Transformer driving circuit, ultrasonic transducer driving device and ultrasonic transducer

Abstract

The present application discloses a driving circuit for a transformer, a driving device for an ultrasonic transducer, and an ultrasonic transducer, and relates to the field of electronic technology. The transformer includes a primary port, and the driving circuit includes: a power tube, the power tube is turned on and off to drive the transformer, a first operational amplifier, a first current source, a first switch, and a second switch. In a first state, the first current source outputs a first current, and the first switch is turned on to turn on the power tube. In a second state, the second current source outputs a second current, and the second switch is turned on to turn off the power tube. The solution provided in the embodiment of the present application can solve the oscillation problem caused by the drain voltage coupling caused by the weak gate drive capability when the power tube is switching in the existing transformer driving circuit, and ensure the stability of the output signal during the switching process of the power tube.

Description

Technical Field

[0001] The present invention relates to the field of electronic technology, and in particular to a driving circuit of a transformer, a driving device of an ultrasonic transducer, and an ultrasonic transducer. Background Art

[0002] Nowadays, ultrasonic transducer driving circuit is a key component of ultrasonic system and is widely used in medical ultrasonic diagnosis and industrial non-destructive testing.

[0003] In related technologies, in the ultrasonic transducer's drive circuit, a digital control signal is connected to a power tube via a resistor, thereby controlling the slope of the power tube's gate voltage, thereby controlling the power tube's on / off state. Furthermore, the power tube is combined with a center-tapped transformer to drive the ultrasonic transducer.

[0004] However, in the solution provided by the related technology, the use of a larger resistor will result in a lower driving capability of the power tube gate. During the control signal switching process, the power tube impedance will produce high-frequency oscillations, resulting in waveforms or noise in the output signal, affecting the stability of the ultrasonic transducer and the accuracy of the transmitted signal. Summary of the Invention

[0005] The purpose of the present invention is to provide a transformer driving circuit, an ultrasonic transducer driving device and an ultrasonic transducer, so as to solve the oscillation problem caused by drain voltage coupling due to weak gate driving capability when the power tube is switching in the existing transformer driving circuit, and ensure the stability of the output signal during the switching process of the power tube.

[0006] To achieve the above-mentioned object of the invention, on the one hand, the present invention provides a driving circuit for a transformer, wherein the transformer includes a primary port, and the driving circuit includes:

[0007] A power tube having a first end, a second end, and a control end, wherein the first end is coupled to the primary port and the second end is grounded. The power tube is turned on and off to drive the transformer.

[0008] The first operational amplifier has a first input terminal and an output terminal, wherein the output terminal is coupled to the control terminal of the power tube.

[0009] A first current source has an input terminal and an output terminal, wherein the input terminal is connected to the supply voltage, and the output terminal is coupled to the first input terminal of the first operational amplifier.

[0010] A second current source has an input terminal and an output terminal, wherein the input terminal is coupled to the first input terminal of the first operational amplifier, and the output terminal is grounded.

[0011] The first switch has a first end and a second end, wherein the first end is connected to the power supply voltage and the second end is coupled to the control end of the power tube.

[0012] The second switch has a first end and a second end, wherein the first end is grounded and the second end is coupled to the control end of the power tube.

[0013] In the first state, the first current source outputs a first current, the first switch is turned on, so that the power tube is turned on.

[0014] In the second state, the second current source outputs a second current, and the second switch is turned on to turn off the power tube.

[0015] As a further improvement of the present application, when the driving circuit receives the first control signal, the driving circuit sequentially reaches the third state and the first state.

[0016] In the third state, the first current source outputs a third current until the voltage at the control end of the power tube is greater than a first preset voltage, and the third current is less than the first current.

[0017] As a further improvement of the present application, the driving circuit includes:

[0018] The second operational amplifier has a first input terminal, a second input terminal and an output terminal, wherein the first input terminal is connected to a first preset voltage, and the second input terminal is coupled to the control terminal of the power tube.

[0019] When the voltage at the control terminal of the power tube is less than the first preset voltage, the second operational amplifier outputs a first electrical signal, the first current source outputs a third current, and the drive circuit is in a third state.

[0020] When the voltage at the control end of the power tube is greater than the first preset voltage, the second operational amplifier outputs a second electrical signal, the first current source outputs a first current, and the drive circuit is in a first state.

[0021] As a further improvement of the present application, when the driving circuit receives the second control signal, the driving circuit sequentially reaches the second state and the fourth state.

[0022] In a fourth state, the second current source outputs a fourth current, and the fourth current is smaller than the second current.

[0023] As a further improvement of the present application, the driving circuit includes:

[0024] The first switch tube has a first terminal, a second terminal and a control terminal, wherein the control terminal is coupled to the first input terminal of the first operational amplifier and the second terminal is grounded.

[0025] The second switch tube has a first terminal, a second terminal and a control terminal, wherein the second terminal is connected to the power supply voltage and the control terminal is coupled to the first terminal of the first switch tube.

[0026] A third current source has an input terminal and an output terminal, wherein the input terminal is connected to the supply voltage, and the output terminal is coupled to the first terminal of the first switch tube.

[0027] a fourth current source having an input end and an output end, wherein the input end is coupled to the first end of the second switch tube, and the output end is grounded;

[0028] The third operational amplifier has a first input terminal, a second input terminal and an output terminal, wherein the first input terminal is coupled to the first terminal of the second switch tube, and the second input terminal is connected to a fourth preset voltage.

[0029] When the voltage at the first end of the second switch tube is greater than the fourth preset voltage, the third operational amplifier outputs a third electrical signal, the second current source outputs a second current, and the driving circuit is in the second state.

[0030] When the voltage at the first end of the second switch tube is less than the fourth preset voltage, the third operational amplifier outputs a fourth electrical signal, the second current source outputs a fourth current, and the drive circuit is in a fourth state.

[0031] As a further improvement of the present application, the first operational amplifier has a second input terminal, and the output terminal of the first operational amplifier is coupled to the second input terminal thereof.

[0032] The driving circuit further includes:

[0033] The first switch tube has a first terminal, a second terminal and a control terminal, wherein the control terminal is coupled to the first input terminal of the first operational amplifier and the second terminal is grounded.

[0034] The capacitor element has a first end and a second end, wherein the first end is coupled to the control end of the first switch tube, and the second end is coupled to the first end of the first switch tube.

[0035] In the second state, the second current source outputs a second current, and the voltage of the first input terminal of the first operational amplifier drops to a second preset voltage and then remains there until the difference between the voltage of the control terminal of the power tube and the voltage of the first input terminal of the first operational amplifier drops to a third preset voltage.

[0036] The second preset voltage corresponds to the voltage of the control terminal of the first switching tube in the Miller plateau period.

[0037] As a further improvement of the present application, the driving circuit includes:

[0038] The second switch tube has a first terminal, a second terminal and a control terminal, wherein the second terminal is connected to the power supply voltage and the control terminal is coupled to the first terminal of the first switch tube.

[0039] A third current source has an input terminal and an output terminal, wherein the input terminal is connected to the supply voltage, and the output terminal is coupled to the first terminal of the first switch tube.

[0040] a fourth current source having an input end and an output end, wherein the input end is coupled to the first end of the second switch tube, and the output end is grounded;

[0041] The third operational amplifier has a first input terminal, a second input terminal and an output terminal, wherein the first input terminal is coupled to the first terminal of the second switch tube, and the second input terminal is connected to a fourth preset voltage.

[0042] a fourth operational amplifier having a first input terminal, a second input terminal, and an output terminal, wherein the first input terminal is coupled to the control terminal of the power tube, and the second input terminal is coupled to the first input terminal of the first operational amplifier;

[0043] When the voltage at the first end of the second switch tube is greater than the fourth preset voltage, the third operational amplifier outputs a third electrical signal, the second current source outputs a second current, and the drive circuit is in a second state.

[0044] When the voltage at the first end of the second switching tube is less than the fourth preset voltage, the third operational amplifier outputs a fifth electrical signal, and the second current source stops outputting until the difference between the voltage at the control end of the power tube and the voltage at the first input end of the first operational amplifier is less than the third preset voltage, the fourth operational amplifier outputs a sixth electrical signal, controls the second current source to output a fourth current, and the drive circuit is in a fourth state.

[0045] As a further improvement of the present application, the fourth operational amplifier has a bias voltage whose value is equal to the third preset voltage.

[0046] As a further improvement of the present application, the second switch includes:

[0047] The third switch tube has a first end, a second end and a control end, wherein the first end is grounded, the second end is coupled to the control end of the power tube, and the control end is coupled to the first input end of the first operational amplifier.

[0048] On the other hand, the present application provides a driving device for an ultrasonic transducer, wherein the ultrasonic transducer includes a transducer element, and the driving device includes:

[0049] The transformer has a primary winding and a secondary winding, wherein the secondary winding is used to couple the transducer element, and the primary winding has a first primary port and a second primary port.

[0050] The first driving circuit, configured according to any of the above aspects, includes a first power tube, a first end of the first power tube is coupled to the first primary port, and a second end of the first power tube is grounded.

[0051] The second driving circuit, configured according to any of the above aspects, includes a second power tube, a first end of the second power tube is coupled to the second primary port, and a second end of the second power tube is grounded.

[0052] The first power tube and the second power tube are alternately turned on to drive the ultrasonic transducer.

[0053] As a further improvement of the present application, the driving device includes:

[0054] The driving power supply has an input terminal and an output terminal, wherein the input terminal is connected to the power supply voltage.

[0055] The primary winding further has a center tap end, and the center tap end is coupled to the output end of the driving power supply.

[0056] As a further improvement of the present application, the driving power supply includes:

[0057] An adjustable current source having an input terminal and an output terminal, wherein the output terminal is grounded.

[0058] The first transistor has a first terminal and a control terminal, wherein the control terminal is coupled to the first terminal, and the first terminal is coupled to the input terminal of the adjustable current source.

[0059] A second transistor has a first terminal and a control terminal, wherein the first terminal is coupled to the center tap terminal.

[0060] The impedance element has a first end and a second end, wherein the first end is coupled to the control end of the second transistor, and the second end is coupled to the control end of the first transistor.

[0061] As a further improvement of the present application, the impedance element is a resistor.

[0062] As a further improvement of the present application, the impedance element is a field effect transistor, and the impedance element further has a control end, and the control end is connected to the power supply voltage.

[0063] In another aspect, the present application provides an ultrasonic transducer, comprising:

[0064] Transducer element,

[0065] In the driving device described in any one of the above aspects, the secondary winding of the transformer in the driving device is coupled to the transducer element.

[0066] As a further improvement of the present application, the ultrasonic transducer further includes: a filter capacitor, and / or a voltage divider impedance.

[0067] Compared with the related art, the present invention has the following beneficial effects:

[0068] In the embodiments of the present application, the feedback loop of the operational amplifier, along with the control of the dual current sources and dual switches, achieves strong drive control during the power tube's on and off processes, thereby enabling rapid on / off switching of the power tube. Furthermore, the current source, switch, and first operational amplifier work together to precisely regulate the voltage at the control terminal of the power tube, ensuring stability during rapid on-state switching and reducing the risk of false triggering during rapid off-state switching. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] Figure 1 A structural diagram of a transformer driving circuit provided in an exemplary embodiment of the present application is shown;

[0070] Figure 2 A waveform diagram showing a conduction process of a power tube in a driving circuit provided by an exemplary embodiment of the present application is shown;

[0071] Figure 3 A waveform diagram showing a power tube shut-down process in a driving circuit provided by an exemplary embodiment of the present application is shown;

[0072] Figure 4 A schematic diagram of an ultrasonic transducer and a driving device thereof provided in an exemplary embodiment of the present application is shown;

[0073] Figure 5 A schematic diagram of an ultrasonic transducer and a driving device thereof provided in another exemplary embodiment of the present application is shown;

[0074] Figure 6 A schematic structural diagram of a driving power supply provided by an exemplary embodiment of the present application is shown;

[0075] Figure 7 A schematic structural diagram of a driving power supply provided in another exemplary embodiment of the present application is shown. DETAILED DESCRIPTION

[0076] The present invention will be described in detail below with reference to the specific embodiments shown in the accompanying drawings. However, these embodiments do not limit the present invention, and any structural, methodological, or functional changes made by those skilled in the art based on these embodiments are all within the scope of protection of the present invention.

[0077] It should be noted that the term "comprises" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In addition, the terms "first," "second," etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance.

[0078] Figure 1 FIG2 shows a structural diagram of a driving circuit 100 of a transformer 500 provided in an exemplary embodiment of the present application.

[0079] The driving circuit 100 is used to drive a transformer 500. The transformer 500 includes a primary port.

[0080] The driving circuit 100 includes a power transistor 110 , a first operational amplifier 121 , a first current source 122 , a second current source 123 , a first switch 124 , and a second switch 125 .

[0081] The power tube 110 has a first terminal, a second terminal, and a control terminal. The first terminal of the power tube 110 is coupled to the primary port; the second terminal of the power tube 110 is grounded.

[0082] The power tube 110 is turned on and off to drive the transformer 500 .

[0083] The first operational amplifier 121 has a first input terminal and an output terminal. The output terminal of the first operational amplifier 121 is coupled to the control terminal of the power transistor 110 .

[0084] The first current source 122 has an input terminal and an output terminal. The input terminal of the first current source 122 is connected to the power supply voltage VDD; and the output terminal of the first current source 122 is coupled to the first input terminal of the first operational amplifier 121 .

[0085] It should be noted that the supply voltage VDD in this embodiment is an exemplary representation, used only to refer to the power supply terminal of the driver circuit 100, and does not limit the type of supply voltage for the driver circuit 100. In actual applications, those skilled in the art should adopt an appropriate supply voltage based on the power supply requirements of the actual application scenario, such as the voltage of the access circuit (usually represented by VCC). This does not limit the application scenarios of this solution.

[0086] The second current source 123 has an input terminal and an output terminal. The input terminal of the second current source 123 is coupled to the first input terminal of the first operational amplifier 121 ; and the output terminal of the second current source 123 is grounded.

[0087] The first switch 124 has a first terminal and a second terminal. The first terminal of the first switch 124 is connected to the power supply voltage VDD, and the second terminal of the first switch 124 is coupled to the control terminal of the power tube 110.

[0088] The second switch 125 has a first terminal and a second terminal. The first terminal of the second switch 125 is grounded, and the second terminal of the second switch 125 is coupled to the control terminal of the power tube 110 .

[0089] In the first state, the first current source 122 outputs the first current, the first switch 124 is turned on, so that the power tube 110 is turned on; in the second state, the second current source 123 outputs the second current, the second switch 125 is turned on, so that the power tube 110 is turned off.

[0090] In summary, in the embodiments of the present application, strong drive control is achieved during the on / off process of the power tube 110 through the feedback loop of the operational amplifier, the dual current sources, and the dual switches, thereby enabling rapid on / off switching of the power tube 110. Furthermore, the current source, the switch, and the first operational amplifier cooperate to precisely adjust the voltage at the control terminal of the power tube 110, ensuring stability during rapid on-state switching and reducing the risk of false triggering during rapid off-state switching.

[0091] In the first state, the current output by the first current source 122 is input to the first input terminal of the first operational amplifier 121. After being amplified by the first operational amplifier 121, the current output by the first operational amplifier 121 is input to the control terminal of the power transistor 110. Simultaneously, the first switch 124 is turned on, rapidly pulling up the voltage Vg at the control terminal of the power transistor 110, thereby increasing the conduction speed of the power transistor 110 while also ensuring conduction stability.

[0092] In the second state, the output terminal of the second current source 123 is grounded, and the voltage Vm_in of the first input terminal of the first operational amplifier 121 decreases. During this process, the voltage Vg of the control terminal of the power tube 110 decreases accordingly. At this time, the second switch 125 is turned on, and the first terminal of the second switch 125 is grounded, so that the voltage Vg of the control terminal of the power tube 110 is quickly pulled down.

[0093] In one embodiment, the power transistor 110 is a field-effect transistor. During the process of rapidly pulling down the voltage Vg at the control terminal of the power transistor 110, the Miller current within the power transistor 110 is rapidly bypassed to ground and prevented from flowing into the gate capacitor. Furthermore, the second current source 123 cooperates to continuously pull down the voltage Vg at the control terminal of the power transistor 110, ensuring that the voltage Vg at the control terminal of the power transistor 110 is clamped near 0V. This prevents mis-turning on the power transistor 110 due to the Miller current while rapidly shutting down the power transistor 110.

[0094] In one embodiment, the power transistor 110 may be a field effect transistor, wherein the first terminal of the power transistor 110 may be a drain of the field effect transistor, the second terminal of the power transistor 110 may be a source of the field effect transistor, and the control terminal of the power transistor 110 may be a gate of the field effect transistor.

[0095] In one embodiment, the first input terminal of the first operational amplifier 121 may be a non-inverting input terminal.

[0096] In one embodiment, the first operational amplifier 121 further has a second input terminal, and the second input terminal of the first operational amplifier 121 may be an inverting input terminal.

[0097] In one embodiment, the second input terminal of the first operational amplifier 121 is coupled to the output terminal of the first operational amplifier 121. In this way, negative feedback is achieved.

[0098] In one embodiment, the first current source 122 and the second current source 123 are controlled current sources, which are driven by electrical signals to adjust their output currents.

[0099] In one embodiment, the second switch 125 may be a semiconductor electronic switch. Figure 1 The second switch 125 includes a third switch transistor having a first terminal, a second terminal, and a control terminal. The first terminal of the third switch transistor is grounded; the second terminal of the third switch transistor is coupled to the control terminal of the power transistor 110; and the control terminal of the third switch transistor is coupled to the first input terminal of the first operational amplifier 121.

[0100] Using the third switch tube as the second switch 125 is beneficial to improving the switching speed and reducing the conduction loss and switching loss.

[0101] In one embodiment, the third switch is a field-effect transistor, a triode, or the like. For example, the third switch is a field-effect transistor. The first terminal of the third switch may be a drain terminal connected to ground; the second terminal of the third switch may be a source terminal coupled to the control terminal of the power transistor 110; and the control terminal of the third switch may be a gate terminal coupled to the first input terminal of the first operational amplifier 121.

[0102] In the process of the driving circuit 100 driving the transformer 500 , the on / off state of the power tube 110 in the driving circuit 100 determines the energy transfer at the primary port of the transformer 500 .

[0103] In a possible implementation, when the driving circuit 100 receives the first control signal, the driving circuit 100 sequentially reaches the third state and the first state.

[0104] In the third state, the first current source 122 outputs a third current until the voltage Vg at the control terminal of the power tube 110 is greater than the first preset voltage VDD / 2, and the third current is less than the first current.

[0105] In the embodiment of the present application, during the process of driving the power tube 110 to conduct, the voltage Vg at the control end of the power tube 110 is controlled to slowly and steadily rise to the first preset voltage VDD / 2 through the small current output in the third state, and then the large current output is switched to eliminate the overshoot risk of the control end of the power tube 110, while shortening the Miller platform time and reducing the conduction loss.

[0106] In one embodiment, the first control signal is a high level signal.

[0107] In one embodiment, when the first current source 122 outputs the third current, the control terminal capacitor inside the power tube 110 is slowly charged with a smaller current value, thereby preventing the power tube 110 from instantaneously overcurrenting.

[0108] In one embodiment, the driving circuit 100 further includes a second operational amplifier 126 .

[0109] The second operational amplifier 126 has a first input terminal, a second input terminal, and an output terminal. The first input terminal of the second operational amplifier 126 is connected to the first preset voltage VDD / 2. The second input terminal of the second operational amplifier 126 is coupled to the control terminal of the power tube 110 .

[0110] When the voltage Vg at the control terminal of the power tube 110 is less than the first preset voltage VDD / 2, the second operational amplifier 126 outputs the first electrical signal, the first current source 122 outputs the third current, and the driving circuit 100 is in the third state.

[0111] When the voltage Vg at the control terminal of the power tube 110 is greater than the first preset voltage VDD / 2, the second operational amplifier 126 outputs the second electrical signal, the first current source 122 outputs the first current, and the driving circuit 100 is in the first state.

[0112] When the voltage Vg at the control terminal of the power tube 110 is equal to the first preset voltage VDD / 2, the second operational amplifier 126 outputs the first electrical signal, the first current source 122 outputs the third current, and the driving circuit 100 is in the third state.

[0113] In one embodiment, in the third state, the first current source 122 outputs a low current (the third current) and slowly pulls up the voltage Vg at the control terminal of the power transistor 110. When the voltage Vg at the control terminal of the power transistor 110 exceeds the first preset voltage VDD / 2, the second operational amplifier 126 outputs a low level signal, the first current source 122 receives the high level signal, and outputs a high current (the first current), and the driver circuit 100 enters the first state.

[0114] In the embodiment of the present application, the second operational amplifier 126 accurately detects whether the voltage Vg of the control terminal of the control power tube 110 has slowly risen to the first preset voltage VDD / 2, which is conducive to accurately controlling the transition from the third state to the first state, thereby ensuring that the overshoot risk of the control terminal of the power tube 110 is eliminated.

[0115] It should be noted that the present embodiment only uses the first preset voltage of VDD / 2 as an example to illustrate the state switching condition of the driver circuit 100, and does not limit the value of the first preset voltage. Those skilled in the art should be able to determine the value of the first preset voltage based on the parameters of various components in actual application scenarios.

[0116] In one embodiment, the second operational amplifier 126 may be a comparator. The first input terminal of the second operational amplifier 126 may be the positive input terminal of the comparator, and the second input terminal of the second operational amplifier 126 may be the negative input terminal of the comparator. When the voltage at the positive input terminal of the comparator is higher than the voltage at the negative input terminal, the comparator outputs a high-level signal, and vice versa, the comparator outputs a low-level signal.

[0117] In one possible implementation, when the voltage Vg at the control terminal of the power transistor 110 is less than the first preset voltage VDD / 2, the second operational amplifier 126 outputs a high-level signal. The first current source 122 receives the high-level signal and outputs a third current, and the driving circuit 100 enters the third state.

[0118] In some embodiments, when the driving circuit 100 receives the second control signal, the driving circuit 100 sequentially reaches the second state and the fourth state.

[0119] In the fourth state, the second current source 123 outputs a fourth current, which is smaller than the second current.

[0120] In the embodiment of the present application, by switching between the second state and the fourth state, the turn-off efficiency of the power tube 110 is improved while the stability of the driving circuit 100 is optimized.

[0121] In one embodiment, the second control signal is a low level signal.

[0122] In the fourth state, the second current source 123 outputs a fourth current, slowly pulling down the voltage Vm_in of the first input terminal of the first operational amplifier 121, so that the voltage Vm_in of the first input terminal of the first operational amplifier 121 drops to zero potential, and the voltage Vg of the control terminal of the power tube 110 drops synchronously with the voltage Vm_in of the first input terminal of the first operational amplifier 121 until it stabilizes to 0 potential.

[0123] Please refer to Figure 1In one embodiment, the driving circuit 100 further includes a first switch 127. The first switch 127 has a first terminal, a second terminal, and a control terminal. The control terminal of the first switch 127 is coupled to the first input terminal of the first operational amplifier 121; the second terminal of the first switch 127 is grounded.

[0124] In one embodiment, the driving circuit 100 further includes a second switch 129 . The second switch 129 has a first terminal, a second terminal, and a control terminal. The second terminal of the second switch 129 is connected to the power supply voltage VDD; the control terminal of the second switch 129 is coupled to the first terminal of the first switch 127 .

[0125] In one embodiment, the driving circuit 100 further includes a third current source 1210 . The third current source 1210 has an input terminal and an output terminal. The input terminal of the third current source 1210 is connected to the supply voltage VDD, and the output terminal of the third current source 1210 is coupled to the first terminal of the first switch 127 .

[0126] In one embodiment, the driving circuit 100 further includes a fourth current source 1213. The fourth current source 1213 has an input terminal and an output terminal. The input terminal of the fourth current source 1213 is coupled to the first terminal of the second switch 129, and the output terminal of the fourth current source 1213 is grounded.

[0127] In one embodiment, the driver circuit 100 further includes a third operational amplifier 1211. The third operational amplifier 1211 has a first input terminal, a second input terminal, and an output terminal. A first terminal of the third operational amplifier 1211 is coupled to the first terminal of the second switch 129; a second terminal of the third operational amplifier 1211 is connected to a fourth preset voltage Vn.

[0128] When the voltage Vd at the first end of the second switch tube 129 is greater than the fourth preset voltage Vn, the third operational amplifier 1211 outputs a third electrical signal, the second current source 123 outputs a second current, and the driving circuit 100 is in the second state.

[0129] When the voltage Vd at the first end of the second switch tube 129 is less than the fourth preset voltage Vn, the third operational amplifier 1211 outputs a fourth electrical signal, the second current source 123 outputs a fourth current, and the driving circuit 100 is in the fourth state.

[0130] In the embodiment of the present application, the third operational amplifier 1211 detects the relationship between the voltage Vd at the first end of the second switch tube 129 and the fourth preset voltage Vn, thereby accurately determining whether the drive circuit 100 should be switched from the second state to the fourth state, thereby ensuring that the drive circuit 100 improves the shutdown efficiency of the power tube 110 while optimizing the stability of the drive circuit 100.

[0131] When the driving circuit 100 is in the second state, the second current source 123 outputs the second current, and the voltage Vm_in of the first input terminal of the first operational amplifier 121 drops rapidly, that is, the voltage of the control terminal of the first switch tube 127 drops rapidly, and the first switch tube 127 is turned on.

[0132] As first switch 127 reaches the Miller plateau, its conduction capability gradually decreases. Because third current source 1210 has an input terminal connected to supply voltage VDD and an output terminal connected to the first terminal of first switch 127, as the conduction capability of first switch 127 decreases, the voltage at the first terminal of first switch 127 gradually increases under the influence of third current source 1210.

[0133] Furthermore, the voltage at the first end of the first switch tube 127 gradually increases, causing the conduction capability of the second switch tube 129 to decrease. The voltage Vd at the first end of the second switch tube 129 is affected by the fourth current source 1213 and gradually decreases.

[0134] Therefore, based on the change pattern of the voltage Vd at the first end of the second switch tube 129 when the driving circuit 100 is in the second state, the voltage Vm_in at the first input end of the first operational amplifier 121 can be indirectly determined by measuring the voltage Vd at the first end of the second switch tube 129, thereby determining whether it is necessary to control the driving circuit 100 to enter the next state.

[0135] When the voltage at the first terminal of the second switch 129 is greater than the fourth preset voltage Vn, it indicates that the first switch 127 has not entered the Miller plateau phase, and the drive circuit 100 is still in the second state. In the second state, the voltage Vm_in at the first input terminal of the first operational amplifier 121 gradually decreases until the voltage Vd_comp at the output terminal of the third operational amplifier 1211 indicates that the voltage at the first terminal of the second switch 129 is less than the fourth preset voltage Vn. The second current source 123 outputs a smaller fourth current, thereby reducing the rate of decrease of the voltage Vg at the control terminal of the power transistor 110.

[0136] The second through fourth states of the driver circuit 100 are all circuit states during the shutdown process of the power transistor 110 in the driver circuit 100. In the second state, the second current source 123 outputs a relatively large second current, causing the voltage Vg at the control terminal of the power transistor 110 to decrease at a relatively large slope, providing a strong drive to shut down the power transistor 110. In the fourth state, the second current source 123 outputs a relatively small fourth current, slowly pulling down the voltage Vg at the control terminal of the power transistor 110, thereby reducing leakage inductance oscillations of the power transistor 110.

[0137] In one embodiment, the first operational amplifier 121 has a second input terminal, and an output terminal thereof is coupled to the second input terminal of the first operational amplifier 121 .

[0138] In one embodiment, the driving circuit 100 further includes a first switch 127. The first switch 127 has a first terminal, a second terminal, and a control terminal. The control terminal of the first switch 127 is coupled to the first input terminal of the first operational amplifier 121; and the second terminal of the first switch 127 is grounded.

[0139] In one embodiment, the driving circuit 100 further includes a capacitor 128. The capacitor 128 has a first end and a second end. The first end of the capacitor 128 is coupled to the control end of the first switching transistor 127; the second end of the capacitor 128 is coupled to the first end of the first switching transistor 127. In the second state, the second current source 123 outputs a second current, and the voltage Vm_in at the first input end of the first operational amplifier 121 drops to a second preset voltage and then remains there until the difference between the voltage Vg at the control end of the power transistor 110 and the voltage Vm_in at the first input end of the first operational amplifier 121 drops to a third preset voltage.

[0140] In one embodiment, the second preset voltage corresponds to the voltage at the control terminal of the first switch tube 127 when the first switch tube 127 is in the Miller plateau phase.

[0141] In the embodiment of the present application, by providing the first switch tube 127 and the capacitor element 128, a Miller platform is formed in the second state, thereby improving the shutdown speed of the power tube 110 during the shutdown process, while suppressing the false turn-on of the power tube 110 caused by the rebound of the voltage Vg at the control end of the power tube 110.

[0142] In the second state, the voltage at the control terminal of the first switching transistor 127 rapidly drops to a second preset voltage, corresponding to the Miller plateau voltage of the first switching transistor 127. At this point, the voltage at the control terminal of the first switching transistor 127 stabilizes at the second preset voltage, the second current source 123 charges the capacitor 128, and the voltage at the first terminal of the first switching transistor 127 drops. When the difference between the voltage Vg at the control terminal of the power transistor 110 and the voltage Vm_in at the first input terminal of the first operational amplifier 121 drops to a third preset voltage, the Miller plateau ends.

[0143] In one embodiment, the second preset voltage is higher than the turn-on voltage of the power tube 110 .

[0144] In one embodiment, the first switch 127 may be an N-channel MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor). The first terminal of the first switch 127 may be the drain of the N-channel MOSFET, and the control terminal of the first switch 127 may be the gate of the N-channel MOSFET.

[0145] In the second state, since the capacitor element 128 is connected between the gate and the drain of the first switch transistor 127, the capacitor element 128 acts as a Miller capacitor.

[0146] In one embodiment, the driving circuit 100 further includes a second switch 129 having a first terminal, a second terminal, and a control terminal. The second terminal of the second switch 129 is connected to the power supply voltage VDD, and the control terminal of the second switch 129 is coupled to the first terminal of the first switch 127.

[0147] In one embodiment, the driving circuit 100 further includes a third current source 1210 . The third current source 1210 has an input terminal and an output terminal. The input terminal of the third current source 1210 is connected to the supply voltage VDD; the output terminal of the third current source 1210 is coupled to the first terminal of the first switch 127 .

[0148] In one embodiment, the driving circuit 100 further includes a fourth current source 1213. The fourth current source 1213 has an input terminal and an output terminal. The input terminal of the fourth current source 1213 is coupled to the first terminal of the second switch 129; and the output terminal of the fourth current source 1213 is grounded.

[0149] In one embodiment, the driver circuit 100 further includes a third operational amplifier 1211. The third operational amplifier 1211 has a first input terminal, a second input terminal, and an output terminal. The first input terminal of the third operational amplifier 1211 is coupled to the first terminal of the second switch 129; the second input terminal of the third operational amplifier 1211 is connected to a fourth preset voltage Vn.

[0150] In one embodiment, the driver circuit 100 further includes a fourth operational amplifier 1212. The fourth operational amplifier 1212 has a first input terminal, a second input terminal, and an output terminal. The first input terminal of the fourth operational amplifier 1212 is coupled to the control terminal of the power transistor 110; the second input terminal of the fourth operational amplifier 1212 is coupled to the first input terminal of the first operational amplifier 121.

[0151] In one embodiment, the fourth operational amplifier 1212 has a bias voltage equal to a third predetermined voltage.

[0152] Using a fourth operational amplifier 1212 with a bias voltage equal to the third preset voltage facilitates accurate detection of the difference between the voltage Vg at the control terminal of the power transistor 110 and the voltage Vm_in at the first input terminal of the first operational amplifier 121, thereby determining the end of the Miller plateau. Furthermore, using the fourth operational amplifier 1212 with a bias voltage facilitates eliminating critical oscillations and improving stability.

[0153] When the voltage Vd at the first end of the second switch tube 129 is greater than the fourth preset voltage Vn, the third operational amplifier 1211 outputs a third electrical signal, the second current source 123 outputs a second current, and the driving circuit 100 is in the second state.

[0154] When the voltage Vd at the first end of the second switch tube 129 is equal to the fourth preset voltage Vn, the third operational amplifier 1211 outputs a third electrical signal, the second current source 123 outputs a second current, and the driving circuit 100 is in the second state.

[0155] When the voltage Vd at the first terminal of the second switch tube 129 is less than the fourth preset voltage Vn, the third operational amplifier 1211 outputs a fifth electrical signal, and the second current source 123 stops outputting. This continues until the difference between the voltage Vg at the control terminal of the power tube 110 and the voltage Vm_in at the first input terminal of the first operational amplifier 121 is less than the third preset voltage. The fourth operational amplifier 1212 outputs a sixth electrical signal Vm_comp2 to control the second current source 123 to output a fourth current, and the driving circuit 100 is in the fourth state.

[0156] In the embodiment of the present application, when the first switch tube 127 reaches the Miller plateau, the second current source 123 is first controlled to suspend output, so that the voltage Vg at the control terminal of the power tube 110 slowly approaches the voltage Vm_in at the first input terminal of the first operational amplifier 121. This allows the driver circuit 100 to take both speed and circuit stability into consideration during the shutdown process, further preventing the power tube 110 from being mis-turned on.

[0157] After the first switch tube 127 reaches the Miller plateau, the second current source 123 is controlled to temporarily stop outputting, and the voltage Vg at the control terminal of the power tube 110 converges to the voltage Vm_in at the first input terminal of the first operational amplifier 121 by relying on the loop of the first operational amplifier 121.

[0158] In one embodiment, the first input terminal of the third operational amplifier 1211 may be a positive input terminal, and the second input terminal of the third operational amplifier 1211 may be an inverting input terminal. Then the fifth electrical signal is a low-level signal.

[0159] In one embodiment, the first input terminal of the fourth operational amplifier 1212 may be a positive input terminal, and the second input terminal of the fourth operational amplifier 1212 may be a negative input terminal. Then, the sixth electrical signal Vm_comp2 is a low-level signal.

[0160] Please refer to Figure 2 , which shows a waveform diagram of the conduction process of the power tube 110 in the driving circuit 100 provided in an exemplary embodiment of the present application.

[0161] When the first control signal ctl1 changes from a low level (0V) to a high level (5V), the driving circuit 100 enters the third state.

[0162] In the third state, the voltage Vg at the control terminal of the power transistor 110 and the voltage Vm_in at the first input terminal of the first operational amplifier 121 slowly increase. When the voltage Vg_comp at the output terminal of the second operational amplifier 126 changes from a high level (5V) to a low level (0V), it indicates that the voltage Vg at the control terminal of the power transistor 110 is greater than the first preset voltage VDD / 2, and the driver circuit 100 enters the first state.

[0163] Please refer to Figure 3 , which shows a waveform diagram of the shutdown process of the power tube 110 in the driving circuit 100 provided in an exemplary embodiment of the present application. When the second current source 123 stops outputting, the driving circuit 100 is in the fifth state.

[0164] When the driver circuit 100 receives the second control signal ctl2 and switches from a high level (5V) to a low level (0V), it enters the second state. In the second state, the voltage Vm_in at the first input terminal of the first operational amplifier 121 drops rapidly, and the voltage Vg at the control terminal of the power transistor 110 drops. The rate of decrease of the voltage Vg at the control terminal of the power transistor 110 is slower than the rate of decrease of the voltage Vm_in at the first input terminal of the first operational amplifier 121.

[0165] The third operational amplifier 1211 detects the voltage Vd at the first terminal of the second switching transistor 129 to determine whether the first switching transistor 127 has reached the Miller plateau. When the voltage Vd at the first terminal of the second switching transistor 129 is less than the fourth preset voltage Vn, the driving circuit 100 enters the fifth state. In the fifth state, the second current source 123 stops outputting current, and the voltage Vm_in at the first input terminal of the first operational amplifier 121 remains constant.

[0166] The loop formed by the first operational amplifier 121 pulls down the voltage Vg at the control terminal of the power transistor 110 until the voltage difference between the voltage Vg at the control terminal of the power transistor 110 and the first operational amplifier 121 exceeds a third predetermined voltage. At this point, the fourth state is entered, and the second current source 123 is controlled to output a fourth current, slowly pulling down the voltage Vg at the control terminal of the power transistor 110 until the voltage Vg at the control terminal of the power transistor 110 approaches zero.

[0167] When the power tube 110 is turned off, the voltage Vg at the control terminal of the power tube 110 gradually decreases until the voltage Vg at the control terminal of the power tube 110 is lower than the first preset voltage VDD / 2, and the voltage Vg_comp at the output terminal of the second operational amplifier 126 outputs a low level.

[0168] Please refer to Figure 4 , which shows a schematic diagram of an ultrasonic transducer 400 and its driving device 10 provided in an exemplary embodiment of the present application. The ultrasonic transducer 400 includes a transducer element 410, and the driving device 10 includes a transformer 500, a first driving circuit 200, and a second driving circuit 300.

[0169] The transformer 500 has a primary winding and a secondary winding. The secondary winding of the transformer 500 is used to couple to the transducer element 410. The primary winding of the transformer 500 has a first primary port and a second primary port.

[0170] The first driving circuit 200 is configured according to the driving circuit 100 provided in any of the above embodiments.

[0171] The first driving circuit 200 includes a first power transistor 210. A first terminal of the first power transistor 210 is coupled to the first primary port, and a second terminal of the first power transistor 210 is grounded.

[0172] The second driving circuit 300 is configured according to the driving circuit 100 provided in any of the above embodiments.

[0173] The second driving circuit 300 includes a second power tube 310. A first terminal of the second power tube 310 is coupled to the second primary port, and a second terminal of the second power tube 310 is grounded.

[0174] The first power tube 210 and the second power tube 310 are alternately turned on to drive the ultrasonic transducer 400 .

[0175] In an embodiment of the present application, the primary winding is alternately driven by the first drive circuit 200 and the second drive circuit 300, and the drive circuit 100 provided by any of the above embodiments is configured with the first drive circuit 200 and the second drive circuit 300, thereby providing a strong driving capability, effectively reducing conduction and switching losses, improving the driving efficiency of the drive device 10, and improving the transduction effect of the ultrasonic transducer 400.

[0176] In one embodiment, the ultrasonic transducer 400 further includes a filter capacitor 420. The filter capacitor 420 is coupled to the secondary winding of the transformer 500. The filter capacitor 420 is used to filter out the AC component in the pulsed DC power, making the output voltage smoother.

[0177] In one embodiment, the ultrasonic transducer 400 further includes a voltage divider impedance 430 . The voltage divider impedance 430 is coupled to the secondary winding of the transformer 500 . The voltage divider impedance 430 is used to limit current and divide voltage, thereby protecting the transducer element 410 .

[0178] In one embodiment, please refer to Figure 4The ultrasonic transducer 400 further includes a filter capacitor 420 and a voltage divider impedance 430. The filter capacitor 420 and the voltage divider impedance 430 are combined to provide resistance to power supply fluctuations. The voltage divider impedance 430 reduces the impact of power supply voltage fluctuations on the transducer element 410, and the filter capacitor 420 is used to smooth power supply voltage fluctuations.

[0179] In one embodiment, the first driving circuit 200 and the second driving circuit 300 are configured as follows.

[0180] The first driving circuit 200 includes a first power transistor 210 , a fifth operational amplifier 221 , a fifth current source 222 , a sixth current source 223 , a third switch 224 , and a fourth switch 225 .

[0181] The first power tube 210 has a first terminal, a second terminal, and a control terminal. The first terminal of the first power tube 210 is coupled to the primary port; the second terminal of the first power tube 210 is grounded. The first power tube 210 is turned on and off to drive the transformer 500.

[0182] The fifth operational amplifier 221 has a first input terminal and an output terminal. The output terminal of the fifth operational amplifier 221 is coupled to the control terminal of the first power transistor 210 .

[0183] The fifth current source 222 has an input terminal and an output terminal. The input terminal of the fifth current source 222 is connected to the supply voltage VDD; and the output terminal of the fifth current source 222 is coupled to the first input terminal of the fifth operational amplifier 221 .

[0184] The sixth current source 223 has an input terminal and an output terminal. The input terminal of the sixth current source 223 is coupled to the first input terminal of the fifth operational amplifier 221 ; and the output terminal of the sixth current source 223 is grounded.

[0185] The third switch 224 has a first terminal and a second terminal. The first terminal of the third switch 224 is connected to the power supply voltage VDD; and the second terminal of the third switch 224 is coupled to the control terminal of the power transistor 110 .

[0186] The fourth switch 225 has a first terminal and a second terminal. The first terminal of the fourth switch 225 is grounded, and the second terminal of the fourth switch 225 is coupled to the control terminal of the first power transistor 210 .

[0187] The second driving circuit 300 includes a second power transistor 310 , a ninth operational amplifier 321 , a ninth current source 322 , a tenth current source 323 , a fifth switch 324 , and a sixth switch 325 .

[0188] The second power tube 310 has a first terminal, a second terminal and a control terminal. The first terminal of the second power tube 310 is coupled to the primary port; the second terminal of the second power tube 310 is grounded. The second power tube 310 is turned on and off to drive the transformer 500.

[0189] The ninth operational amplifier 321 has a first input terminal and an output terminal. The output terminal of the ninth operational amplifier 321 is coupled to the control terminal of the second power transistor 310 .

[0190] The ninth current source 322 has an input terminal and an output terminal. The input terminal of the ninth current source 322 is connected to the supply voltage VDD; and the output terminal of the ninth current source 322 is coupled to the first input terminal of the ninth operational amplifier 321 .

[0191] The tenth current source 323 has an input terminal and an output terminal. The input terminal of the tenth current source 323 is coupled to the first input terminal of the ninth operational amplifier 321 ; and the output terminal of the tenth current source 323 is grounded.

[0192] The fifth switch 324 has a first terminal and a second terminal. The first terminal of the fifth switch 324 is connected to the power supply voltage VDD; the second terminal of the fifth switch 324 is coupled to the control terminal of the second power transistor 310 .

[0193] The sixth switch 325 has a first terminal and a second terminal. The first terminal of the sixth switch 325 is grounded, and the second terminal of the sixth switch 325 is coupled to the control terminal of the second power transistor 310 .

[0194] In one embodiment, the first driving circuit 200 and the second driving circuit 300 may be configured according to the driving circuit 100 provided in other embodiments described above.

[0195] Please refer to Figure 5 , which shows a schematic diagram of an ultrasonic transducer 400 and a driving device 10 thereof provided in another exemplary embodiment of the present application, which further shows the structure of the first driving circuit 200 and further shows the structure of the second driving circuit 300.

[0196] Please refer to Figure 4 The first driving circuit 200 includes a first power tube 210, a fifth operational amplifier 221, a fifth current source 222, a sixth current source 223, a third switch 224, a fourth switch 225, a sixth operational amplifier 226, a fourth switch tube 227, a first capacitor element 228, a fifth switch tube 229, a seventh current source 2210, an eighth current source 2213, a seventh operational amplifier 2211, and an eighth operational amplifier 2212.

[0197] The first power tube 210 has a first terminal, a second terminal, and a control terminal. The first terminal of the first power tube 210 is coupled to the primary port; the second terminal of the first power tube 210 is grounded. The first power tube 210 is turned on and off to drive the transformer 500.

[0198] The fifth operational amplifier 221 has a first input terminal and an output terminal. The output terminal of the fifth operational amplifier 221 is coupled to the control terminal of the first power transistor 210 .

[0199] The fifth current source 222 has an input terminal and an output terminal. The input terminal of the fifth current source 222 is connected to the supply voltage VDD; and the output terminal of the fifth current source 222 is coupled to the first input terminal of the fifth operational amplifier 221 .

[0200] The sixth current source 223 has an input terminal and an output terminal. The input terminal of the sixth current source 223 is coupled to the first input terminal of the fifth operational amplifier 221 ; and the output terminal of the sixth current source 223 is grounded.

[0201] The third switch 224 has a first terminal and a second terminal. The first terminal of the third switch 224 is connected to the power supply voltage VDD; and the second terminal of the third switch 224 is coupled to the control terminal of the power transistor 110 .

[0202] The fourth switch 225 has a first terminal and a second terminal. The first terminal of the fourth switch 225 is grounded, and the second terminal of the fourth switch 225 is coupled to the control terminal of the first power transistor 210 .

[0203] The sixth operational amplifier 226 has a first input terminal, a second input terminal, and an output terminal. The first input terminal of the sixth operational amplifier 226 is connected to a first preset voltage, and the second input terminal of the sixth operational amplifier 226 is coupled to the control terminal of the first power transistor 210 .

[0204] The fourth switch tube 227 has a first terminal, a second terminal and a control terminal. The control terminal of the fourth switch tube 227 is coupled to the first input terminal of the fifth operational amplifier 221; and the second terminal of the fourth switch tube 227 is grounded.

[0205] The first capacitor 228 has a first terminal and a second terminal. The first terminal of the first capacitor 228 is coupled to the control terminal of the fourth switch 227 ; the second terminal of the first capacitor 228 is coupled to the first terminal of the fourth switch 227 .

[0206] The fifth switch 229 has a second terminal and a control terminal. The second terminal of the fifth switch 229 is connected to the power supply voltage VDD; and the control terminal of the fifth switch 229 is coupled to the first terminal of the fourth switch 227.

[0207] The seventh current source 2210 has an input terminal and an output terminal. The input terminal of the seventh current source 2210 is connected to the power supply voltage VDD; and the output terminal of the seventh current source 2210 is coupled to the first terminal of the fourth switch 227 .

[0208] The eighth current source 2213 has an input terminal and an output terminal. The input terminal of the eighth current source 2213 is coupled to the first terminal of the fifth switch 229 ; and the output terminal of the eighth current source 2213 is grounded.

[0209] The seventh operational amplifier 2211 has a first input terminal, a second input terminal and an output terminal. The first input terminal of the seventh operational amplifier 2211 is coupled to the first terminal of the fifth switch 229 ; the second input terminal of the seventh operational amplifier 2211 is connected to the fourth preset voltage.

[0210] The eighth operational amplifier 2212 has a first input terminal, a second input terminal, and an output terminal. The first input terminal of the eighth operational amplifier 2212 is coupled to the control terminal of the first power transistor 210 ; the second input terminal of the eighth operational amplifier 2212 is coupled to the first input terminal of the fifth operational amplifier 221 .

[0211] The second driving circuit 300 includes a second power tube 310, a ninth operational amplifier 321, a ninth current source 322, a tenth current source 323, a fifth switch 324, a sixth switch 325, a tenth operational amplifier 326, a sixth switch tube 327, a second capacitor element 328, a seventh switch tube 329, an eleventh current source 3210, a twelfth current source 3213, an eleventh operational amplifier 3211, and a twelfth operational amplifier 3212.

[0212] The second power tube 310 has a first terminal, a second terminal and a control terminal. The first terminal of the second power tube 310 is coupled to the primary port; the second terminal of the second power tube 310 is grounded. The second power tube 310 is turned on and off to drive the transformer 500.

[0213] The ninth operational amplifier 321 has a first input terminal and an output terminal. The output terminal of the ninth operational amplifier 321 is coupled to the control terminal of the second power transistor 310 .

[0214] The ninth current source 322 has an input terminal and an output terminal. The input terminal of the ninth current source 322 is connected to the supply voltage VDD; and the output terminal of the ninth current source 322 is coupled to the first input terminal of the ninth operational amplifier 321 .

[0215] The tenth current source 323 has an input terminal and an output terminal. The input terminal of the tenth current source 323 is coupled to the first input terminal of the ninth operational amplifier 321 ; and the output terminal of the tenth current source 323 is grounded.

[0216] The fifth switch 324 has a first terminal and a second terminal. The first terminal of the fifth switch 324 is connected to the power supply voltage VDD; the second terminal of the fifth switch 324 is coupled to the control terminal of the second power transistor 310 .

[0217] The sixth switch 325 has a first terminal and a second terminal. The first terminal of the sixth switch 325 is grounded, and the second terminal of the sixth switch 325 is coupled to the control terminal of the second power transistor 310 .

[0218] The tenth operational amplifier 326 has a first input terminal, a second input terminal, and an output terminal. The first input terminal of the tenth operational amplifier 326 is connected to a first preset voltage; the second input terminal of the tenth operational amplifier 326 is coupled to the control terminal of the second power transistor 310 .

[0219] The sixth switch 327 has a first terminal, a second terminal and a control terminal. The control terminal of the sixth switch 327 is coupled to the first input terminal of the ninth operational amplifier 321; and the second terminal of the sixth switch 327 is grounded.

[0220] The second capacitor 328 has a first terminal and a second terminal. The first terminal of the second capacitor 328 is coupled to the control terminal of the sixth switch 327 ; the second terminal of the second capacitor 328 is coupled to the first terminal of the sixth switch 327 .

[0221] The seventh switch 329 has a second terminal and a control terminal. The second terminal of the seventh switch 329 is connected to the power supply voltage VDD; and the control terminal of the seventh switch 329 is coupled to the first terminal of the sixth switch 327.

[0222] The eleventh current source 3210 has an input terminal and an output terminal. The input terminal of the eleventh current source 3210 is connected to the supply voltage VDD; the output terminal of the eleventh current source 3210 is coupled to the first terminal of the sixth switch tube 327 .

[0223] The twelfth current source 3213 has an input terminal and an output terminal. The input terminal of the twelfth current source 3213 is coupled to the first terminal of the seventh switch tube 329 ; and the output terminal of the twelfth current source 3213 is grounded.

[0224] The eleventh operational amplifier 3211 has a first input terminal, a second input terminal and an output terminal. The first input terminal of the eleventh operational amplifier 3211 is coupled to the first terminal of the seventh switch 329 ; the second input terminal of the eleventh operational amplifier 3211 is connected to a fourth preset voltage.

[0225] The twelfth operational amplifier 3212 has a first input terminal, a second input terminal, and an output terminal. The first input terminal of the twelfth operational amplifier 3212 is coupled to the control terminal of the second power transistor 310 ; the second input terminal of the twelfth operational amplifier 3212 is coupled to the first input terminal of the ninth operational amplifier 321 .

[0226] Please refer to Figure 4 The driving device further includes a driving power supply 600 having an input terminal and an output terminal, wherein the input terminal is connected to the power supply voltage VDD, and the primary winding further has a center tap terminal coupled to the output terminal of the driving power supply 600.

[0227] Please refer to Figure 6, which shows a schematic structural diagram of a driving power supply provided by an exemplary embodiment of the present application. The driving power supply includes an adjustable current source 610, a first transistor 620, a second transistor 630 and an impedance element 640. Figure 6 In the embodiment, the impedance element 640 is described as a resistor.

[0228] The adjustable current source 610 has an input terminal and an output terminal. The output terminal of the adjustable current source 610 is grounded.

[0229] The first transistor 620 has a first terminal and a control terminal. The first terminal of the first transistor 620 is coupled to the input terminal of the adjustable current source 610, and the control terminal is coupled to the first terminal of the first transistor 620.

[0230] The second transistor 630 has a first terminal and a control terminal. The first terminal of the second transistor 630 is coupled to the center tap terminal.

[0231] The impedance element 640 has a first terminal and a second terminal. The first terminal of the impedance element 640 is coupled to the control terminal of the second transistor 630 ; the second terminal of the impedance element 640 is coupled to the control terminal of the first transistor 620 .

[0232] In an embodiment of the present application, the driving power supply 600 provides a bias current through the center tap of the winding. When an adjustable current source 610 is used, the excitation electromagnetic field of the primary winding can be dynamically adjusted by changing the magnitude of the driving current to optimize the circuit performance.

[0233] In one embodiment, please refer to Figure 6 The driving power supply also includes a third transistor 650 and a fourth transistor 660.

[0234] The third transistor 650 has a first terminal, a second terminal, and a control terminal. The second terminal of the third transistor 650 is connected to the power supply voltage VDD; the first terminal of the third transistor 650 is coupled to the second terminal of the first transistor 620; and the control terminal of the third transistor 650 is coupled to the first terminal thereof.

[0235] The fourth transistor 660 has a first terminal, a second terminal, and a control terminal. The first terminal of the fourth transistor 660 is coupled to the second terminal of the second transistor; the second terminal of the fourth transistor 660 is connected to the power supply voltage VDD; and the control terminal of the fourth transistor 660 is coupled to the control terminal of the third transistor 650.

[0236] In one embodiment, the impedance element 640 is a field effect transistor, and the impedance element 640 further has a control terminal, and the control terminal is connected to the power supply voltage VDD.

[0237] Please refer to Figure 7, which shows a schematic diagram of the structure of a driving power supply provided by another exemplary embodiment of the present application, including a first field-effect transistor 641. The first end of an impedance element 640 is the drain of the first field-effect transistor 641; the second end of the impedance element 640 is the source of the first field-effect transistor 641; and the control end of the impedance element 640 is the gate of the first field-effect transistor 641. The drain of the first field-effect transistor 641 is coupled to the control end of the second transistor 630; the source of the first field-effect transistor 641 is coupled to the control end of the first transistor 620; and the gate of the first field-effect transistor 641 is connected to the supply voltage VDD.

[0238] In the embodiment of the present application, a field effect transistor is used as the impedance element 640, which is beneficial to improving the input impedance, and the voltage at the control end of the field effect transistor is directly controlled, so the required control power consumption is relatively low.

[0239] It should be noted that in the above Figure 6 ,and Figure 7 In the description, the first transistor 620 , the second transistor 630 , the third transistor 650 and the fourth transistor 660 are all field effect transistors. In the application process, other types of transistors can be used, and this embodiment does not constitute a limitation to this.

[0240] Furthermore, an impedance element 640 is added to the common gate connection between the first transistor 620 and the second transistor 630. By increasing the equivalent impedance at the common gate connection, the driver power supply 600 exhibits more stable performance under high-frequency signals. When a high-frequency signal is input to the adjustable current source 610, the increased equivalent impedance in the driver power supply 600 reduces signal reflection and loss, thereby improving signal transmission efficiency and quality. In particular, in a driver device 10 using a center-tapped transformer 500 to drive an ultrasonic transducer 400, increasing the equivalent impedance of the driver power supply 600 can provide the circuit with better frequency selectivity and lower energy loss.

[0241] The present application provides an ultrasonic transducer 400, as described above. Figure 4 As shown, it includes a transducer element 410. The transducer element 410 is coupled to the secondary winding of the transformer 500 in the driving device 10 provided in any of the above embodiments.

[0242] In one embodiment, the ultrasonic transducer 400 further includes a filter capacitor 420 .

[0243] In one embodiment, the ultrasonic transducer 400 further includes a voltage divider impedance 430 .

[0244] In one embodiment, the ultrasonic transducer 400 further includes a filter capacitor 420 and a voltage divider impedance 430 .

[0245] It should be noted that the technical solutions provided by the embodiments of this application can also be applied to other fields requiring precise control of power switching devices, such as DC-DC (Direct Current to Direct Current) converters and motor drive circuits. By appropriately adjusting the control parameters and circuit structure, the core technical concepts of this invention can be extended to various power electronics systems to solve problems such as oscillation and misconduction.

[0246] It should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each implementation method can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0247] The specific embodiments described above are intended to illustrate the present invention by way of example only. These embodiments are not exhaustive and are not intended to limit the scope of the present invention. Variations and modifications to the disclosed embodiments are possible, and other feasible alternative embodiments and equivalent variations of the elements in the embodiments will be apparent to those skilled in the art. Other variations and modifications to the disclosed embodiments do not exceed the spirit of the present invention and the scope of protection defined by the claims.

[0248] The series of detailed descriptions listed above are only specific descriptions of feasible implementation methods of the present invention. They are not intended to limit the scope of protection of the present invention. Any equivalent implementation methods or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A transformer driving circuit, characterized in that: The transformer includes a primary port, and the driving circuit includes: A power tube having a first end, a second end, and a control end, wherein the first end is coupled to the primary port and the second end is grounded. The power tube is turned on and off to drive the transformer. The first operational amplifier has a first input terminal, a second input terminal and an output terminal, wherein the output terminal is coupled to the control terminal of the power tube, and the output terminal is coupled to the second input terminal. A first current source has an input terminal and an output terminal, wherein the input terminal is connected to the supply voltage, and the output terminal is coupled to the first input terminal of the first operational amplifier. A second current source has an input terminal and an output terminal, wherein the input terminal is coupled to the first input terminal of the first operational amplifier, and the output terminal is grounded. The first switch has a first end and a second end, wherein the first end is connected to the power supply voltage and the second end is coupled to the control end of the power tube. The third switch tube has a first end, a second end, and a control end. The first end is grounded, the second end is coupled to the control end of the power tube, and the control end is coupled to the first input end of the first operational amplifier. In a first state, the first current source outputs a first current, the first switch is turned on, and the power tube is turned on. In the second state, the second current source outputs a second current, and the third switch tube is turned on to turn off the power tube.

2. The driving circuit according to claim 1, wherein: When the driving circuit receives the first control signal, the driving circuit sequentially reaches the third state and the first state. In the third state, the first current source outputs a third current until the voltage at the control end of the power tube is greater than a first preset voltage, and the third current is less than the first current.

3. The driving circuit according to claim 2, wherein: The driving circuit includes: The second operational amplifier has a first input terminal, a second input terminal and an output terminal, wherein the first input terminal is connected to a first preset voltage, and the second input terminal is coupled to the control terminal of the power tube. When the voltage at the control terminal of the power tube is less than the first preset voltage, the second operational amplifier outputs a first electrical signal, the first current source outputs a third current, and the drive circuit is in a third state. When the voltage at the control end of the power tube is greater than the first preset voltage, the second operational amplifier outputs a second electrical signal, the first current source outputs a first current, and the drive circuit is in a first state.

4. The driving circuit according to claim 1, wherein: When the driving circuit receives the second control signal, the driving circuit sequentially reaches the second state and the fourth state. In a fourth state, the second current source outputs a fourth current, and the fourth current is smaller than the second current.

5. The driving circuit according to claim 4, wherein: The driving circuit includes: The first switch tube has a first terminal, a second terminal and a control terminal, wherein the control terminal is coupled to the first input terminal of the first operational amplifier and the second terminal is grounded. The second switch tube has a first terminal, a second terminal and a control terminal, wherein the second terminal is connected to the power supply voltage and the control terminal is coupled to the first terminal of the first switch tube. A third current source has an input terminal and an output terminal, wherein the input terminal is connected to the supply voltage, and the output terminal is coupled to the first terminal of the first switch tube. a fourth current source having an input end and an output end, wherein the input end is coupled to the first end of the second switch tube, and the output end is grounded; The third operational amplifier has a first input terminal, a second input terminal and an output terminal, wherein the first input terminal is coupled to the first terminal of the second switch tube, and the second input terminal is connected to a fourth preset voltage. When the voltage at the first end of the second switch tube is greater than the fourth preset voltage, the third operational amplifier outputs a third electrical signal, the second current source outputs a second current, and the driving circuit is in the second state. When the voltage at the first end of the second switch tube is less than the fourth preset voltage, the third operational amplifier outputs a fourth electrical signal, the second current source outputs a fourth current, and the drive circuit is in a fourth state.

6. The driving circuit according to claim 1 or 4, characterized in that: The driving circuit further includes: The first switch tube has a first terminal, a second terminal and a control terminal, wherein the control terminal is coupled to the first input terminal of the first operational amplifier and the second terminal is grounded. The capacitor element has a first end and a second end, wherein the first end is coupled to the control end of the first switch tube, and the second end is coupled to the first end of the first switch tube. In the second state, the second current source outputs a second current, and the voltage of the first input terminal of the first operational amplifier drops to a second preset voltage and then remains there until the difference between the voltage of the control terminal of the power tube and the voltage of the first input terminal of the first operational amplifier drops to a third preset voltage. The second preset voltage corresponds to the voltage of the control terminal of the first switching tube in the Miller plateau period.

7. The driving circuit according to claim 6, wherein: The driving circuit includes: The second switch tube has a first terminal, a second terminal and a control terminal, wherein the second terminal is connected to the power supply voltage and the control terminal is coupled to the first terminal of the first switch tube. A third current source has an input terminal and an output terminal, wherein the input terminal is connected to the supply voltage, and the output terminal is coupled to the first terminal of the first switch tube. a fourth current source having an input end and an output end, wherein the input end is coupled to the first end of the second switch tube, and the output end is grounded; The third operational amplifier has a first input terminal, a second input terminal and an output terminal, wherein the first input terminal is coupled to the first terminal of the second switch tube, and the second input terminal is connected to a fourth preset voltage. a fourth operational amplifier having a first input terminal, a second input terminal, and an output terminal, wherein the first input terminal is coupled to the control terminal of the power tube, and the second input terminal is coupled to the first input terminal of the first operational amplifier; When the voltage at the first end of the second switch tube is greater than the fourth preset voltage, the third operational amplifier outputs a third electrical signal, the second current source outputs a second current, and the drive circuit is in a second state. When the voltage at the first end of the second switching tube is less than the fourth preset voltage, the third operational amplifier outputs a fifth electrical signal, and the second current source stops outputting until the difference between the voltage at the control end of the power tube and the voltage at the first input end of the first operational amplifier is less than the third preset voltage, the fourth operational amplifier outputs a sixth electrical signal, controls the second current source to output a fourth current, and the drive circuit is in a fourth state.

8. The driving circuit according to claim 7, wherein: The fourth operational amplifier has a bias voltage equal to a third preset voltage.

9. A driving device for an ultrasonic transducer, characterized in that: The ultrasonic transducer includes a transducer element, and the driving device includes: The transformer has a primary winding and a secondary winding, wherein the secondary winding is used to couple the transducer element, and the primary winding has a first primary port and a second primary port. The first driving circuit, configured according to claim 1, comprises a first power tube, a first end of the first power tube is coupled to the first primary port, and a second end of the first power tube is grounded. The second driving circuit, configured according to claim 1, comprises a second power tube, a first end of the second power tube is coupled to the second primary port, and a second end of the second power tube is grounded. The first power tube and the second power tube are alternately turned on to drive the ultrasonic transducer.

10. The driving device according to claim 9, characterized in that The driving device comprises: The driving power supply has an input terminal and an output terminal, wherein the input terminal is connected to the power supply voltage. The primary winding further has a center tap end, and the center tap end is coupled to the output end of the driving power supply.

11. The driving device according to claim 10, characterized in that: The driving power supply comprises: An adjustable current source having an input terminal and an output terminal, wherein the output terminal is grounded. The first transistor has a first terminal and a control terminal, wherein the control terminal is coupled to the first terminal, and the first terminal is coupled to the input terminal of the adjustable current source. A second transistor has a first terminal and a control terminal, wherein the first terminal is coupled to the center tap terminal. The impedance element has a first end and a second end, wherein the first end is coupled to the control end of the second transistor, and the second end is coupled to the control end of the first transistor.

12. The driving device according to claim 11, characterized in that The impedance element is a resistor.

13. The driving device according to claim 11, characterized in that The impedance element is a field effect tube, The impedance element further has a control terminal, wherein the control terminal is connected to a supply voltage.

14. An ultrasonic transducer, characterized in that: include: Transducer element, The driving device according to any one of claims 9 to 13, wherein the secondary winding of the transformer in the driving device is coupled to the transducer element.

15. The ultrasonic transducer according to claim 14, characterized in that The ultrasonic transducer further comprises: Filter capacitors, and / or voltage divider impedances.

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