in the air and can vibrate freely. The electrode structure 203 is provided on the surface of the piezoelectric cantilever beam 202. In this embodiment, the electrode structure 203 is provided on the surface of one end of the piezoelectric cantilever beam 202 close to the substrate 201. This piezoelectric cantilever beam 202 structure can effectively reduce the resonant frequency of the wake-up chip 20.

[0062] As shown in Figure 3 , the piezoelectric cantilever beam 202 has a plurality of hollowed-out areas 205 in the area of the electrode structure 203, so that the electrode structure 203 is divided into a plurality of electrode unit areas arranged independently, and the electrode unit areas are connected in series through the wires 204 to enhance the wake-up electrical signal. In this embodiment, the plurality of electrode unit areas have the same vibration phase and vibration frequency under the action of the sound wave.

[0063] In another embodiment, as shown in Figure 5 , the wake-up chip 20 includes a base body 201, a piezoelectric sheet 207, and an electrode structure 203, the base body 201 is a ring-shaped base body, the piezoelectric sheet 207 is connected to the ring-shaped base body at the periphery, and the electrode structure 203 is a ring-shaped electrode, which is arranged on the outer peripheral surface of the electrode structure 203.

[0064] Specifically, as shown in Figure 5 , the ring-shaped base body is a circular ring-shaped base body, the ring-shaped electrode is a circular ring-shaped electrode, and the piezoelectric sheet 207 is a circular piezoelectric sheet, and a weight block 206 is further arranged at the center of the circular piezoelectric sheet to reduce the resonant frequency of the circular piezoelectric sheet. The circular piezoelectric sheet has a plurality of hollowed-out areas 205, so that the electrode structure 203 is divided into a plurality of electrode unit areas arranged independently, and the electrode unit areas are connected in series through the wires 204 to enhance the wake-up electrical signal, and the hollowed-out areas 205 can also effectively reduce the resonant frequency of the rectangular piezoelectric sheet. In this embodiment, the plurality of electrode unit areas have the same vibration phase and vibration frequency under the action of the sound wave.

[0065] In one embodiment, the ring-shaped base body is a polygonal ring-shaped base body, the electrode structure is a polygonal ring-shaped electrode structure, and the piezoelectric sheet is a polygonal piezoelectric sheet. The polygonal ring-shaped includes a triangular ring, a quadrilateral ring, a pentagonal ring, a hexagonal ring, an octagonal ring, or other polygonal ring structures, and the polygonal includes a triangle, a quadrilateral, a pentagon, a hexagon, an octagon, or other polygonal structures. For example, as shown in Figure 6As shown, the annular base is a rectangular annular base, the annular electrode is a rectangular annular electrode, the piezoelectric sheet 207 is a rectangular piezoelectric sheet, the rectangular piezoelectric sheet has a plurality of hollow areas 205 in the rectangular annular electrode area, so that the electrode structure 203 is divided into a plurality of electrode unit areas arranged independently, and the electrode unit areas are connected in series through the wires 204 to enhance the wake-up electric signal. The hollow areas 205 can also effectively reduce the resonant frequency of the rectangular piezoelectric sheet. In this embodiment, the plurality of electrode unit areas have the same vibration phase and vibration frequency under the action of sound waves. The middle area of the rectangular piezoelectric sheet has a plurality of hollow areas 205, and the plurality of hollow areas 205 extend along the diagonal direction of the rectangular piezoelectric sheet, so as to reduce the resonant frequency of the rectangular piezoelectric sheet and improve the induction efficiency of the rectangular piezoelectric sheet to sound waves.

[0066] In yet another embodiment, as shown in Figure 7 As shown, the wake-up chip 20 includes a base 201, a piezoelectric sheet 207, and an electrode structure 203. The base 201 is located on both sides of the piezoelectric sheet 207. The electrode structure 203 is located on the two side edges of the piezoelectric sheet 207. The piezoelectric sheet 207 has a hollow area 205 at the junction with the electrode structure 203, so that the piezoelectric sheet 207 and the electrode structure 203 area are connected by a bridge. The piezoelectric sheet 207 also has a hollow area 205 extending from the junction of the piezoelectric sheet 207 and the electrode structure 203 to the middle of the piezoelectric sheet 207, so as to divide the piezoelectric sheet 207 into a first part and a second part, and the first part and the second part are connected by a bridge, so as to reduce the resonant frequency of the piezoelectric sheet 207 and improve the induction efficiency of the piezoelectric sheet 207 to sound waves.

[0067] In this embodiment, the wake-up chip 20 includes a MOS tube, and the wake-up piezoelectric microphone 10 is connected to the gate of the MOS tube. The threshold voltage of the MOS tube is lower than the wake-up electric signal voltage generated after the wake-up piezoelectric microphone 10 receives sound waves. For example, under the response of the resonant state, the wake-up piezoelectric microphone 10 can output a voltage of several hundred millivolts under a sound pressure of 1 Pa. If in the case of human voice, the output voltage is about 5 millivolts. Through the series connection of the electrodes, the output voltage can reach several tens of millivolts. At the same time, the threshold voltage of the MOS tube can be several tens of millivolts. Therefore, when the human voice wakes up, the output voltage of the wake-up piezoelectric microphone 10 can exceed the threshold voltage and turn on the MOS tube. After the MOS tube is turned on, the voltage supplies power to the pickup microphone 30 and the integrated circuit chip.

[0068] As shown in Figure 8As shown, the system wake-up piezoelectric microphone 10 module also includes a PCB circuit board and a shell 50. The wake-up piezoelectric microphone 10, the wake-up chip 20, the pickup microphone 30 and the processing chip 40 are arranged on the PCB circuit board and realize the electrical connection of the wake-up piezoelectric microphone 10, the wake-up chip 20, the pickup microphone 30 and the processing chip 40. A sound inlet hole 601 is provided on the top of the shell 50.

[0069] like Figure 10 and Figure 11 As shown, Figure 11 The voltage frequency response curve of the mainstream microphone device with a resonance frequency of around 14KHz under a sound pressure of 1Pa is shown. Figure 11 As shown, the voltage frequency response of this mainstream microphone device is around 1 millivolt in the operating frequency range (100 Hz to 10 kHz). Figure 10 The figure shows the voltage-frequency response curve of the wake-up piezoelectric microphone 10 of the present invention. The resonant frequency is around 2000 Hz. Compared with mainstream microphones, the voltage low-frequency response of the wake-up piezoelectric microphone 10 of the present invention can be increased by about ten times. Near the resonant state, the output voltage can be increased by hundreds of times. The increased output voltage of the wake-up piezoelectric microphone 10 of the present invention near the resonant state can exceed the threshold voltage of the wake-up chip 20, thereby turning on the pickup microphone 30 and the processing chip 40.

[0070] Example 2

[0071] like Figures 1-7 、 Figures 9-11 As shown, this embodiment provides a system wake-up piezoelectric microphone 10 module. The structure of the system wake-up piezoelectric microphone 10 module is as shown in Example 1. The difference from Example 1 is that, Figure 9 As shown, the system wake-up piezoelectric microphone 10 module includes a PCB circuit board and a shell 50. The wake-up piezoelectric microphone 10, the wake-up chip 20, the pickup microphone 30 and the processing chip 40 are arranged on the PCB circuit board and realize the electrical connection of the wake-up piezoelectric microphone 10, the wake-up chip 20, the pickup microphone 30 and the processing chip 40. The PCB circuit board is provided with a first sound input hole 501 corresponding to the wake-up piezoelectric microphone 10 and a second sound input hole 502 corresponding to the pickup microphone 30.

[0072] As described above, the system of the present invention wakes up the piezoelectric microphone 10 module, which has the following beneficial effects:

[0073] The application provides a zero-power system wake-up piezoelectric microphone 10 module, which mainly utilizes the resonant state response of the wake-up piezoelectric microphone 10, and under the resonant state response, the wake-up piezoelectric microphone 10 can output hundreds of millivolts of voltage under sound pressure; if under the condition of human voice, the output voltage of the wake-up piezoelectric microphone 10 can exceed the threshold voltage of the wake-up chip 20, then the voltage supplies power to the pickup microphone 30 and the integrated circuit chip, after the power supply, the pickup microphone 30 converts the picked sound signal into an electric signal, which is input to a terminal device through the integrated circuit chip, thereby effectively reducing the system power consumption and improving the sensitivity of the system.

[0074] The wake-up piezoelectric microphone 10 of the application has only one resonant state in the designed wake-up working frequency range, and the vibration between the electrodes is in phase, thereby effectively increasing the output electric signal of the wake-up piezoelectric microphone 10.

[0075] The application provides a system wake-up piezoelectric microphone 10 module, which utilizes the wake-up piezoelectric microphone 10 with increased sensitivity at the resonant frequency. The resonant frequency of the wake-up microphone of the application is designed to be 2000-4000 Hz, which can greatly increase the sensitivity at 2000-4000 Hz, and compared with the resonant frequency greater than 10 KHz, the sensitivity at 100-2000 Hz is also greatly improved.

[0076] Therefore, the application effectively overcomes the various shortcomings in the prior art and has high industrial utilization value.

[0077] The above examples only exemplarily illustrate the principles and effects of the application, and are not used to limit the application. Any person skilled in the art can modify or change the above examples without departing from the spirit and scope of the application. Therefore, all equivalent modifications or changes completed by those skilled in the art without departing from the spirit and technical thought disclosed by the application should be covered by the claims of the application.

Claims

1. A system wakeup piezoelectric microphone module, characterized in that, The system wake-up piezoelectric microphone module includes: Wake-up piezoelectric microphone, used to generate a wake-up electrical signal after receiving sound waves; a wake-up chip, connected to the wake-up piezoelectric microphone, configured to receive the wake-up electrical signal and perform a threshold judgment on the wake-up electrical signal; if the wake-up electrical signal is greater than the threshold, output a first control signal to the power supply voltage to control the power supply voltage to supply power to the pickup microphone and the processing chip; if the wake-up electrical signal is less than the threshold, output a second control signal to the power supply voltage to control the power supply voltage not to supply power to the pickup microphone and the processing chip; A pickup microphone, connected to the wake-up chip, is used to pick up external sound signals after being powered by a power supply voltage, and convert the external sound signals into pickup electrical signals; a processing chip connected to the sound pickup microphone, configured to receive the picked-up electrical signal, amplify the sound pickup microphone, and output the amplified signal to the terminal device; The resonant frequency of the wake-up chip is lower than the resonant frequency of the pickup microphone; The wake-up piezoelectric microphone operates in a resonant mode, and its resonant frequency is 2000Hz to 4000Hz; The wake-up chip includes a substrate, a piezoelectric cantilever thin film structure and an electrode structure, one end of the piezoelectric cantilever is fixed on the substrate, and the other end is suspended in the air, and the electrode structure is arranged on the surface of the piezoelectric cantilever; The piezoelectric cantilever beam has a plurality of hollow areas in the region of the electrode structure, so that the electrode structure is divided into a plurality of independently arranged electrode unit areas, and the electrode unit areas are connected in series through wires to enhance the wake-up electrical signal. 2.The system wake-up piezoelectric microphone module of claim 1, wherein: The wake-up chip includes a substrate, a piezoelectric sheet and an electrode structure. The substrate is an annular substrate. The periphery of the piezoelectric sheet is connected to the annular substrate. The electrode structure is an annular electrode. The annular electrode is arranged on the outer peripheral surface of the electrode structure. 3.The system wake-up piezoelectric microphone module of claim 2, wherein: The annular base is a polygonal annular base, the electrode structure is a polygonal annular electrode structure, and the piezoelectric sheet is a polygonal piezoelectric sheet. 4.The system wake-up piezoelectric microphone module of claim 2, wherein: The annular base is a circular base, the annular electrode is a circular electrode, the piezoelectric piece is a circular piezoelectric piece, and a weighted mass block is further provided at the center of the circular piezoelectric piece to reduce the resonant frequency of the circular piezoelectric piece.

5. The system wake-up piezoelectric microphone module of claim 4, wherein: The circular piezoelectric piece has multiple hollow areas, which divides the electrode structure into multiple independently arranged electrode unit areas, and the electrode unit areas are connected in series through wires and operate at a resonant frequency to enhance the wake-up electrical signal.

6. The system wake-up piezoelectric microphone module of claim 3, wherein: The annular base is a rectangular ring base, the annular electrode is a rectangular ring electrode, the piezoelectric sheet is a rectangular piezoelectric sheet, and the rectangular piezoelectric sheet has multiple hollow areas in the rectangular ring electrode area, so that the electrode structure is divided into multiple independently arranged electrode unit areas, and the electrode unit areas are connected in series through wires and operate at a resonant frequency to enhance the wake-up electrical signal.

7. The system wake-up piezoelectric microphone module of claim 6, wherein: The middle area of ​​the rectangular piezoelectric sheet has a plurality of hollow areas, and the plurality of hollow areas extend along the diagonal direction of the rectangular piezoelectric sheet.

8. The system wake-up piezoelectric microphone module of claim 1, 5, or 6, wherein: The plurality of electrode unit areas operate at a resonant frequency under the action of sound waves and have the same vibration phase and vibration frequency.

9. The system wake-up piezoelectric microphone module of claim 1, wherein: The wake-up chip comprises a base, a piezoelectric sheet and an electrode structure, the base is located on both sides of the piezoelectric sheet, the electrode structure is located on the two side edges of the piezoelectric sheet, and the intersection of the piezoelectric sheet and the electrode structure has a hollow area, so that the piezoelectric sheet and the electrode structure region are connected by a bridge.

10. The system wake-up piezoelectric microphone module of claim 9, wherein: The piezoelectric sheet also has a hollow area extending from the intersection of the piezoelectric sheet and the electrode structure to the middle of the piezoelectric sheet, so as to divide the piezoelectric sheet into a first part and a second part, and the first part and the second part are connected by a bridge.

11. The system wake-up piezoelectric microphone module of claim 1, wherein: The wake-up chip comprises a MOS tube, the wake-up piezoelectric microphone is connected to the gate of the MOS tube, and the threshold voltage of the MOS tube is lower than the wake-up electric signal voltage generated after the wake-up piezoelectric microphone receives sound waves.

12. The system wake-up piezoelectric microphone module of claim 1, wherein: Further comprising a PCB circuit board and a shell, the wake-up piezoelectric microphone, the wake-up chip, the pickup microphone and the processing chip are arranged on the PCB circuit board and realize the electrical connection of the wake-up piezoelectric microphone, the wake-up chip, the pickup microphone and the processing chip, and the top of the shell is provided with a sound inlet hole.

13. The system wake-up piezoelectric microphone module of claim 1, wherein: Further comprising a PCB circuit board and a shell, the wake-up piezoelectric microphone, the wake-up chip, the pickup microphone and the processing chip are arranged on the PCB circuit board and realize the electrical connection of the wake-up piezoelectric microphone, the wake-up chip, the pickup microphone and the processing chip, and the PCB circuit board is provided with a first sound inlet hole corresponding to the wake-up piezoelectric microphone and a second sound inlet hole corresponding to the pickup microphone.

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