Driving device, control method thereof and electronic equipment

Abstract

The invention discloses a driving device, a control method thereof and electronic equipment, and belongs to the technical field of electronic equipment. The driving device comprises a charge pump circuit, the input end of the charge pump circuit is used for receiving a voltage signal, the first output end of the charge pump circuit is used for outputting a positive voltage signal, and the second output end of the charge pump circuit is used for outputting a negative voltage signal; the first input end of the switching circuit is connected with the first output end of the charge pump circuit, and the second input end of the switching circuit is connected with the second output end of the charge pump circuit; the input end of the buffer circuit is connected with the output end of the switching circuit, and the output end of the buffer circuit is connected with the piezoelectric ultrasonic transducer; wherein the switching circuit alternately transmits a positive pressure signal and a negative pressure signal to the buffer circuit so as to transmit a driving signal to the piezoelectric ultrasonic transducer through the buffer circuit.

Description

Technical Field

[0001] The present application belongs to the technical field of electronic equipment, and specifically relates to a driving device and a control method thereof and an electronic equipment. Background Art

[0002] With the development of technology, many electronic devices choose to use ultrasonic fingerprint sensors for fingerprint recognition. Among them, the ultrasonic fingerprint sensor generates a high-voltage signal through the driving circuit to power the piezoelectric ultrasonic transducer (PUMT, piezoelectric Micromachined Ultrasonic Transducer) array. The piezoelectric ultrasonic transducer generates mechanical vibrations to emit sound waves, and fingerprint recognition is performed by reflecting the sound waves from the finger.

[0003] Related technologies all use a rectifier bridge and an LC (inductor-capacitor) resonant circuit as the driving circuit for the piezoelectric ultrasonic transducer. This driving circuit design requires an external inductor, has the problem of high hardware cost and large circuit size, and is not conducive to miniaturization or integrated design. Summary of the invention

[0004] The purpose of the embodiments of the present application is to provide a driving device and a control method thereof and an electronic device, which solves the problems of high hardware cost of the driving circuit, large circuit volume, and being unfavorable for miniaturized design or integrated design.

[0005] In a first aspect, an embodiment of the present application provides a driving device, which is applied to a piezoelectric ultrasonic transducer, and the driving device includes: a charge pump circuit, wherein the input end of the charge pump circuit is used to receive a voltage signal, the first output end of the charge pump circuit is used to output a positive voltage signal, and the second output end of the charge pump circuit is used to output a negative voltage signal; a switching circuit, wherein the first input end of the switching circuit is connected to the first output end of the charge pump circuit, and the second input end of the switching circuit is connected to the second output end of the charge pump circuit; a buffer circuit, wherein the input end of the buffer circuit is connected to the output end of the switching circuit, and the output end of the buffer circuit is connected to the piezoelectric ultrasonic transducer; wherein the switching circuit alternately transmits positive pressure signals and negative pressure signals to the buffer circuit, so as to transmit a driving signal to the piezoelectric ultrasonic transducer through the buffer circuit.

[0006] In a second aspect, an embodiment of the present application provides an electronic device, comprising: a driving device in any of the above-mentioned technical solutions; an ultrasonic fingerprint sensing device, the ultrasonic fingerprint sensing device comprising a piezoelectric ultrasonic transducer, the driving device being connected to the piezoelectric ultrasonic transducer, and the driving device being used to drive the piezoelectric ultrasonic transducer.

[0007] In a third aspect, an embodiment of the present application provides a control method, which is applied to the driving device in any of the above technical solutions, and the control method includes:

[0008] Controlling the charge pump circuit to transmit positive voltage signals and negative voltage signals to the switch circuit;

[0009] The switch circuit is controlled to transmit a positive pressure signal and a negative pressure signal to the buffer circuit alternately, so as to transmit a driving signal to the piezoelectric ultrasonic transducer through the buffer circuit.

[0010] In a fourth aspect, an embodiment of the present application provides an electronic device, including a processor and a memory, wherein the memory stores programs or instructions that can be executed on the processor, and when the programs or instructions are executed by the processor, the steps of the method of the third aspect are implemented.

[0011] In a fifth aspect, an embodiment of the present application provides a readable storage medium, on which a program or instruction is stored, and when the program or instruction is executed by a processor, the steps of the method of the third aspect are implemented.

[0012] In a sixth aspect, an embodiment of the present application provides a chip, comprising a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run programs or instructions to implement the steps of the method of the third aspect.

[0013] In a seventh aspect, an embodiment of the present application provides a computer program product, which is stored in a storage medium and is executed by at least one processor to implement the method of the third aspect.

[0014] In the embodiment of the present application, by providing a charge pump circuit for negatively boosting the voltage signal in the driving device, there is no need to provide an LC oscillation circuit in the driving device. Therefore, there is no need to provide an inductor element in the driving device, thereby reducing the circuit size of the driving device, solving the problem of high hardware cost of the driving circuit, large circuit volume, and being unfavorable for miniaturization design or integrated design. In addition, the charge pump circuit can continuously maintain the output of high-level positive voltage signals and negative voltage signals, and there is no problem of signal attenuation, thereby further improving the performance of the driving device. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 One of the circuit diagrams of the driving device provided in some embodiments of the present application is shown;

[0016] Figure 2 shows a structural block diagram of a driving device provided in some embodiments of the present application;

[0017] Figure 3 A second circuit diagram of a driving device provided in some embodiments of the present application is shown;

[0018] Figure 4 A third circuit diagram of a driving device provided in some embodiments of the present application is shown;

[0019] Figure 5 One of the level waveform diagrams of the switch element in the charge pump circuit provided in some embodiments of the present application is shown;

[0020] Figure 6 The second level waveform diagram of the switch element in the charge pump circuit provided in some embodiments of the present application is shown;

[0021] Figure 7 One of the level waveform diagrams of the switch element in the switch circuit provided in some embodiments of the present application is shown;

[0022] Figure 8 The second level waveform diagram of the switch element in the switch circuit provided in some embodiments of the present application is shown;

[0023] Fig. 9 One of the voltage-time waveform diagrams provided in some embodiments of the present application is shown;

[0024] Fig.10 The second voltage-time waveform diagram provided in some embodiments of the present application is shown;

[0025] Fig.11 A schematic block diagram of an electronic device provided in some embodiments of the present application is shown;

[0026] Fig.12 A flow chart showing a control method provided in some embodiments of the present application is shown;

[0027] Fig.13 A schematic block diagram of a control device provided in some embodiments of the present application is shown;

[0028] Fig.14 A structural block diagram of an electronic device according to an embodiment of the present application is shown;

[0029] Fig.15 A schematic diagram of the hardware structure of an electronic device provided in some embodiments of the present application is shown.

[0030] Figures 1 to 4 The reference numerals are as follows:

[0031] 100 driving device, 110 charge pump circuit, 112 positive pressure amplifying module, 114 negative pressure amplifying module, 120 switching circuit, 130 buffer circuit, 200 piezoelectric ultrasonic transducer, S1 first switch element, S2 second switch element, S3 third switch element, S4 fourth switch element, S5 fifth switch element, S6 sixth switch element, S7 seventh switch element, S8 eighth switch element, S9 ninth switch element, S10 tenth switch element, S11 eleventh switch element, S12 second switch element, S13 thirteenth switch element, S14 fourteenth switch element, C1 first capacitor, C2 second capacitor, C3 third capacitor, C4 fourth capacitor, C5 fifth capacitor, C6 sixth capacitor. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application belong to the scope of protection of this application.

[0033] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the terms used in this way are interchangeable where appropriate, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0034] The following is combined with Figures 1 to 15 , the driving device and its control method and electronic device provided in the embodiments of the present application are described in detail through specific embodiments and their application scenarios.

[0035] In some embodiments of the present application, a driving device is provided for driving a piezoelectric ultrasonic transducer. Figure 1 One of the circuit diagrams of the driving device provided in some embodiments of the present application is shown, Figure 2 : shows a structural block diagram of a driving device provided in some embodiments of the present application, such as Figure 1 and Figure 2 As shown, the driving device 100 includes:

[0036] A charge pump circuit 110, wherein an input end of the charge pump circuit 110 is used to receive a voltage signal, a first output end of the charge pump circuit 110 is used to output a positive voltage signal, and a second output end of the charge pump circuit is used to output a negative voltage signal, wherein the positive voltage signal and the negative voltage signal are signals obtained by boosting the voltage signal by the charge pump circuit 110;

[0037] A switch circuit 120, wherein a first input terminal of the switch circuit 120 is connected to a first output terminal of the charge pump circuit 110, and a second input terminal of the switch circuit 120 is connected to a second output terminal of the charge pump circuit 110;

[0038] A buffer circuit 130, wherein an input end of the buffer circuit 130 is connected to an output end of the switch circuit 120, and an output end of the buffer circuit 130 is connected to the piezoelectric ultrasonic transducer 200;

[0039] The switch circuit 120 transmits a positive pressure signal and a negative pressure signal to the buffer circuit 130 alternately, so as to transmit a driving signal to the piezoelectric ultrasonic transducer 200 through the buffer circuit 130 .

[0040] In the embodiment of the present application, a charge pump circuit 110, a switch circuit 120 and a buffer circuit 130 are provided in the driving device 100. Among them, the input end of the charge pump circuit 110 receives a voltage signal, and the charge pump circuit 110 can perform positive voltage boost and negative voltage boost on the received voltage signal. The charge pump circuit 110 can play a role of positive and negative voltage boost in the driving device 100, and there is no need to set an LC resonant circuit in the driving device 100. The charge pump circuit 110 includes two output ends, and the first output end and the second output end of the charge circuit are respectively connected to the first input end and the second input end of the switch circuit 120. The positive voltage signal obtained by boosting the charge pump circuit 110 is transmitted to the switch circuit 120 through the first input end, and the negative voltage signal obtained by boosting the charge pump circuit 110 is transmitted to the switch circuit 120 through the second input end. The output end of the switching circuit 120 is connected to the input end of the buffer circuit 130, and the output end of the buffer circuit 130 is connected to the piezoelectric ultrasonic transducer 200. The switching circuit 120 can transmit the positive pressure signal and the negative pressure signal to the buffer circuit 130 alternately, and the buffer circuit 130 can enhance the driving capability of the positive pressure signal and the negative pressure signal, thereby ensuring the working effect of the piezoelectric ultrasonic transducer 200.

[0041] Specifically, the switch circuit 120 can control the on-off state between the first input terminal of the switch circuit 120 and the first output terminal of the charge pump circuit 110, and control the on-off state between the second input terminal of the switch circuit 120 and the second output terminal of the charge pump circuit 110. When the charge pump circuit 110 is running, the first input terminal of the switch circuit 120 receives a positive pressure signal, and the second input terminal of the switch circuit 120 receives a negative pressure signal. When the switch circuit 120 controls the first input terminal to be turned on and the second input terminal to be turned off, the positive pressure signal is transmitted to the piezoelectric ultrasonic transducer 200 through the buffer circuit 130, and when the switch circuit 120 controls the first input terminal to be turned off and the second input terminal to be turned on, the negative pressure signal is transmitted to the piezoelectric ultrasonic transducer 200 through the buffer circuit 130. The switch circuit 120 controls the first input terminal and the second input terminal to be turned on alternately, so that the positive pressure signal and the negative pressure signal are alternately transmitted to the piezoelectric ultrasonic transducer 200 through the buffer circuit 130 to transmit the driving signal, wherein the driving signal includes the positive pressure signal and the negative pressure signal passing through the buffer circuit 130.

[0042] It should be noted that the frequency of the output drive signal can be adjusted by adjusting the frequency at which the switch circuit 120 alternately conducts the first input terminal and the second input terminal, so that the piezoelectric ultrasonic transducer 200 operates at an optimal frequency.

[0043] In the embodiment of the present application, by providing a charge pump circuit 110 for negatively boosting the voltage signal in the driving device 100, there is no need to provide an LC oscillation circuit in the driving device 100. Therefore, there is no need to provide an inductor element in the driving device 100, thereby reducing the circuit size of the driving device 100, solving the problem of high hardware cost of the driving circuit, large circuit volume, and being unfavorable for miniaturization design or integrated design. In addition, the charge pump circuit 110 can continuously maintain the output of high-level positive voltage signals and negative voltage signals, and there is no problem of signal attenuation, thereby further improving the performance of the driving device 100.

[0044] like Figure 1 As shown, in some embodiments of the present application, the charge pump circuit 110 includes:

[0045] A positive pressure amplification module 112, wherein a first end of the positive pressure amplification module 112 is used to receive a voltage signal, and a second end of the positive pressure amplification module 112 is connected to a first input end of the switch circuit 120, wherein the positive pressure amplification module 112 is used to transmit a positive pressure signal to the buffer circuit 130 when the first input end of the switch circuit 120 is turned on;

[0046] A negative voltage amplifier module 114, wherein the first end of the negative voltage amplifier module 114 is used to receive a voltage signal, and the second end of the negative voltage amplifier module 114 is connected to the second input end of the switch circuit 120, wherein the negative voltage amplifier module 114 is used to transmit a negative voltage signal to the buffer circuit 130 when the second input end of the switch circuit 120 is turned on.

[0047] In an embodiment of the present application, the charge pump circuit 110 includes a positive voltage amplifier module 112 and a negative voltage amplifier module. The positive voltage amplifier module 112 and the negative voltage amplifier module 114 are respectively used to perform positive voltage boosting and negative voltage boosting on the voltage. The positive voltage amplifier module 112 obtains a positive voltage signal after performing positive voltage boosting on the voltage signal, and the negative voltage amplifier module 114 obtains a negative voltage signal after performing negative voltage boosting on the voltage signal.

[0048] Specifically, the first end of the positive pressure amplification module 112 is an input end, the second end of the positive pressure amplification module 112 is an input end, the voltage signal is input to the positive pressure amplification module 112 through the first end of the positive pressure amplification module 112, and after the positive pressure amplification module 112 amplifies the voltage signal, the positive pressure amplification module 112 transmits the positive pressure signal to the first input end of the switch circuit 120 through the second end of the positive pressure amplification module 112. The first end of the negative pressure amplification module 114 is an input end, the second end of the negative pressure amplification module 114 is an input end, the voltage signal is input to the negative pressure amplification module 114 through the first end of the negative pressure amplification module 114, and after the negative pressure amplification module 114 amplifies the voltage signal, the negative pressure signal is transmitted to the second input end of the switch circuit 120 through the second end of the negative pressure amplification module 114.

[0049] In an embodiment of the present application, a positive voltage amplifier circuit and a negative voltage amplifier circuit are provided in the charge pump circuit 110, and the positive voltage amplifier circuit and the negative voltage amplifier circuit respectively perform positive voltage amplification and negative voltage amplification on the input voltage signal, so that the charge pump circuit 110 can synchronously transmit positive voltage signals and negative voltage signals to the first input terminal and the second input terminal of the switching circuit 120.

[0050] like Figure 1As shown, in some embodiments of the present application, the positive voltage amplification module 112 includes: a first switch element S1, wherein the first end of the first switch element S1 is used to receive a voltage signal; a second switch element S2, wherein the first end of the second switch element S2 is connected to the second end of the first switch element S1, and the second end of the second switch element S2 is connected to the first input end of the switch circuit 120; a third switch element S3, wherein the first end of the third switch element S3 is connected to the first end of the first switch element S1; a first capacitor C1, wherein the first end of the first capacitor C1 is connected to the second end of the first switch element S1, and the second end of the first capacitor C1 is connected to the second end of the third switch element S3; a fourth switch element S4, wherein the first end of the fourth switch element S4 is connected to the second end of the third switch element S3, and the second end of the fourth switch element S4 is grounded; a second capacitor C2, wherein the first end of the second capacitor C2 is connected to the second end of the second switch element S2, and the second end of the second capacitor C2 is connected to the second end of the fourth switch element S4.

[0051] In the embodiment of the present application, the first end of the first switch element S1 is used to receive a voltage signal, the second switch element S2 is connected between the first switch element S1 and the first input end of the switch circuit 120, and the second end of the second switch element S2 is the output end of the positive voltage amplifier module 112. The third switch element S3 is connected in parallel with the first switch element S1, and a first capacitor C1 is arranged between the second end of the third switch element S3 and the second end of the first switch element S1. The first capacitor C1 serves as a fly capacitor in the positive voltage amplifier module 112. The first capacitor C1 can store and release charges to achieve voltage conversion. The fourth switch element S4 is connected between the third switch element S3 and the ground terminal, and a second capacitor C2 is arranged between the second end of the fourth switch element S4 and the second end of the second switch element S2. The second capacitor C2 is the output capacitor in the positive voltage amplifier module 112.

[0052] In an embodiment of the present application, by controlling the on and off states of the first switch element S1, the second switch element S2, the third switch element S3 and the fourth switch element S4, the operation of the positive pressure amplification module 112 can be controlled, so that the positive pressure amplification module 112 transmits a positive pressure signal to the first input terminal of the switching circuit 120.

[0053] Figure 3 FIG. 2 shows a second circuit diagram of the driving device 100 provided in some embodiments of the present application. Figure 4 FIG. 3 shows a circuit diagram of the driving device 100 provided in some embodiments of the present application. Figure 3 and Figure 4As shown, specifically, the operation of the positive voltage amplification module 112 includes two stages. In the first stage, the first capacitor C1 is charged by controlling the first switch S1 and the fourth switch S4 to be turned on, and controlling the second switch S2 and the third switch S3 to be turned off. At this time, the voltage signal flows through the first switch S1, the first capacitor C1 and the fourth switch S4 in sequence, thereby charging the first capacitor C1, and the voltage across the first capacitor C1 is Vin. In the second stage, the first switch S1 and the fourth switch S4 are controlled to be turned off, and the second switch S2 and the third switch S3 are controlled to be turned on. At this time, the voltage signal flows through the third switch S3, the first capacitor C1 and the fourth switch S4 in sequence. Since the voltage across the first capacitor C1 cannot suddenly change, the voltage Vout1 at the second end of the second switch S2 is raised to 2Vin, completing the positive voltage boost of the voltage signal.

[0054] In an embodiment of the present application, by setting a first switch element S1, a second switch element S2, a third switch element S3 and a fourth switch element S4, as well as a first capacitor C1 as a flying capacitor and a second capacitor C2 as an output capacitor in the positive pressure amplification module 112, and by controlling the on and off states of the first switch element S1, the second switch element S2, the third switch element S3 and the fourth switch element S4, the positive pressure amplification module 112 can perform positive pressure amplification on the received voltage signal, thereby stably transmitting the positive pressure signal to the first input terminal of the switching circuit 120.

[0055] like Figure 1 As shown, in some embodiments of the present application, the negative pressure amplification module 114 includes:

[0056] A fifth switch element S5, wherein a first end of the fifth switch element S5 is used for receiving a voltage signal;

[0057] a sixth switch element S6, wherein a first end of the sixth switch element S6 is connected to a second end of the fifth switch element S5, and a second end of the sixth switch element S6 is grounded;

[0058] A seventh switch element S7, a first end of the seventh switch element S7 is grounded;

[0059] a third capacitor C3, wherein a first end of the third capacitor C3 is connected to a second end of the fifth switch element S5, and a second end of the third capacitor C3 is connected to a second end of the seventh switch element S7;

[0060] an eighth switch element S8, wherein a first end of the eighth switch element S8 is connected to a second end of the third capacitor C3;

[0061] a fourth capacitor C4, wherein a first end of the fourth capacitor C4 is connected to a second end of the sixth switch element S6, and a second end of the fourth capacitor C4 is connected to a second end of the eighth switch element S8;

[0062] A ninth switch element S9, wherein a first end of the ninth switch element S9 is used for receiving a voltage signal;

[0063] a tenth switch element S10, wherein a first end of the tenth switch element S10 is connected to a second end of the ninth switch element S9;

[0064] an eleventh switch element S11, a first end of the eleventh switch element S11 being grounded;

[0065] a fifth capacitor C5, wherein a first end of the fifth capacitor C5 is connected to a second end of the ninth switch element S9, and a second end of the fifth capacitor C5 is connected to a second end of the eleventh switch element S11;

[0066] a twelfth switch element S12, wherein a first end of the twelfth switch element S12 is connected to a second end of the fifth capacitor C5, and a second end of the twelfth switch element S12 is connected to a second input end of the switch circuit 120;

[0067] A sixth capacitor C6, a first end of the sixth capacitor C6 is connected to the second end of the tenth switch element S10, and a second end of the sixth capacitor C6 is connected to the second end of the twelfth switch element S12.

[0068] In the embodiment of the present application, the first end of the fifth switch element S5 is used to receive a voltage signal, and the sixth switch element S6 is connected between the fifth switch element S5 and the ground terminal. The seventh switch element S7 is connected in parallel with the fifth switch element S5, and a third capacitor C3 is provided between the second end of the seventh switch element S7 and the second end of the fifth switch element S5. The third capacitor C3 is used as a fly capacitor in the negative voltage amplification module 114, and the third capacitor C3 can store and release charges to achieve voltage conversion. The first end of the eighth switch element S8 is connected to the second end of the seventh switch element S7, and a fourth capacitor C4 is provided between the second end of the eighth switch element S8 and the second end of the sixth switch element S6. The fourth capacitor C4 is the output capacitor in the negative voltage amplification module 114. The first end of the ninth switch element S9 is used to receive a voltage signal, and the tenth switch element S10 is connected between the ninth switch element S9 and the first input end of the switch circuit 120, and the second end of the tenth switch element S10 is connected to the second end of the eighth switch element S8. The eleventh switch element S11 is connected in parallel with the ninth switch element S9, and a fifth capacitor C5 is provided between the second end of the eleventh switch element S11 and the second end of the ninth switch element S9, and the fifth capacitor C5 is used as a fly capacitor in the negative voltage amplification module 114, and the fifth capacitor C5 can store and release charges to achieve voltage conversion. The twelfth switch element S12 is connected between the eleventh switch element S11 and the second input end of the switch circuit 120, and a sixth capacitor C6 is provided between the second end of the twelfth switch element S12 and the second end of the tenth switch element S10, and the sixth capacitor C6 is the output capacitor in the negative voltage amplification module 114.

[0069] In the embodiment of the present application, by controlling the on and off states of the fifth switch element S5, the sixth switch element S6, the seventh switch element S7, the eighth switch element S8, the ninth switch element S9, the tenth switch element S10, the eleventh switch S11 and the twelfth switch element S12, the operation of the negative pressure amplification module 114 can be controlled, so that the negative pressure amplification module 114 transmits a negative pressure signal to the second input terminal of the switching circuit 120.

[0070] like Figure 3 and Figure 4 As shown, specifically, the operation of the negative voltage amplification module 114 includes two stages. In the first stage, the third capacitor C3 and the fifth capacitor C5 are charged by controlling the fifth switch element S5 and the seventh switch element S7 to be turned on, and controlling the sixth switch element S6 and the eighth switch element S8 to be turned off. At this time, the voltage signal flows through the fifth switch element S5, the third capacitor C3 and the seventh switch element S7 in sequence, thereby charging the third capacitor C3, and by controlling the ninth switch element S9 and the eleventh switch element S11 to be turned on, and controlling the tenth switch element S10 and the twelfth switch element S12 to be turned off, thereby charging the fifth capacitor C5. The voltage across the first capacitor C1 and the fifth capacitor C5 is Vin. In the second stage, the fifth switch element S5 and the seventh switch element S7 are controlled to be disconnected, and the sixth switch element S6 and the eighth switch element S8 are controlled to be turned on. At this time, the voltage signal flows through the sixth switch element S6, the third capacitor C3 and the eighth switch element S8 in sequence. Since the voltage across the third capacitor C3 cannot suddenly change, the voltage Vout2 at the second end of the eighth switch element S8 is reduced to -Vin, the ninth switch element S9 and the eleventh switch element S11 are controlled to be disconnected, and the tenth switch element S10 and the twelfth switch element S12 are controlled to be turned on. At this time, the voltage signal flows through the tenth switch element S10, the fifth capacitor C5 and the twelfth switch element S12 in sequence. Since the voltage across the fifth capacitor C5 cannot suddenly change, the voltage Vout3 at the second end of the twelfth switch element S12 is reduced to -2Vin. The second end of the twelfth switch element S12 is the output end of the negative voltage amplification module 114, and is connected to the second input end of the switch circuit 120, so as to complete the negative voltage boosting of the voltage signal.

[0071] In the embodiment of the present application, by setting the fifth switch element S5, the sixth switch element S6, the seventh switch element S7, the eighth switch element S8, the ninth switch element S9, the tenth switch element S10, the eleventh switch S11 and the twelfth switch element S12 in the negative pressure amplification module 114, as well as the third capacitor C3 and the fifth capacitor C5 as flying capacitors and the fourth capacitor C4 and the sixth capacitor C6 as output capacitors, and by controlling the on and off states of the fifth switch element S5, the sixth switch element S6, the seventh switch element S7, the eighth switch element S8, the ninth switch element S9, the tenth switch element S10, the eleventh switch S11 and the twelfth switch element S12, the negative pressure amplification module 114 can negatively amplify the received voltage signal, thereby stably transmitting the negative pressure signal to the first input end of the switch circuit 120.

[0072] Figure 5 1 shows one of the level waveform diagrams of the switch element in the charge pump circuit 110 provided in some embodiments of the present application, Figure 6 FIG. 2 shows a second level waveform diagram of a switch element in the charge pump circuit 110 provided in some embodiments of the present application, such as Figure 5 As shown, in the first stage, the first switch element S1, the fourth switch element S4, the fifth switch element S5, the seventh switch element S7, the ninth switch element S9 and the eleventh switch element S11 are at a high level, that is, the first switch element S1, the fourth switch element S4, the fifth switch element S5, the seventh switch element S7, the ninth switch element S9 and the eleventh switch element S11 are controlled to be in a conducting state. Figure 6 As shown, in the second stage, the second switch element S2, the third switch element S3, the sixth switch element S6, the tenth switch element S10 and the twelfth switch element S12 are at a high level, that is, in the second stage, the second switch element S2, the third switch element S3, the sixth switch element S6, the eighth switch element S8, the tenth switch element S10 and the twelfth switch element S12 are in the on state.

[0073] Figure 7 1 shows one of the level waveform diagrams of the switch element in the switch circuit 120 provided in some embodiments of the present application, Figure 8 FIG. 2 shows a second level waveform diagram of a switch element in a switch circuit 120 provided in some embodiments of the present application, such as Figure 7 and Figure 8 As shown, the thirteenth switch element S13 and the fourteenth switch element S14 are switched alternately.

[0074] Fig. 9 One of the voltage-time waveform diagrams provided in some embodiments of the present application is shown. Fig.10 FIG. 2 shows a voltage-time waveform diagram of some embodiments of the present application. Fig. 9 and Fig.10As shown, when the voltage signal is Vin, the positive voltage signal output by the first output terminal of the charge pump circuit 110 is 2Vin, the negative voltage signal output by the second output terminal of the charge pump circuit 110 is -2Vin, and the voltage between the second end of the tenth switch element S10 and the second end of the eighth switch element S8 is -Vin.

[0075] like Figure 1 As shown, in some embodiments of the present application, the switching circuit 120 includes: a thirteenth switch element S13, a first end of the thirteenth switch element S13 is connected to the first output end of the charge pump circuit 110, and a second end of the thirteenth switch element S13 is connected to the input end of the buffer circuit 130; a fourteenth switch element S14, a first end of the fourteenth switch element S14 is connected to the second output end of the charge pump circuit 110, and a second end of the fourteenth switch element S14 is connected to the input end of the buffer circuit 130.

[0076] In the embodiment of the present application, the switch circuit 120 includes a thirteenth switch element S13 and a fourteenth switch element S14, wherein adjusting the on-off state of the thirteenth switch element S13 can switch whether the positive voltage signal is transmitted to the buffer circuit 130, and adjusting the on-off state of the fourteenth switch element S14 can switch whether the negative voltage signal is transmitted to the buffer circuit 130.

[0077] Specifically, the first end of the thirteenth switch element S13 serves as the first input end of the switch circuit 120, the second end of the fourteenth switch element S14 serves as the second input end of the switch circuit 120, and the second end of the thirteenth switch element S13 is connected to the second end of the fourteenth switch element S14. By controlling the thirteenth switch element S13 to be in the on state and the fourteenth switch element S14 to be in the off state, the first input end of the switch circuit 120 can be in the on state, and the second input end of the switch circuit 120 can be in the off state, at which time the switch circuit 120 can transmit the positive voltage signal to the buffer circuit 130. By controlling the thirteenth switch element S13 to be in the off state and the fourteenth switch element S14 to be in the on state, the first input end of the switch circuit 120 can be in the off state, and the second input end of the switch circuit 120 can be in the on state, at which time the switch circuit 120 can transmit the negative voltage signal to the buffer circuit 130.

[0078] In the embodiment of the present application, a thirteenth switch element S13 and a fourteenth switch element S14 capable of switching the on-off state are provided in the switch circuit 120. In the process of the charge pump circuit 110 transmitting the positive pressure signal and the negative pressure signal to the switch circuit 120, the on-off state of the thirteenth switch element S13 and the fourteenth switch element S14 are alternately controlled, so that the positive pressure signal and the negative pressure signal are alternately transmitted to the buffer signal, so that the buffer signal transmits the alternately received positive pressure signal and negative pressure signal as a driving signal to the piezoelectric ultrasonic transducer 200 to drive the piezoelectric ultrasonic transducer 200.

[0079] In some embodiments of the present application, the thirteenth switch element S13 and the fourteenth switch element S14 are alternately turned on according to a target frequency, wherein the signal frequency of the driving signal matches the target frequency.

[0080] In the embodiment of the present application, the target frequency is the alternating frequency of the thirteenth switch element S13 and the fourteenth switch element S14 being alternately turned on, and the signal frequency is the signal frequency of the output drive signal. By controlling the thirteenth switch element S13 and the tenth switch element S10 to be alternately turned on, the drive signal can be transmitted to the piezoelectric ultrasonic transducer 200 through the buffer circuit 130, and the signal frequency of the drive signal matches the target frequency of the alternating conduction. It should be noted that the signal frequency corresponding to the target frequency can be selected as a frequency point in the optimal frequency range for the piezoelectric ultrasonic transducer 200 to work.

[0081] Exemplarily, before starting to control the driving device 100 to drive the piezoelectric ultrasonic transducer 200, the optimal frequency point of the piezoelectric ultrasonic transducer 200 is obtained, and the target frequency of alternating conduction is determined according to the optimal frequency point, so that the driven piezoelectric ultrasonic transducer 200 operates at the optimal frequency point.

[0082] In the embodiment of the present application, by adjusting the target frequency of the alternating conduction of the thirteenth switch element S13 and the fourteenth switch element S14 in the switch circuit 120, the output drive circuit can drive the piezoelectric ultrasonic transducer 200 to operate at the optimal frequency point, and the signal frequency of the drive signal can be adjusted by adjusting the target frequency of the alternating conduction to adjust the operating frequency of the piezoelectric ultrasonic transducer 200, thereby improving the flexibility of the drive device 100 in driving the piezoelectric ultrasonic transducer 200.

[0083] In some embodiments of the present application, an electronic device is provided. Fig.11 A schematic block diagram of an electronic device provided in some embodiments of the present application is shown. Fig.11As shown, the electronic device 1100 includes: a driving device 100 and an ultrasonic fingerprint sensor device 1110, the ultrasonic fingerprint sensor device 1110 includes a piezoelectric ultrasonic transducer 1112, the driving device 100 is connected to the piezoelectric ultrasonic transducer 1112, the driving device 100 is used to drive the piezoelectric ultrasonic transducer 1112, the driving device 100 is the driving device in any of the above-mentioned implementations, and thus has all the beneficial technical effects of the driving device 100 in any of the above-mentioned embodiments, which will not be described in detail herein.

[0084] Exemplarily, the electronic device also includes a display screen, and the ultrasonic fingerprint sensor device is arranged on the inner side of the display screen.

[0085] In some embodiments of the present application, a control method is provided, which is applied to the driving device in any of the above embodiments. Fig.12 A flow chart of a control method provided in some embodiments of the present application is shown. Fig.12 As shown, the control method includes:

[0086] Step 1202, obtaining a control circuit for controlling the charge pump circuit to transmit a positive pressure signal and a negative pressure signal to the switch circuit;

[0087] In the embodiment of the present application, the charge pump circuit can perform positive voltage boost and negative voltage boost on the received voltage signal, and the charge pump circuit can play the role of positive and negative voltage boost in the driving device, without the need to set up an LC resonant circuit in the driving device. The charge pump circuit includes two output terminals, the first output terminal and the second output terminal of the charge circuit are respectively connected to the first input terminal and the second input terminal of the switch circuit, the positive voltage signal obtained by the charge pump circuit boosting is transmitted to the switch circuit through the first input terminal, and the negative voltage signal obtained by the charge pump circuit boosting is transmitted to the switch circuit through the second input terminal.

[0088] Step 1204 , controlling the switch circuit to alternately transmit positive pressure signals and negative pressure signals to the buffer circuit, so as to transmit a driving signal to the piezoelectric ultrasonic transducer through the buffer circuit.

[0089] In an embodiment of the present application, the output end of the switching circuit is connected to the input end of the buffer circuit, and the output end of the buffer circuit is connected to the piezoelectric ultrasonic transducer. The switching circuit can transmit positive pressure signals and negative pressure signals to the buffer circuit alternately, and the buffer circuit can enhance the driving capability of the positive pressure signal and the negative pressure signal, thereby ensuring the working effect of the piezoelectric ultrasonic transducer.

[0090] Specifically, the switch circuit controls the on-off state between the first input terminal of the switch circuit and the first output terminal of the charge pump circuit, and controls the on-off state between the second input terminal of the switch circuit and the second output terminal of the charge pump circuit. When the charge pump circuit is running, the first input terminal of the switch circuit receives a positive pressure signal, and the second input terminal of the switch circuit receives a negative pressure signal. When the switch circuit controls the first input terminal to be turned on and the second input terminal to be disconnected, the positive pressure signal is transmitted to the piezoelectric ultrasonic transducer through the buffer circuit. When the switch circuit controls the first input terminal to be disconnected and the second input terminal to be turned on, the negative pressure signal is transmitted to the piezoelectric ultrasonic transducer through the buffer circuit. The switch circuit controls the first input terminal and the second input terminal to be turned on alternately, so that the positive pressure signal and the negative pressure signal are alternately transmitted to the piezoelectric ultrasonic transducer through the buffer circuit to transmit the driving signal, wherein the driving signal includes the positive pressure signal and the negative pressure signal passing through the buffer circuit.

[0091] In the embodiment of the present application, the switching circuit alternately controls the first input terminal and the second input terminal to be turned on. Specifically, the switching circuit alternates between a state in which the first input terminal is turned on and the second input terminal is turned off and a state in which the first input terminal is turned off and the second input terminal is turned on, thereby alternately transmitting the positive pressure signal and the negative pressure signal to the buffer circuit, so that the buffer circuit transmits the driving signal to the piezoelectric ultrasonic transducer to drive the piezoelectric ultrasonic transducer.

[0092] In the embodiment of the present application, by providing a charge pump circuit for negatively boosting the voltage signal in the driving device, there is no need to provide an LC oscillation circuit in the driving device. Therefore, there is no need to provide an inductor element in the driving device, thereby reducing the circuit size of the driving device, solving the problem of high hardware cost of the driving circuit, large circuit volume, and being unfavorable for miniaturization design or integrated design. In addition, the charge pump circuit can continuously maintain the output of high-level positive voltage signals and negative voltage signals, and there is no problem of signal attenuation, thereby further improving the performance of the driving device.

[0093] In some embodiments of the present application, the charge pump circuit includes a positive voltage amplification module and a negative voltage amplification module, and the control method includes: controlling the positive voltage amplification module to transmit a positive voltage signal to the first input end of the switching circuit; and controlling the negative voltage amplification module to transmit a negative voltage signal to the second input end of the switching circuit.

[0094] In an embodiment of the present application, the charge pump circuit includes a positive voltage amplifier module and a negative voltage amplifier module, which are respectively used to perform positive voltage boost and negative voltage boost on the voltage. The positive voltage amplifier module obtains a positive voltage signal after performing positive voltage boost on the voltage signal, and the negative voltage amplifier module obtains a negative voltage signal after performing negative voltage boost on the voltage signal.

[0095] Specifically, the charge pump circuit includes a positive pressure amplifier module and a negative pressure amplifier module. When controlling the operation of the charge pump circuit, the switch components in the positive pressure amplifier module and the negative pressure amplifier module are controlled respectively, so that the positive pressure amplifier module outputs a positive pressure signal, and the negative pressure amplifier module outputs a negative pressure signal.

[0096] In an embodiment of the present application, a positive voltage amplifier circuit and a negative voltage amplifier circuit are provided in the charge pump circuit, and the positive voltage amplifier circuit and the negative voltage amplifier circuit respectively perform positive voltage amplification and negative voltage amplification on the input voltage signal, so that the charge pump circuit can synchronously transmit positive voltage signals and negative voltage signals to the first input terminal and the second input terminal of the switching circuit.

[0097] In some embodiments of the present application, the charge pump circuit includes: a first switch element, a second switch element, a third switch element, a fourth switch element and a first capacitor; controlling the positive voltage amplification module to transmit a positive voltage signal to the first input end of the switching circuit includes: controlling the first switch element and the fourth switch element to be turned on, and controlling the second switch element and the third switch element to be turned off, to charge the first capacitor; controlling the first switch element and the fourth switch element to be turned off, and controlling the second switch element and the third switch element to be turned on, to transmit the positive voltage signal to the first input end of the switching circuit.

[0098] In an embodiment of the present application, the first end of the first switch element is used to receive a voltage signal, the second switch element is connected between the first switch element and the first input end of the switch circuit, and the second end of the second switch element is the output end of the positive voltage amplifier module. The third switch element is connected in parallel with the first switch element, and a first capacitor is arranged between the second end of the third switch element and the second end of the first switch element. The first capacitor serves as a fly capacitor in the positive voltage amplifier module, and the first capacitor can store and release charge to achieve voltage conversion. The fourth switch element is connected between the third switch element and the ground terminal, and a second capacitor is arranged between the second end of the fourth switch element and the second end of the second switch element. The second capacitor is the output capacitor in the positive voltage amplifier module.

[0099] In an embodiment of the present application, by controlling the on and off states of the first switch element, the second switch element, the third switch element and the fourth switch element, the operation of the positive pressure amplification module can be controlled, so that the positive pressure amplification module transmits a positive pressure signal to the first input terminal of the switching circuit.

[0100] The operation of the positive voltage amplifier module includes two stages. In the first stage, the first capacitor is charged by controlling the first switch and the fourth switch to be turned on, and controlling the second switch and the third switch to be turned off. At this time, the voltage signal flows through the first switch, the first capacitor and the fourth switch in sequence, thereby charging the first capacitor. The voltage across the first capacitor is Vin. In the second stage, the first switch and the fourth switch are controlled to be turned off, and the second switch and the third switch are controlled to be turned on. At this time, the voltage signal flows through the third switch, the first capacitor and the fourth switch in sequence. Since the voltage across the first capacitor cannot change suddenly, the voltage Vout1 at the second end of the second switch is raised to 2Vin, completing the positive voltage boost of the voltage signal.

[0101] In an embodiment of the present application, by setting a first switch element, a second switch element, a third switch element and a fourth switch element in the positive pressure amplification module, as well as a first capacitor as a flying capacitor and a second capacitor as an output capacitor, and by controlling the on-off state of the first switch element, the second switch element, the third switch element and the fourth switch element, the positive pressure amplification module can perform positive pressure amplification on the received voltage signal, thereby stably transmitting the positive pressure signal to the first input end of the switching circuit.

[0102] In some embodiments of the present application, the charge pump circuit includes: a fifth switch element, a sixth switch element, a seventh switch element, an eighth switch element, a ninth switch element, a tenth switch element, an eleventh switch element, a twelfth switch element, a third capacitor and a fifth capacitor; controlling the negative voltage amplification module to transmit a negative voltage signal to the second input terminal of the switch circuit, including: controlling the fifth switch element, the seventh switch element, the ninth switch element and the eleventh switch element to be turned on, and controlling the sixth switch element, the eighth switch element, the tenth switch element and the twelfth switch element to be turned off, to charge the third capacitor and the fifth capacitor; controlling the fifth switch element, the seventh switch element, the ninth switch element and the eleventh switch element to be turned off, and controlling the sixth switch element, the eighth switch element, the tenth switch element and the twelfth switch element to be turned on, to transmit the negative voltage signal to the second input terminal of the switch circuit.

[0103] In the embodiment of the present application, the first end of the fifth switch is used to receive a voltage signal, and the sixth switch is connected between the fifth switch and the ground terminal. The seventh switch is connected in parallel with the fifth switch, and a third capacitor is provided between the second end of the seventh switch and the second end of the fifth switch, and the third capacitor is used as a fly capacitor in the negative voltage amplifier module, and the third capacitor can store and release charge to achieve voltage conversion. The first end of the eighth switch is connected to the second end of the seventh switch, and a fourth capacitor is provided between the second end of the eighth switch and the second end of the sixth switch, and the fourth capacitor is the output capacitor in the negative voltage amplifier module. The first end of the ninth switch is used to receive a voltage signal, the tenth switch is connected between the ninth switch and the first input end of the switch circuit, and the second end of the tenth switch is connected to the second end of the eighth switch. The eleventh switch is connected in parallel with the ninth switch, and a fifth capacitor is provided between the second end of the eleventh switch and the second end of the ninth switch, and the fifth capacitor is used as a fly capacitor in the negative voltage amplifier module, and the fifth capacitor can store and release charge to achieve voltage conversion. The twelfth switch element is connected between the eleventh switch element and the second input terminal of the switch circuit. A sixth capacitor is arranged between the second terminal of the twelfth switch element and the second terminal of the tenth switch element. The sixth capacitor is an output capacitor in the negative voltage amplification module.

[0104] In the embodiment of the present application, by controlling the on and off states of the fifth switch element, the sixth switch element, the seventh switch element, the eighth switch element, the ninth switch element, the tenth switch element, the eleventh switch element and the twelfth switch element, the operation of the negative pressure amplification module can be controlled, so that the negative pressure amplification module transmits a negative pressure signal to the second input terminal of the switching circuit.

[0105] The operation of the negative pressure amplification module includes two stages. In the first stage, the third capacitor and the fifth capacitor are charged by controlling the fifth switch element and the seventh switch element to be turned on, and controlling the sixth switch element and the eighth switch element to be turned off. At this time, the voltage signal flows through the fifth switch element, the third capacitor and the seventh switch element in sequence, thereby charging the third capacitor, and by controlling the ninth switch element and the eleventh switch element to be turned on, and controlling the tenth switch element and the twelfth switch element to be turned off, thereby charging the fifth capacitor. The voltage across the first capacitor and the fifth capacitor is Vin. In the second stage, the fifth switch element and the seventh switch element are controlled to be disconnected, and the sixth switch element and the eighth switch element are controlled to be turned on. At this time, the voltage signal flows through the sixth switch element, the third capacitor and the eighth switch element in sequence. Since the voltage across the third capacitor cannot suddenly change, the voltage Vout2 at the second end of the eighth switch element is reduced to -Vin. The ninth switch element and the eleventh switch element are controlled to be disconnected, and the tenth switch element and the twelfth switch element are controlled to be turned on. At this time, the voltage signal flows through the tenth switch element, the fifth capacitor and the twelfth switch element in sequence. Since the voltage across the fifth capacitor cannot suddenly change, the voltage Vout3 at the second end of the twelfth switch element is reduced to -2Vin. The second end of the twelfth switch element is the output end of the negative voltage amplification module and is connected to the second input end of the switch circuit to complete the negative voltage boost of the voltage signal.

[0106] In an embodiment of the present application, by setting a fifth switch element, a sixth switch element, a seventh switch element, an eighth switch element, a ninth switch element, a tenth switch element, an eleventh switch element and a twelfth switch element in the negative pressure amplification module, as well as a third capacitor and a fifth capacitor as flying capacitors and a fourth capacitor and a sixth capacitor as output capacitors, and by controlling the on-off state of the fifth switch element, the sixth switch element, the seventh switch element, the eighth switch element, the ninth switch element, the tenth switch element, the eleventh switch element and the twelfth switch element, the negative pressure amplification module can perform negative pressure amplification on the received voltage signal, thereby stably transmitting the negative pressure signal to the first input terminal of the switching circuit.

[0107] In some embodiments of the present application, the switching circuit includes a thirteenth switching element and a fourteenth switching element; controlling the switching circuit to alternately transmit positive voltage signals and negative voltage signals to the buffer circuit includes: controlling the thirteenth switching element and the fourteenth switching element to alternately conduct according to a target frequency; wherein the signal frequency of the driving signal matches the target frequency.

[0108] In an embodiment of the present application, the switching circuit includes a thirteenth switch element and a fourteenth switch element, wherein adjusting the on-off state of the thirteenth switch element can switch whether the positive voltage signal is transmitted to the buffer circuit, and adjusting the on-off state of the fourteenth switch element can switch whether the negative voltage signal is transmitted to the buffer circuit.

[0109] Specifically, the first end of the thirteenth switch element serves as the first input end of the switch circuit, the second end of the fourteenth switch element serves as the second input end of the switch circuit, and the second end of the thirteenth switch element is connected to the second end of the fourteenth switch element. By controlling the thirteenth switch element to be in the on state and the fourteenth switch element to be in the off state, the first input end of the switch circuit can be in the on state, and the second input end of the switch circuit can be in the off state, at which time the switch circuit can transmit the positive voltage signal to the buffer circuit. By controlling the thirteenth switch element to be in the off state and the fourteenth switch element to be in the on state, the first input end of the switch circuit can be in the off state, and the second input end of the switch circuit can be in the on state, at which time the switch circuit can transmit the negative voltage signal to the buffer circuit.

[0110] In an embodiment of the present application, a thirteenth switch element and a fourteenth switch element capable of switching on and off states are provided in the switch circuit. In the process of the charge pump circuit transmitting the positive pressure signal and the negative pressure signal to the switch circuit, the on and off states of the thirteenth switch element and the fourteenth switch element are alternately controlled, so that the positive pressure signal and the negative pressure signal are alternately transmitted to the buffer signal, so that the buffer signal transmits the alternately received positive pressure signal and negative pressure signal as a driving signal to the piezoelectric ultrasonic transducer to drive the piezoelectric ultrasonic transducer.

[0111] In the embodiment of the present application, the thirteenth switch element and the tenth switch element are controlled to be alternately turned on, so that a driving signal can be transmitted to the piezoelectric ultrasonic transducer through the buffer circuit, and the signal frequency of the driving signal matches the alternating frequency of the alternating conduction.

[0112] It should be noted that before starting to control the driving device to drive the piezoelectric ultrasonic transducer, the optimal frequency point of the piezoelectric ultrasonic transducer is obtained, and the target frequency of alternating conduction is determined according to the optimal frequency point, so that the driven piezoelectric ultrasonic transducer operates at the optimal frequency point.

[0113] The driving device provided in the embodiment of the present application can be executed by an electronic device. In the embodiment of the present application, the driving device provided in the embodiment of the present application is described by taking an electronic device executing the driving device as an example.

[0114] In some embodiments of the present application, a control device is provided, which is applied to the driving device in any of the above embodiments. Fig.13 Schematic block diagram of a control device provided in some embodiments of the present application is shown. Fig.13 As shown, the control device 1300 includes:

[0115] A control module 1302, used to control the charge pump circuit to transmit a positive voltage signal and a negative voltage signal to the switch circuit;

[0116] The control module 1302 is used to control the switch circuit to alternately transmit positive pressure signals and negative pressure signals to the buffer circuit, so as to transmit the driving signal to the piezoelectric ultrasonic transducer through the buffer circuit.

[0117] In the embodiment of the present application, by providing a charge pump circuit for negatively boosting the voltage signal in the driving device, there is no need to provide an LC oscillation circuit in the driving device. Therefore, there is no need to provide an inductor element in the driving device, thereby reducing the circuit size of the driving device, solving the problem of high hardware cost of the driving circuit, large circuit volume, and being unfavorable for miniaturization design or integrated design. In addition, the charge pump circuit can continuously maintain the output of high-level positive voltage signals and negative voltage signals, and there is no problem of signal attenuation, thereby further improving the performance of the driving device.

[0118] In some embodiments of the present application, the charge pump circuit includes a positive voltage amplification module and a negative voltage amplification module;

[0119] A control module 1302, used to control the positive pressure amplification module to transmit a positive pressure signal to the first input end of the switch circuit;

[0120] And control the negative pressure amplification module to transmit a negative pressure signal to the second input end of the switch circuit.

[0121] In an embodiment of the present application, a positive voltage amplifier circuit and a negative voltage amplifier circuit are provided in the charge pump circuit, and the positive voltage amplifier circuit and the negative voltage amplifier circuit respectively perform positive voltage amplification and negative voltage amplification on the input voltage signal, so that the charge pump circuit can synchronously transmit positive voltage signals and negative voltage signals to the first input terminal and the second input terminal of the switching circuit.

[0122] In some embodiments of the present application, the charge pump circuit includes: a first switch element, a second switch element, a third switch element, a fourth switch element and a first capacitor;

[0123] The control module 1302 is used to control the first switch element and the fourth switch element to be turned on, and control the second switch element and the third switch element to be turned off, so as to charge the first capacitor;

[0124] The control module 1302 is used to control the first switch element and the fourth switch element to be disconnected, and control the second switch element and the third switch element to be connected, so as to transmit a positive voltage signal to the first input terminal of the switch circuit.

[0125] In an embodiment of the present application, by setting a first switch element, a second switch element, a third switch element and a fourth switch element in the positive pressure amplification module, as well as a first capacitor as a flying capacitor and a second capacitor as an output capacitor, and by controlling the on-off state of the first switch element, the second switch element, the third switch element and the fourth switch element, the positive pressure amplification module can perform positive pressure amplification on the received voltage signal, thereby stably transmitting the positive pressure signal to the first input end of the switching circuit.

[0126] In some embodiments of the present application, the charge pump circuit includes: a fifth switch element, a sixth switch element, a seventh switch element, an eighth switch element, a ninth switch element, a tenth switch element, an eleventh switch element, a twelfth switch element, a third capacitor, and a fifth capacitor;

[0127] The control module 1302 is used to control the fifth switch element, the seventh switch element, the ninth switch element and the eleventh switch element to be turned on, and control the sixth switch element, the eighth switch element, the tenth switch element and the twelfth switch element to be turned off, so as to charge the third capacitor and the fifth capacitor;

[0128] The control module 1302 is used to control the fifth switch element, the seventh switch element, the ninth switch element and the eleventh switch element to be disconnected, and control the sixth switch element, the eighth switch element, the tenth switch element and the twelfth switch element to be turned on, so as to transmit a negative pressure signal to the second input terminal of the switch circuit.

[0129] In an embodiment of the present application, by setting a fifth switch element, a sixth switch element, a seventh switch element, an eighth switch element, a ninth switch element, a tenth switch element, an eleventh switch element and a twelfth switch element in the negative pressure amplification module, as well as a third capacitor and a fifth capacitor as flying capacitors and a fourth capacitor and a sixth capacitor as output capacitors, and by controlling the on-off state of the fifth switch element, the sixth switch element, the seventh switch element, the eighth switch element, the ninth switch element, the tenth switch element, the eleventh switch element and the twelfth switch element, the negative pressure amplification module can perform negative pressure amplification on the received voltage signal, thereby stably transmitting the negative pressure signal to the first input terminal of the switching circuit.

[0130] In some embodiments of the present application, the switch circuit includes a thirteenth switch element and a fourteenth switch element;

[0131] A control module 1302, configured to control the thirteenth switch element and the fourteenth switch element to be alternately turned on according to a target frequency;

[0132] The signal frequency of the driving signal matches the target frequency.

[0133] In an embodiment of the present application, a thirteenth switch element and a fourteenth switch element capable of switching on and off states are provided in the switch circuit. In the process of the charge pump circuit transmitting the positive pressure signal and the negative pressure signal to the switch circuit, the on and off states of the thirteenth switch element and the fourteenth switch element are alternately controlled, so that the positive pressure signal and the negative pressure signal are alternately transmitted to the buffer signal, so that the buffer signal transmits the alternately received positive pressure signal and negative pressure signal as a driving signal to the piezoelectric ultrasonic transducer to drive the piezoelectric ultrasonic transducer.

[0134] In the embodiment of the present application, the thirteenth switch element and the tenth switch element are controlled to be alternately turned on, so that a driving signal can be transmitted to the piezoelectric ultrasonic transducer through the buffer circuit, and the signal frequency of the driving signal matches the alternating frequency of the alternating conduction.

[0135] The charging device in the embodiment of the present application can be an electronic device, or a component in the electronic device, such as an integrated circuit or a chip. The electronic device can be a terminal, or it can be other devices other than a terminal. Exemplarily, the electronic device can be a mobile phone, a tablet computer, a laptop computer, a PDA, a vehicle-mounted electronic device, a mobile Internet device (Mobile Internet Device, MID), an augmented reality (augmented reality, AR) / virtual reality (virtual reality, VR) device, a robot, a wearable device, an ultra-mobile personal computer (ultra-mobile personal computer, UMPC), a netbook or a personal digital assistant (personal digital assistant, PDA), etc. It can also be a server, a network attached storage (Network Attached Storage, NAS), a personal computer (personal computer, PC), a television (television, TV), a teller machine or a self-service machine, etc., and the embodiment of the present application is not specifically limited.

[0136] The charging device in the embodiment of the present application may be a device having an operating system. The operating system may be an Android operating system, an iOS operating system, or other possible operating systems, which are not specifically limited in the embodiment of the present application.

[0137] The charging device provided in the embodiment of the present application can implement each process implemented in the above method embodiment, and will not be described again here to avoid repetition.

[0138] Optionally, an embodiment of the present application further provides an electronic device, which includes a charging device as in any of the above embodiments, and thus has all the beneficial effects of the driving device in any of the embodiments, which will not be described in detail here.

[0139] Optionally, an embodiment of the present application further provides an electronic device, Fig.14 A structural block diagram of an electronic device according to an embodiment of the present application is shown. Fig.14As shown, the electronic device 1400 includes a processor 1402, a memory 1404, and a program or instruction stored in the memory 1404 and executable on the processor 1402. When the program or instruction is executed by the processor 1402, each process of the above-mentioned driving device embodiment is implemented, and the same technical effect can be achieved. To avoid repetition, it will not be described here.

[0140] It should be noted that the electronic devices in the embodiments of the present application include the above-mentioned mobile electronic devices and non-mobile electronic devices.

[0141] Fig.15 A schematic diagram of the hardware structure of an electronic device to implement an embodiment of the present application.

[0142] The electronic device 1500 includes but is not limited to: a radio frequency unit 1501, a network module 1502, an audio output unit 1503, an input unit 1504, a sensor 1505, a display unit 1506, a user input unit 1507, an interface unit 1508, a memory 1509 and a processor 1510 and other components.

[0143] Those skilled in the art will appreciate that the electronic device 1500 may also include a power source (such as a battery) for supplying power to each component, and the power source may be logically connected to the processor 1510 through a power management system, thereby implementing functions such as managing charging, discharging, and power consumption management through the power management system. Fig.15 The electronic device structure shown in the figure does not constitute a limitation on the electronic device. The electronic device may include more or fewer components than shown in the figure, or combine certain components, or arrange the components differently, which will not be described in detail here.

[0144] The processor 1510 is used to control the charge pump circuit to transmit a positive voltage signal and a negative voltage signal to the switch circuit;

[0145] The processor 1510 is used to control the switch circuit to alternately transmit positive pressure signals and negative pressure signals to the buffer circuit, so as to transmit the driving signal to the piezoelectric ultrasonic transducer through the buffer circuit.

[0146] In the embodiment of the present application, by providing a charge pump circuit for negatively boosting the voltage signal in the driving device, there is no need to provide an LC oscillation circuit in the driving device. Therefore, there is no need to provide an inductor element in the driving device, thereby reducing the circuit size of the driving device, solving the problem of high hardware cost of the driving circuit, large circuit volume, and being unfavorable for miniaturization design or integrated design. In addition, the charge pump circuit can continuously maintain the output of high-level positive voltage signals and negative voltage signals, and there is no problem of signal attenuation, thereby further improving the performance of the driving device.

[0147] In some embodiments of the present application, the charge pump circuit includes a positive voltage amplification module and a negative voltage amplification module;

[0148] Processor 1510, used to control the positive pressure amplification module to transmit a positive pressure signal to the first input end of the switch circuit;

[0149] And control the negative pressure amplification module to transmit a negative pressure signal to the second input end of the switch circuit.

[0150] In an embodiment of the present application, a positive voltage amplifier circuit and a negative voltage amplifier circuit are provided in the charge pump circuit, and the positive voltage amplifier circuit and the negative voltage amplifier circuit respectively perform positive voltage amplification and negative voltage amplification on the input voltage signal, so that the charge pump circuit can synchronously transmit positive voltage signals and negative voltage signals to the first input terminal and the second input terminal of the switching circuit.

[0151] In some embodiments of the present application, the charge pump circuit includes: a first switch element, a second switch element, a third switch element, a fourth switch element and a first capacitor;

[0152] The processor 1510 is used to control the first switch element and the fourth switch element to be turned on, and control the second switch element and the third switch element to be turned off, so as to charge the first capacitor;

[0153] The processor 1510 is used to control the first switch element and the fourth switch element to be disconnected, and control the second switch element and the third switch element to be turned on, so as to transmit a positive voltage signal to the first input terminal of the switch circuit.

[0154] In an embodiment of the present application, by setting a first switch element, a second switch element, a third switch element and a fourth switch element in the positive pressure amplification module, as well as a first capacitor as a flying capacitor and a second capacitor as an output capacitor, and by controlling the on-off state of the first switch element, the second switch element, the third switch element and the fourth switch element, the positive pressure amplification module can perform positive pressure amplification on the received voltage signal, thereby stably transmitting the positive pressure signal to the first input end of the switching circuit.

[0155] In some embodiments of the present application, the charge pump circuit includes: a fifth switch element, a sixth switch element, a seventh switch element, an eighth switch element, a ninth switch element, a tenth switch element, an eleventh switch element, a twelfth switch element, a third capacitor, and a fifth capacitor;

[0156] The processor 1510 is used to control the fifth switch element, the seventh switch element, the ninth switch element, and the eleventh switch element to be turned on, and control the sixth switch element, the eighth switch element, the tenth switch element, and the twelfth switch element to be turned off, so as to charge the third capacitor and the fifth capacitor;

[0157] The processor 1510 is used to control the fifth switch element, the seventh switch element, the ninth switch element and the eleventh switch element to be disconnected, and control the sixth switch element, the eighth switch element, the tenth switch element and the twelfth switch element to be turned on, so as to transmit a negative pressure signal to the second input terminal of the switch circuit.

[0158] In an embodiment of the present application, by setting a fifth switch element, a sixth switch element, a seventh switch element, an eighth switch element, a ninth switch element, a tenth switch element, an eleventh switch element and a twelfth switch element in the negative pressure amplification module, as well as a third capacitor and a fifth capacitor as flying capacitors and a fourth capacitor and a sixth capacitor as output capacitors, and by controlling the on-off state of the fifth switch element, the sixth switch element, the seventh switch element, the eighth switch element, the ninth switch element, the tenth switch element, the eleventh switch element and the twelfth switch element, the negative pressure amplification module can perform negative pressure amplification on the received voltage signal, thereby stably transmitting the negative pressure signal to the first input terminal of the switching circuit.

[0159] In some embodiments of the present application, the switch circuit includes a thirteenth switch element and a fourteenth switch element;

[0160] The processor 1510 is used to control the thirteenth switch element and the fourteenth switch element to be alternately turned on according to the target frequency;

[0161] The signal frequency of the driving signal matches the target frequency.

[0162] In an embodiment of the present application, a thirteenth switch element and a fourteenth switch element capable of switching on and off states are provided in the switch circuit. In the process of the charge pump circuit transmitting the positive pressure signal and the negative pressure signal to the switch circuit, the on and off states of the thirteenth switch element and the fourteenth switch element are alternately controlled, so that the positive pressure signal and the negative pressure signal are alternately transmitted to the buffer signal, so that the buffer signal transmits the alternately received positive pressure signal and negative pressure signal as a driving signal to the piezoelectric ultrasonic transducer to drive the piezoelectric ultrasonic transducer.

[0163] In the embodiment of the present application, the thirteenth switch element and the tenth switch element are controlled to be alternately turned on, so that a driving signal can be transmitted to the piezoelectric ultrasonic transducer through the buffer circuit, and the signal frequency of the driving signal matches the alternating frequency of the alternating conduction.

[0164] It should be understood that in the embodiment of the present application, the input unit 1504 may include a graphics processor (GPU) 15041 and a microphone 15042, and the graphics processor 15041 processes the image data of the static picture or action file obtained by the image capture device (such as a camera) in the action file capture mode or the image capture mode. The display unit 1506 may include a display panel 15061, and the display panel 15061 may be configured in the form of a liquid crystal display, an organic light emitting diode, etc. The user input unit 1507 includes a touch panel 15071 and at least one of other input devices 15072. The touch panel 15071 is also called a touch screen. The touch panel 15071 may include two parts: a touch detection device and a touch controller. Other input devices 15072 may include, but are not limited to, a physical keyboard, function keys (such as volume control keys, switch keys, etc.), a trackball, a mouse, and a joystick, which will not be repeated here.

[0165] The memory 1509 can be used to store software programs and various data. The memory 1509 may mainly include a first storage area for storing programs or instructions and a second storage area for storing data, wherein the first storage area may store an operating system, an application program or instructions required for at least one function (such as a sound playback function, an image playback function, etc.), etc. In addition, the memory 1509 may include a volatile memory or a non-volatile memory, or the memory 1509 may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), a static random access memory (SRAM), a dynamic random access memory (DRAM), a synchronous dynamic random access memory (SDRAM), a double data rate synchronous dynamic random access memory (DDRSDRAM), an enhanced synchronous dynamic random access memory (ESDRAM), a synchronous link dynamic random access memory (SLDRAM) and a direct memory bus random access memory (DRRAM). The memory 1509 in the embodiment of the present application includes but is not limited to these and any other suitable types of memory.

[0166] The processor 1510 may include one or more processing units; optionally, the processor 1510 integrates an application processor and a modem processor, wherein the application processor mainly processes operations related to an operating system, a user interface, and application programs, and the modem processor mainly processes wireless communication signals, such as a baseband processor. It is understandable that the modem processor may not be integrated into the processor 1510.

[0167] An embodiment of the present application also provides a readable storage medium, on which a program or instruction is stored. When the program or instruction is executed by a processor, the various processes of the above-mentioned method embodiment are implemented and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

[0168] The processor is the processor in the electronic device in the above embodiment. The readable storage medium includes a computer readable storage medium, such as a computer read-only memory ROM, a random access memory RAM, a magnetic disk or an optical disk.

[0169] An embodiment of the present application further provides a chip, which includes a processor and a communication interface, the communication interface and the processor are coupled, and the processor is used to run programs or instructions to implement the various processes of the above-mentioned driving device embodiment, and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0170] It should be understood that the chip mentioned in the embodiments of the present application can also be called a system-level chip, a system chip, a chip system or a system-on-chip chip, etc.

[0171] An embodiment of the present application provides a computer program product, which is stored in a storage medium. The program product is executed by at least one processor to implement the various processes of the above-mentioned drive device embodiment and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0172] It should be noted that, in this article, the term "comprises", "includes" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, device, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, device, article or device. In the absence of further restrictions, an element defined by the statement "includes one..." does not exclude the presence of other identical elements in the process, device, article or device including the element. In addition, it should be noted that the scope of the devices and apparatuses in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved, for example, the described device may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0173] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment device can be implemented by means of software plus a necessary general hardware platform, and of course it can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art can be embodied in the form of a computer software product, which is stored in a storage medium (such as ROM / RAM, disk, CD), including a number of instructions for a terminal (which can be a mobile phone, computer, server, or network equipment, etc.) to execute the device of each embodiment of the present application.

[0174] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. A driving device, characterized in that: Used to drive a piezoelectric ultrasonic transducer, the driving device comprises: A charge pump circuit, wherein an input end of the charge pump circuit is used to receive a voltage signal, a first output end of the charge pump circuit is used to output a positive voltage signal, and a second output end of the charge pump circuit is used to output a negative voltage signal, wherein the positive voltage signal and the negative voltage signal are signals obtained by the charge pump circuit by boosting the voltage signal; a switch circuit, wherein a first input terminal of the switch circuit is connected to a first output terminal of the charge pump circuit, and a second input terminal of the switch circuit is connected to a second output terminal of the charge pump circuit; A buffer circuit, wherein an input end of the buffer circuit is connected to an output end of the switch circuit, and an output end of the buffer circuit is connected to the piezoelectric ultrasonic transducer; The switch circuit transmits the positive pressure signal and the negative pressure signal to the buffer circuit alternately, so as to transmit the driving signal to the piezoelectric ultrasonic transducer through the buffer circuit.

2. The driving device according to claim 1, characterized in that: The charge pump circuit comprises: A positive pressure amplification module, wherein a first end of the positive pressure amplification module is used to receive the voltage signal, and a second end of the positive pressure amplification module is connected to a first input end of the switch circuit, wherein the positive pressure amplification module is used to transmit a positive pressure signal to the buffer circuit when the first input end of the switch circuit is turned on; A negative voltage amplification module, wherein the first end of the negative voltage amplification module is used to receive the voltage signal, and the second end of the negative voltage amplification module is connected to the second input end of the switching circuit, wherein the negative voltage amplification module is used to transmit a negative voltage signal to the buffer circuit when the second input end of the switching circuit is turned on.

3. The driving device according to claim 2, characterized in that: The positive pressure amplification module comprises: a first switch element, wherein a first end of the first switch element is used to receive the voltage signal; a second switch element, wherein a first end of the second switch element is connected to a second end of the first switch element, and a second end of the second switch element is connected to a first input end of the switch circuit; a third switch element, a first end of the third switch element being connected to the first end of the first switch element; a first capacitor, wherein a first end of the first capacitor is connected to a second end of the first switch element, and a second end of the first capacitor is connected to a second end of the third switch element; a fourth switch element, wherein a first end of the fourth switch element is connected to a second end of the third switch element, and a second end of the fourth switch element is grounded; A second capacitor, wherein a first end of the second capacitor is connected to a second end of the second switch element, and a second end of the second capacitor is connected to a second end of the fourth switch element.

4. The driving device according to claim 2, characterized in that: The negative pressure amplification module comprises: a fifth switch element, wherein a first end of the fifth switch element is used to receive the voltage signal; a sixth switch element, wherein a first end of the sixth switch element is connected to a second end of the fifth switch element, and a second end of the sixth switch element is grounded; A seventh switch element, a first end of the seventh switch element being grounded; a third capacitor, wherein a first end of the third capacitor is connected to the second end of the fifth switch element, and a second end of the third capacitor is connected to the second end of the seventh switch element; an eighth switch element, wherein a first end of the eighth switch element is connected to a second end of the third capacitor; a fourth capacitor, wherein a first end of the fourth capacitor is connected to a second end of the sixth switch element, and a second end of the fourth capacitor is connected to a second end of the eighth switch element; a ninth switch element, wherein a first end of the ninth switch element is used to receive the voltage signal; a tenth switch element, wherein a first end of the tenth switch element is connected to a second end of the ninth switch element; an eleventh switch element, a first end of the eleventh switch element being grounded; a fifth capacitor, wherein a first end of the fifth capacitor is connected to a second end of the ninth switch element, and a second end of the fifth capacitor is connected to a second end of the eleventh switch element; a twelfth switch element, wherein a first end of the twelfth switch element is connected to a second end of the fifth capacitor, and a second end of the twelfth switch element is connected to a second input end of the switch circuit; A sixth capacitor, wherein a first end of the sixth capacitor is connected to the second end of the tenth switch element, and a second end of the sixth capacitor is connected to the second end of the twelfth switch element.

5. The driving device according to any one of claims 1 to 4, characterized in that: The switch circuit comprises: a thirteenth switch element, wherein a first end of the thirteenth switch element is connected to the first output end of the charge pump circuit, and a second end of the thirteenth switch element is connected to the input end of the buffer circuit; A fourteenth switch element, wherein a first end of the fourteenth switch element is connected to the second output end of the charge pump circuit, and a second end of the fourteenth switch element is connected to the input end of the buffer circuit.

6. The driving device according to claim 5, characterized in that: The thirteenth switch element and the fourteenth switch element are alternately turned on according to a target frequency, wherein a signal frequency of the driving signal matches the target frequency.

7. An electronic device, characterized in that: include: The driving device according to any one of claims 1 to 6; An ultrasonic fingerprint sensor device, wherein the ultrasonic fingerprint sensor device comprises a piezoelectric ultrasonic transducer, the driving device is connected to the piezoelectric ultrasonic transducer, and the driving device is used to drive the piezoelectric ultrasonic transducer.

8. A control method, characterized in that: Applied to the driving device according to any one of claims 1 to 6, the control method comprises: Controlling the charge pump circuit to transmit positive voltage signals and negative voltage signals to the switch circuit; The switch circuit is controlled to alternately transmit the positive pressure signal and the negative pressure signal to the buffer circuit, so as to transmit a driving signal to the piezoelectric ultrasonic transducer through the buffer circuit.

9. The control method according to claim 8, characterized in that: The charge pump circuit includes a positive voltage amplification module and a negative voltage amplification module, and the control method includes: Controlling the positive pressure amplification module to transmit the positive pressure signal to the first input end of the switch circuit; And controlling the negative pressure amplification module to transmit the negative pressure signal to the second input end of the switch circuit.

10. The control method according to claim 9, characterized in that: The charge pump circuit comprises: a first switch element, a second switch element, a third switch element, a fourth switch element and a first capacitor; The controlling the positive pressure amplification module to transmit the positive pressure signal to the first input end of the switch circuit comprises: Controlling the first switch element and the fourth switch element to be turned on, and controlling the second switch element and the third switch element to be turned off, so as to charge the first capacitor; The first switch element and the fourth switch element are controlled to be disconnected, and the second switch element and the third switch element are controlled to be connected, so as to transmit the positive voltage signal to the first input end of the switch circuit.

Images