Constant-voltage and constant-current switching circuit and ultrasonic drive circuit

Abstract

The utility model discloses a constant-voltage and constant-current switching circuit and an ultrasonic drive circuit. The constant-voltage and constant-current switching circuit comprises an analog switch, an alternating current-to-direct current module and an integral operation circuit module, according to different use products of the analog switch, the analog switch, the AC-to-DC module and the integral operation circuit module have different connection relations, and the number of the AC-to-DC module and the number of the integral operation circuit module are also different. According to the constant-voltage and constant-current switching circuit and the ultrasonic driving circuit, the welding quality can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of ultrasonic welding of bonding machines, in particular to a constant voltage and constant current switching circuit and an ultrasonic driving circuit. Background Art

[0002] A bonder is a device used in semiconductor chip manufacturing. Its working principle is to weld metal wires, usually aluminum or gold, to metal pins on the surface of the chip. These metal wires are used to connect different parts on the chip to form circuits.

[0003] A piezoelectric ultrasonic transducer is an energy converter that uses piezoelectric ceramics to convert electrical energy into mechanical energy. It can convert alternating electrical signals into mechanical vibrations of a certain frequency and amplitude, which are then transmitted to the wedge welding head through a set of amplitude-changing rod devices that can change the amplitude. The welding head transfers the received vibration energy to the joint of the workpiece to be welded, realizing ultrasonic welding.

[0004] When the ultrasonic transducer is working, the impedance will change with the temperature. To ensure that each solder joint has good consistency, there are two main control methods: constant current and constant voltage.

[0005] Taking constant current as an example, the output current remains stable, the envelope is straight, and each welding point maintains the same output current, thus achieving good consistency. Figure 1 In some other scenarios, maintaining a stable voltage is more effective than maintaining a stable current. In this case, a constant voltage control mode is required. Figure 2 shown.

[0006] Existing technologies usually use software to perform adjustments by collecting the current voltage / current and comparing it with the set value. This adjustment method has several drawbacks:

[0007] 1. There is a certain delay in software control, and when the welding load changes drastically, it cannot be adjusted and stabilized in time;

[0008] 2. The hardware circuit only supports constant voltage or constant current. During the power-on self-test, only constant voltage or constant current can be used for frequency sweep, which cannot meet the needs of multiple scenarios. For example, when the load impedance is large, constant voltage frequency sweep will result in very low current, seriously affecting the frequency sweep accuracy.

[0009] 3. Unable to switch between constant current and constant voltage modes.

[0010] In the prior art, a utility model patent with patent publication number CN202026301U discloses a self-calibrating closed-loop AD conversion circuit. In operating mode, an input signal 1 is connected to an integrator 6 via an electronic switch 2. The output of integrator 6 is sampled and converted by an A / D converter 7. In calibration mode, the input of integrator 6 is grounded via an electronic switch 4, and the A / D converter 7 operates outside the specified voltage range to determine the channel error. The comparative document uses an electronic switch to control the integrator, solving the problem of finding a balance between accuracy and speed in a conventional charge-balanced V / F conversion circuit in a system. Utility Model Content

[0011] The technical problem to be solved by the utility model is to solve the problem of currently using software to adjust the constant current control or constant voltage control of the ultrasonic transducer.

[0012] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0013] A constant voltage and constant current switching circuit includes: an analog switch 310, an AC / DC converter module, and an integral operation circuit module. Depending on the product in which the analog switch 310 is used, the connection relationship between the analog switch 310, the AC / DC converter module, and the integral operation circuit module varies, as does the number of AC / DC converter modules and integral operation circuit modules.

[0014] In one embodiment of the present invention, when the analog switch 310 is an analog single-pole double-throw switch, and the analog single-pole double-throw switch is located at the end of the switching circuit:

[0015] The AC-DC module includes a first AC-DC module 321 and a second AC-DC module 322 having the same structure; the integral operation circuit module includes a first integral operation circuit module 331 and a second integral operation circuit module 332 having the same structure;

[0016] The current feedback output by the ultrasonic transducer is connected to the first AC-DC converter module 321 and the first integral operation circuit module 331 in sequence to form a constant current branch;

[0017] The voltage feedback output by the ultrasonic transducer is connected to the second AC-DC converter module 322 and the second integral operation circuit module 332 in sequence to form a constant voltage branch;

[0018] The outputs of the constant voltage branch and the constant current branch are connected to an analog single-pole double-throw switch.

[0019] In one embodiment of the present invention, when the simulated single-pole double-throw switch is located at the end of the switching circuit:

[0020] The A1 port of the simulated single-pole double-throw switch is connected to the output end of the constant current branch; the A2 port of the simulated single-pole double-throw switch is connected to the output end of the constant voltage branch;

[0021] The ENB port of the simulated single-pole double-throw switch is connected to the microcontroller MCU;

[0022] Simulate the B port output selection signal of a single-pole double-throw switch;

[0023] The single-chip microcomputer MCU sends a control signal to select the A1 port or the A2 port of the simulated single-pole double-throw switch to connect to the B port of the simulated single-pole double-throw switch.

[0024] In one embodiment of the present invention, when the analog switch 310 is an analog dual-channel single-pole double-throw switch:

[0025] The input end of the analog dual-channel single-pole double-throw switch is respectively connected to the current feedback and voltage feedback output by the ultrasonic transducer; the output end of the analog dual-channel single-pole double-throw switch is sequentially connected to the AC-DC module and the integral operation circuit module.

[0026] In one embodiment of the present invention, the output ends of the voltage feedback output by the ultrasonic transducer are respectively connected to the NO1 port and the CN2 port of the analog dual-way single-pole double-throw switch; the output ends of the current feedback output by the ultrasonic transducer are respectively connected to the NC1 port and the NO2 port of the analog dual-way single-pole double-throw switch; and the COM2 port of the analog dual-way single-pole double-throw is connected to the AC-to-DC module; the single-chip microcomputer MCU is connected to the IN1 port and the IN02 port of the analog dual-way single-pole double-throw switch; the COM2 port of the analog dual-way single-pole double-throw switch outputs a selection signal, and the single-chip microcomputer MCU controls the voltage feedback or current feedback to be connected to the COM2 port of the analog dual-way single-pole double-throw switch.

[0027] In one embodiment of the present invention, when the simulated single-pole double-throw switch is located at the head end of the switching circuit:

[0028] The AC-DC module includes a third AC-DC module 323 and a fourth AC-DC module 324 having the same structure;

[0029] The current feedback output by the ultrasonic transducer is connected to the third AC-DC module 323 and then connected to the input end of the analog single-pole double-throw switch;

[0030] The voltage feedback output by the ultrasonic transducer is connected to the fourth AC-DC module 324 and then to the input end of the analog single-pole double-throw switch;

[0031] The output end of the simulated single-pole double-throw switch is connected to the integral operation circuit module.

[0032] In one embodiment of the present utility model, the A1 port of the simulated single-pole double-throw switch is connected to the current feedback output by the ultrasonic transducer; the A2 port of the simulated single-pole double-throw switch is connected to the voltage feedback output by the ultrasonic transducer; the single-chip microcomputer MCU is connected to the ENB port of the simulated single-pole double-throw switch; the B port of the simulated single-pole double-throw switch outputs a selection signal; the single-chip microcomputer MCU sends a control signal to select the A1 port or the A2 port of the simulated single-pole double-throw switch to be connected to the B port of the simulated single-pole double-throw switch.

[0033] The present invention also provides an ultrasonic driving circuit, comprising the above-mentioned constant voltage and constant current switching circuit.

[0034] Compared with the prior art, the beneficial effects of the present invention are:

[0035] Constant voltage and constant current switching circuit:

[0036] It can switch between constant current and constant voltage welding output functions, and can realize constant current frequency sweep and constant voltage frequency sweep functions. The hardware does not require DIP switches, relays, or other devices; the corresponding function can be selected through software. Conventional software control: There is a delay. After waiting for feedback data to be collected, the software adjusts the parameters and then continues to collect feedback data, repeating the cycle. However, the software setting of this utility model: There is no delay. The constant current or constant voltage is set in advance, and the software does not need to calculate during operation. Low hardware complexity: Only a multiplexer and a few capacitors are required to realize the function, and it takes up little space and has little impact on other layouts of the ultrasonic drive circuit. Low cost: The additional cost of a single board is less than 1 yuan / PCS, which is suitable for mass production. The constant voltage or constant current function can be selected according to the type of welding material to obtain better ultrasonic welding results. Using analog switches instead of relays can avoid instantaneous signal jitter of the relay switch, and at the same time avoid the heat and unreliability hidden dangers of the relay remaining attracted for a long time, while significantly reducing the switching delay time.

[0037] Parameter calibration:

[0038] The current calibration is achieved, and the current output of each circuit board is consistent. In the constant current mode, the welding effect is stable and the solder joints are consistent. The voltage calibration is achieved, and the voltage output of each circuit board is consistent. In the constant voltage mode, the welding effect is stable and the solder joints are consistent. The impedance calibration is achieved to maintain the consistency of the transducer impedance measurement.

[0039] The hardware is simple and easy to use, requiring few peripherals. Current calibration only requires an oscilloscope, while voltage and impedance calibration can be completed with a 10-ohm standard resistor. Calibrated parameter values ​​are fixed and stored in a memory chip, requiring only one calibration for continued operation.

[0040] Current stabilization time control circuit:

[0041] The control of the current rise time is realized, and the current rise time can be controlled through the device settings. It can be controlled in multiple gears, and at least 8 gears can be set for control. The output effect corresponding to the gear is stable: the value of the same gear always remains stable, and will not change with use, affecting the consistency of the solder joints. Low hardware complexity: only one multiplexer and a few capacitors need to be added to realize the function, and it takes up little space and has little impact on other layouts of the ultrasonic drive circuit. Low cost: The additional cost of a single board is less than 1 yuan / PCS, which is suitable for mass production. Different gears can be selected according to the type of welding material to obtain better ultrasonic welding effects. Compared with switching devices such as relays, the multiplexer circuit used has the characteristics of multi-channel, easy control, low power consumption, and response block. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a schematic diagram of constant current output.

[0043] Figure 2 This is a schematic diagram of constant voltage output.

[0044] Figure 3 Schematic diagram of an AC to DC module according to an embodiment of the present invention.

[0045] Figure 4 Schematic diagram of an integral operation circuit module according to an embodiment of the present utility model.

[0046] Figure 5 The analog switch of the embodiment of the present utility model is a schematic diagram of an analog single-pole double-throw switch.

[0047] Figure 6 This is a schematic diagram of a simulated single-pole double-throw switch according to an embodiment of the present invention.

[0048] Figure 7 The analog switch of the embodiment of the present utility model is a schematic diagram of an analog dual-channel single-pole double-throw switch.

[0049] Figure 8 This is a schematic diagram of a simulated dual-channel single-pole double-throw switch according to an embodiment of the present invention.

[0050] Figure 9 The analog switch of another embodiment of the present invention is a schematic diagram of an analog single-pole double-throw switch.

[0051] Figure 10 This is a schematic diagram of the control connections of a simulated single-pole double-throw switch according to an embodiment of the present invention.

[0052] Figure 11 This is a schematic diagram of an ultrasonic driving circuit according to an embodiment of the present utility model.

[0053] Figure 12 Schematic diagram of a memory storage chip according to an embodiment of the present invention.

[0054] Figure 13 Schematic diagram of a parameter calibration device according to an embodiment of the present invention.

[0055] Figure 14 Schematic diagram of a sampling module according to an embodiment of the present invention.

[0056] Figure 15 Schematic diagram of the AC-DC amplifying module and filtering module according to an embodiment of the present utility model.

[0057] Figure 16 Schematic diagram of a bonding machine calibration system according to an embodiment of the present invention.

[0058] Figure 17 This is a schematic diagram of the output current measured before calibration of the ultrasonic transducer according to an embodiment of the present invention.

[0059] Figure 18 Schematic diagram of the output current measured after calibration of the ultrasonic transducer according to an embodiment of the present invention.

[0060] Figure 19 Schematic diagram of a current stabilization time adjustment module according to an embodiment of the present invention.

[0061] Figure 20 Schematic diagram of a specific circuit of the current stabilization time adjustment module according to an embodiment of the present invention.

[0062] Figure 21 This is a schematic diagram of the adjustment principle of the current stabilization time adjustment module according to an embodiment of the present utility model.

[0063] Figure 22 Schematic diagram of a multiplexer according to an embodiment of the present invention.

[0064] Figure 23 Schematic diagram of part of the control code of the multiplexer according to an embodiment of the present invention.

[0065] Figure 24 This is a schematic diagram of a radio frequency amplifier module according to an embodiment of the present invention. DETAILED DESCRIPTION

[0066] In order to facilitate those skilled in the art to understand the technical solution of the present invention, the technical solution of the present invention is further described in conjunction with the accompanying drawings.

[0067] The terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0068] Example 1

[0069] See also Figures 3 to 10 As shown, the present invention provides a constant voltage and constant current switching circuit suitable for use in a driving circuit of an ultrasonic transducer, comprising an analog switch 310, an AC / DC converter module, and an integral operation circuit module. Depending on the product in which the analog switch 310 is used, the connection relationship between the analog switch 310, the AC / DC converter module, and the integral operation circuit module may vary, as may the number of AC / DC converter modules and integral operation circuit modules.

[0070] In one embodiment of the present invention, the AC-DC module includes an operational amplifier U11B, resistors R21 , R22 , R23 , R24 , R25 , R28 , and diodes D5 and D6 .

[0071] One end of resistor R24 ​​is connected to the inverting input of operational amplifier U11B. Diodes D5 and D6 are connected in series and in parallel with resistor R22. The cathode of diode D5 is connected to the inverting input of operational amplifier U11B. Resistors R23 and R24 are connected in parallel. One end of the parallel connection of resistors R23 and R24 is connected to the anode of diode D6, and the other end is connected to resistors R21 and R24. Resistors R21 and R24 are also connected to the other ends of resistor R24. One end of resistor R28 is connected to the non-inverting input of operational amplifier U11B, and the other end is grounded.

[0072] In this embodiment, the integration operation circuit module includes an operational amplifier U6, resistors R17 and R18, and capacitors CS9, C15, and C14.

[0073] Resistor R17 is connected to the inverting input terminal of the operational amplifier U6, resistor R18 is connected to the non-inverting input terminal of the operational amplifier U6, both ends of capacitor CS9 are connected to the inverting input terminal and output terminal of the operational amplifier U6 respectively, one end of capacitor C15 is connected to the non-inverting input terminal of the operational amplifier U6, and the other end is grounded, and one end of capacitor C14 is connected to the positive power supply terminal of the operational amplifier U6, and the other end is grounded. Figure 4 As shown, in this embodiment, in the integral operation circuit, the actual value of the feedback can be understood as the output current signal value or voltage value of the ultrasonic transducer 10.

[0074] See also Figure 11As shown, the setting value output by the DAC can be understood as the setting value output by the DAC module 420. Furthermore, when the "current signal value or voltage value output by the electro-ultrasonic transducer 10" is not equal to the "setting value output by the DAC module 420," the integral operation circuit adjusts the output voltage / current, thereby causing the electro-ultrasonic transducer 10 to output a voltage / current until the "current signal value or voltage value output by the electro-ultrasonic transducer 10" is equal to the "setting value output by the DAC module 420," thereby achieving the effect of controlling the voltage / current value. In this embodiment, adjustment is performed by capacitor CS9, but without a gear adjustment. In another embodiment of the present invention, the control voltage / current value can also be adjusted, and the current stabilization time adjustment module 200 can be applied to achieve gear adjustment of the current stabilization time.

[0075] In one embodiment of the present invention, see Figure 5 As shown, when the analog switch 310 is an analog single-pole double-throw switch, and the analog single-pole double-throw switch is located at the end of the switching circuit:

[0076] The AC / DC module includes a first AC / DC module 321 and a second AC / DC module 322 of identical structure, which can be understood as two AC / DC modules. The first AC / DC module 321 and the second AC / DC module 322 are defined as such for ease of description. The integral operation circuit module includes a first integral operation circuit module 331 and a second integral operation circuit module 332 of identical structure. The first integral operation circuit module 331 and the second integral operation circuit module 332 are defined as such for ease of description.

[0077] The current feedback output by the ultrasonic transducer is connected to the first AC-DC converter module 321 and the first integral operation circuit module 331 in sequence to form a constant current branch.

[0078] The voltage feedback output by the ultrasonic transducer is connected to the second AC-DC converter module 322 and the second integral operation circuit module 332 in sequence to form a constant voltage branch.

[0079] The outputs of the constant voltage branch and the constant current branch are connected to an analog single-pole double-throw switch.

[0080] In one embodiment of the present invention, see Figure 6 As shown, the A1 port of the simulated single-pole double-throw switch is connected to the output end of the constant current branch, and the A2 port of the simulated single-pole double-throw switch is connected to the output end of the constant voltage branch.

[0081] The ENB port of the analog SPDT switch is connected to the MCU, specifically to the MCU's GPIO port, specifically port PA1. The B port of the analog SPDT switch outputs a selection signal. The MCU issues a control signal to connect either the A1 or A2 port of the analog SPDT switch to the B port of the analog SPDT switch. That is, when the MCU control signal "Choose" is a high-level logic 1, the current signal STATIC_I is connected to the B pin output, achieving constant current control. When the MCU control signal "Choose" is a low-level logic 0, the voltage signal STATIC_U is connected to the B pin output, achieving constant voltage control.

[0082] See Figure 7 As shown, in one embodiment of the present invention, when the analog switch 310 is an analog dual-channel single-pole double-throw switch:

[0083] The inputs of the analog dual-SPDT switch are connected to the current feedback and voltage feedback output by the ultrasonic transducer, respectively. The output of the analog dual-SPDT switch is connected in sequence to the AC-DC converter module and the integral operation circuit module. The output of the integral operation circuit module is connected to the input of the current stabilization time adjustment module 200.

[0084] See Figure 8 As shown, the output ends of the voltage feedback output by the ultrasonic transducer are respectively connected to the NO1 port and the CN2 port of the analog dual-channel single-pole double-throw switch, and the output ends of the current feedback output by the ultrasonic transducer are respectively connected to the NC1 port and the NO2 port of the analog dual-channel single-pole double-throw switch.

[0085] The COM2 port of the simulated dual-SPDT switch is connected to the AC-DC converter module, and the single-chip microcontroller (MCU) is connected to the IN1 and IN02 ports of the simulated dual-SPDT switch, specifically to the GPIO ports of the single-chip microcontroller, specifically ports PC1 and PC2. The COM2 port of the simulated dual-SPDT switch outputs a selection signal, and the MCU controls the connection of voltage feedback or current feedback to the COM2 port of the simulated dual-SPDT switch.

[0086] The IN1 and IN2 ports control an internal analog single-pole, double-throw switch, determining two states: connecting voltage feedback to the output for constant voltage. Connecting current feedback to the output for constant current. Furthermore, the ultrasonic transducer output voltage feedback is sensed by voltage transformer T3, while the ultrasonic transducer output current feedback is sensed by current transformer T4.

[0087] In one embodiment of the present invention, see Figure 9 and Figure 10As shown, when the analog switch 310 is an analog single-pole double-throw switch, and the analog single-pole double-throw switch is located at the head end of the constant-voltage constant-current switching module 300:

[0088] The AC-DC module includes a third AC-DC module 323 and a fourth AC-DC module 324 having the same structure.

[0089] The current feedback output by the ultrasonic transducer is connected to the third AC-DC module 323 and then connected to the input end of the analog single-pole double-throw switch.

[0090] The voltage feedback output by the ultrasonic transducer is connected to the fourth AC-DC module 324 and then to the input end of the analog single-pole double-throw switch.

[0091] The output end of the analog single-pole double-throw switch is connected to the integral operation circuit module, and the output end of the integral operation circuit module is connected to the input end of the current stabilization time adjustment module 200 .

[0092] In this embodiment, port A1 of the analog single-pole double-throw switch is connected to the current feedback output of the ultrasonic transducer; port A2 of the analog single-pole double-throw switch is connected to the voltage feedback output of the ultrasonic transducer. The microcontroller (MCU) is connected to port ENB of the analog single-pole double-throw switch, specifically to a GPIO port of the MCU, specifically port PA1. Port B of the analog single-pole double-throw switch outputs a selection signal. The MCU issues a control signal to select either port A1 or port A2 of the analog single-pole double-throw switch for connection to port B of the analog single-pole double-throw switch.

[0093] In this embodiment, the single chip microcomputer MCU selects the signal, selects the STATIC_I or STATIC_U signal, and connects it to the integral operation circuit module. Selecting "STATIC_I" realizes the constant current function, and selecting "STATIC_U" realizes the constant voltage function.

[0094] Example 2

[0095] There are errors in the consistency of electronic components themselves and the quality of welding. For example, there are certain deviations between the actual values ​​of resistors and capacitors and the standard values. These deviations will lead to inconsistent results such as voltage division and filtering. Since the signal has undergone multiple operational amplifications, the cumulative errors of the operational amplifiers at each level will lead to different final output results. Since there are certain differences in the hardware of the driving circuit of each ultrasonic transducer, the voltage, current, impedance and other parameters measured by each ultrasonic driver board are different. In the related art, there is no unified calibration of the parameters of the ultrasonic driver board. Failure to calibrate will mainly cause the following effects:

[0096] 1. Under the same parameters, the output current value of each circuit board is different, which affects the welding effect;

[0097] 2. The impedance measured on each circuit board has certain differences, which affects the evaluation of the transducer's temperature rise performance;

[0098] 3. If the voltage, current, and impedance of each circuit board are different, the actual output voltage and current will also be different in constant voltage, constant current, and other modes, affecting the welding firmness and solder joint type under the preset parameters.

[0099] Because ultrasonic transducers have equivalent capacitance and inductance, when ultrasonic waves are output, a period of stabilization is required for the current to rise from 0 mA to the set value. In the related art, there is no way to adjust the stabilization time of ultrasonic output.

[0100] The main impacts of not being able to adjust the stabilization time of ultrasonic output are:

[0101] 1. When the output stabilization time is short, the current rises rapidly, which can easily cause a huge overshoot, resulting in over-welding when the solder joint contacts, severe deformation, and poor final shape of the weld surface;

[0102] 2. When the stabilization time is long, the current rises slowly. For some scenarios with short single welding time, such as when the welding material is thick aluminum wire, the stabilization time takes up a considerable proportion of the total time, and the current during the stabilization time is much smaller than the stabilization current, resulting in insufficient total welding power and weak welds.

[0103] Furthermore, when welding wires of different materials, different current rise rates are often desired. For example, gold wire requires a longer stabilization time to smoothly reach the set value, while aluminum wire requires a faster current rise rate to quickly achieve higher power output. However, current ultrasonic technologies do not allow for adjustment of the current stabilization time.

[0104] See also Figure 11 As shown, to solve the above problems, the present invention also provides an ultrasonic driving circuit, including a single-chip microcomputer MCU, a DDS module 410, a DAC module 420, a current stabilization time adjustment module 200, a radio frequency amplifier module 430, a constant voltage and constant current switching module 300, and a memory storage chip U1. Among them, the constant voltage and constant current switching module 300 mainly comprises a constant voltage and constant current switching circuit.

[0105] See also Figures 12 to 18 As shown, in one embodiment of the present invention, a memory storage chip U1 is in communication with a single-chip microcomputer MCU. Parameter calibration data is written into the memory storage chip U1, and the parameter calibration data is used to calibrate the voltage, current and impedance of the ultrasonic drive circuit.

[0106] In this embodiment, a memory storage chip U1 with ferroelectric memory (FRAM) is used. This memory storage chip U1 (FRAM) maintains data even after a power outage. Calibrated data can be written to the memory storage chip U1 via I2C communication and read after each power-up. Therefore, calibration only needs to be performed once to obtain data, eliminating the need for subsequent recalibration.

[0107] Since the internal data of the memory chip is generally "0xFF" when it leaves the factory, a judgment will be made each time it is read to ensure that the read value is accurate and avoid misreading during the first use.

[0108] In the embodiment, memory storage chip U1 is provided with resistors R4, RS1, and capacitor C5. Resistor R4 is connected to the SDA port of memory storage chip U1, and resistor RS1 is connected to the SCL port of memory storage chip U1. The two ends of capacitor C5 are respectively connected to the VCC port and A0 port of memory storage chip U1. The communication port of the microcontroller MCU is respectively connected to the SDA port and SCL port of memory storage chip U1, and parameter calibration data is written to memory storage chip U1 via I2C communication.

[0109] The microcontroller (MCU) and memory chip U1 communicate via the I2C protocol. The MCU can perform operations such as writing, erasing, and reading data from memory chip U1. Resistors R4 and RS1 act as pull-up resistors, ensuring the I2C communication line remains pulled high when not transmitting data. Capacitor C5 acts as a filter capacitor, stabilizing the power input to memory chip U1 and reducing ripple interference.

[0110] In one embodiment of the present invention, parameter calibration data is obtained by a parameter calibration device. The parameter calibration device includes a sampling module 110, an AC-to-DC amplification module 120, a filtering module 130, an ADC chip 140, and a standard resistor, which are connected in sequence. Specifically, the ADC chip is a MAX1300.

[0111] In this embodiment, the sampling module 110 includes a voltage sampling capacitor C1 , a voltage dividing capacitor C4 , a voltage signal transformer T1 , a current signal transformer T2 , and a resistor R9 .

[0112] The voltage sampling capacitor C1 and the voltage divider capacitor C4 are connected in series, and terminals d1 and d2 are provided at both ends of the series branch of the voltage sampling capacitor C1 and the voltage divider capacitor C4. The voltage signal transformer T1 is connected in parallel with the voltage sampling capacitor C1, and the current signal transformer T2 and the resistor R9 are connected in parallel, and the resistor R9 is connected to the terminal d2.

[0113] The voltage signal transformer T1 senses and outputs the voltage across the voltage sampling capacitor C1, and the output signal is V_BACK. The current signal transformer T2 senses and outputs the voltage across the resistor R9, and the output signal is I_BACK. The transformer is essentially a small transformer, a voltage-type device, which can sense and output the voltage across the resistor R9 in a fixed ratio, such as 1:1. Here, the resistance value of resistor R9 is known. For example, if the resistor R9 is 1Ω, for example, if the induced voltage is 100mV, its current is 100mA. In this way, its voltage is obtained and the current is calculated. In addition, the output signal V_BACK and the output signal I_BACK are both AC signals.

[0114] Voltage sampling capacitor C1 and voltage divider capacitor C4 form a voltage divider circuit to prevent all voltage from being applied to voltage sampling capacitor C1. This ensures that voltage divider capacitor C4 has a certain equivalent capacitive reactance, preventing excessive current from flowing through voltage signal transformer T1. Resistor R9 is a sampling resistor with a relatively low resistance value, which does not affect normal operation.

[0115] In one embodiment of the present invention, the AC-DC amplifying module 120 includes an operational amplifier U2A, an operational amplifier U2B, resistors R1 , R2 , R3 , R5 , R6 , R7 , R10 , and R11 , capacitors C2 , C3 , and C6 , and diodes D1 and D2 .

[0116] The output port of the voltage signal transformer T1 or the output end of the current signal transformer T2 is connected in series with resistor R6 and then connected to the inverting input end of the operational amplifier U2B. Resistor R10 is connected to the non-inverting input end of the operational amplifier U2B and then grounded. The cathode of diode D1 is connected to the inverting input end of the operational amplifier U2B, and the anode is connected to the output end of the operational amplifier U2A.

[0117] Resistors R5 and R7 are connected in parallel, with one end connected to the anode of diode D2 and the other end connected to the inverting input of operational amplifier U2B. The cathode of diode D2 is connected to the anode of diode D1. Resistors R3 have one end connected to the inverting input of operational amplifier U2B and the other end connected to the anode of diode D2.

[0118] After the resistor R2 and the capacitor C2 are connected in parallel, the two ends are connected to the inverting input and output of the operational amplifier U2A respectively; and the non-inverting input of the operational amplifier U2A is connected to the resistor R11 and then grounded.

[0119] One end of the resistor R1 is connected to the output port of the voltage signal transformer T1 or the output end of the current signal transformer T2, and the other end is connected to the resistor R2.

[0120] The power supply terminal of the operational amplifier U2A is connected to the power supply, and the positive power supply terminal of the operational amplifier U2A is also connected to the capacitor C3 and then to the ground. In addition, the negative power supply terminal of the operational amplifier U2B is also connected to the capacitor C6 and then to the ground.

[0121] In one embodiment of the present invention, the filter module 130 includes a resistor R8 and a capacitor C7. One end of the resistor R8 is connected to the output end of the operational amplifier U2B, and the other end is connected to the capacitor C3 and the ADC chip 140. The capacitor C3 is also grounded.

[0122] In this embodiment, the data measured by the ADC chip 140 is sent to the single-chip microcomputer MCU, so that the single-chip microcomputer MCU knows the actual value of the current measurement data, specifically MAX1600.

[0123] In one embodiment of the present invention, the parameter calibration device can calibrate voltage, current, and impedance. The output signal of the transformer passes through an AC-to-DC converter composed of an operational amplifier, and then is filtered out of high-frequency interference by an RC filter. The output is a DC voltage OUT_AVERAGE. The ADC chip 140 collects the voltage, and the following relationship can be obtained:

[0124] Y=kx+b, where x is the effective value output by the voltage signal transformer T1 and the current signal transformer T2, Y is the effective value of OUT_AVERAGE, k is a fixed conversion coefficient, and b is a fixed bias value, which is a constant.

[0125] Specifically, calibrating the voltage includes:

[0126] Set the initial model for voltage calibration: Y1=k1x1+b1.

[0127] Connect the input and output ports of the ultrasonic transducer 10 to terminals d1 and d2, respectively, and to an AC power source. Ultrasonic transducer 10 is an external output device, providing the ultrasonic source for ultrasonic welding. It is driven by AC power. In this embodiment, ultrasonic transducer 10 undoubtedly includes a built-in driver circuit.

[0128] First, when there is no current flowing through the ultrasonic transducer 10, the output signal of the voltage signal transformer T1 is 0. The independent variable X1 in the voltage calibration initial model is 0. The value measured by the ADC chip 140 is the value of the constant b1 in the voltage calibration initial model.

[0129] Subsequently, the ultrasonic transducer 10 is removed, and the two ends of the standard resistor are connected to the terminal d1 and the terminal d2 respectively. According to the resistance value of the standard resistor and the set output current value of the ultrasonic transducer 10, the effective voltage value of the output end of the voltage signal transformer T1 is obtained. In this embodiment, for the convenience of calculation, the resistance value of the standard resistor is 1Ω, and the output current value of the ultrasonic transducer 10 is set to 100mA. Specifically, the output current value of the ultrasonic transducer 10 is set by the bonding machine. The ultrasonic transducer 10 is set in the bonding machine. The bonding machine relies on the vibration of the ultrasonic transducer 10 to perform ultrasonic bonding of the gold wire. Therefore, the output current of the bonding machine is actually the output current of the ultrasonic transducer 10 output current.

[0130] The output signal of the voltage signal transformer T1 is converted from AC to DC through the AC-DC amplifier module 120, amplified, and then filtered by the filter module 130. The ADC chip 140 is used as a sampling chip to measure the actual voltage value. The ratio of the actual voltage value to the effective voltage value measured by the ADC chip 140 is used as the fixed conversion coefficient K1 for the initial model of voltage calibration. In this embodiment, since the standard resistor has no equivalent capacitance and inductance, its voltage must be equal to 10Ω*100mA=1V, that is, the effective value of V_BACK. By measuring the value of OUT_AVERAGE at this time, the fixed conversion coefficient K1 can be calculated.

[0131] Finally, the obtained fixed conversion coefficient K1 and constant b1 are brought into the initial voltage calibration model to obtain the optimal voltage calibration model.

[0132] In one embodiment of the present invention, when calibrating the current:

[0133] Set the initial model for current calibration: Y2=k2x2+b2.

[0134] The input port and the output port of the ultrasonic transducer 10 are connected to the connection terminal d1 and the connection terminal d2 respectively, and are connected to an AC power supply.

[0135] First, when there is no current flowing through the ultrasonic transducer 10, the output signal of the current signal transformer T2 is 0. The independent variable X2 in the current calibration initial model is 0. The value measured by the ADC chip 140 is the value of the constant b2 in the current calibration initial model.

[0136] Then, the ultrasonic transducer 10 is removed, and the two ends of the standard resistor are connected to the terminal d1 and the terminal d2 respectively; according to the resistance value of the standard resistor and the set output current value of the ultrasonic transducer 10, the effective current value of the output end of the current signal transformer T2 is obtained.

[0137] The output signal of the current signal transformer T2 is converted into DC power by the AC-DC amplification module 120 and amplified. After that, it is filtered by the filtering module 130 and the actual current value is measured by the ADC chip 140.

[0138] The ratio of the actual current value and the effective current value measured by the ADC chip 140 is used as the fixed conversion coefficient K2 of the current calibration initial model.

[0139] Finally, the obtained fixed conversion coefficient K2 and constant b2 are brought into the initial current calibration model to obtain the optimal current calibration model.

[0140] In one embodiment of the present invention, after the voltage and current are calibrated, the ultrasonic transducer 10 is driven to output, and the collected voltage value is divided by the current value to obtain the impedance of the ultrasonic transducer 10. Specifically, when calibrating the impedance:

[0141] After obtaining the optimal voltage calibration model and the optimal current calibration model;

[0142] Connect the ultrasonic transducer 10 to terminals d1 and d2 to drive the ultrasonic transducer 10 output. Connect the AC-to-DC amplification module 120 to either the output port of the voltage transformer T1 or the output port of the current transformer T2. Substitute the voltage value measured by the ADC chip 140 into the optimal voltage calibration model to obtain the calibration voltage. Substitute the current value measured by the ADC chip 140 into the optimal current calibration model to obtain the calibration current.

[0143] The calibration impedance is obtained according to the calibration voltage and the calibration current.

[0144] The present invention also provides an embodiment. In the above embodiment, a set of sampling modules 110 is used to simultaneously collect voltage and current, and then an AC to DC amplifier module 120, a filter module 130, an ADC chip 140 and a standard resistor are used to calibrate the voltage, current and impedance. However, the method for calibrating the current is relatively inconvenient. The above embodiment has been described. It has been explained that the ultrasonic transducer 10 is mounted in the bonding machine, and a calibration system is set in the bonding machine system. See the attached Figure 16 Therefore, in combination with an oscilloscope, the actual current is measured through the oscilloscope to observe the actual value, and then manually input it into the calibration system for compensation. Specifically, when calibrating the current, it includes:

[0145] The ultrasonic transducer 10 is connected to an AC power source.

[0146] The oscilloscope's current probe is clamped onto the circuit of the ultrasonic transducer 10, and a calibration current value is set. This calibration current value is then output as the output current value of the ultrasonic transducer 10. The oscilloscope measures the current at this point as the actual current value. The calibration current value is set by the bonding machine, and specifically, the calibration current value is 60 mA, which is the calibration current value.

[0147] Using a bonding machine system equipped with the ultrasonic transducer 10 , the actual current value is input into a calibration system of the bonding machine system to perform current calibration.

[0148] The calibration system sends the actual current value to the driver circuit board of the ultrasonic transducer 10. Upon receiving the data, the driver circuit board of the ultrasonic transducer 10 performs a "subtract or supplement" operation to bring the current value to the same level as the calibration current value. In this embodiment, the "subtract or supplement" operation involves subtracting the current if the current is greater than 60 mA, and increasing the current if the current is less than 60 mA to bring the current value closer to 60 mA.

[0149] See also Figures 12 to 18 As shown, in one embodiment of the present invention, the parameter calibration device uses the transformer principle of the mutual inductor to sense the voltage and current when the ultrasonic transducer is working; the sensed signal is an AC signal, which needs to be converted into a DC signal through an operational amplifier circuit, and then filtered through an RC filter and input into the ADC acquisition chip.

[0150] The voltage / current value of the ultrasonic transducer is in a fixed ratio to the value output by the transformer. The ratio of the transformer output value to the DC signal is also fixed. Therefore, the actual voltage / current value of the transducer can be calculated based on the data received by the ADC chip 140.

[0151] During calibration, when the output is 0, the bias value of the initial model is measured; an external 10-ohm standard resistor is used instead of the transducer to allow the voltage and current to reach a fixed value, such as 1V, and the fixed conversion coefficients are calculated in turn.

[0152] The obtained calibration data is written into the memory storage chip U1 through the I2C protocol. The data will be read every time the power is turned on, and will not be lost, so there is no need to recalibrate.

[0153] See also Figure 17 and Figure 18 As shown in FIG. 1 , the output current of the ultrasonic transducer 10 is set to 60 mA. Figure 17 The actual current measured before calibration is 59.13mA. Figure 18 The actual current measured after calibration is 59.96mA.

[0154] The current value here is the effective value of the actual work done by the AC power (59.13mA, 59.96mA). The error between the actual current value and the set value is generally required to be within 0.5mA. In this way, when each circuit board is set to the same value, the actual output current is close and the consistency is good.

[0155] If not calibrated, the same setting may result in some boards having high output values ​​and others having low output values, resulting in different solder joint sizes between different machines. It is even possible that two machines may have the same settings, but one has too low an output value and the wires fall off, while the other has too high an output value and the wires are flattened.

[0156] See also Figure 11 、 Figures 19 to 23 As shown, in one embodiment of the present invention, the single-chip microcontroller MCU is connected to the DDS module 410 and the DAC module 420, and the output of the DAC module 420 and the output of the constant voltage and constant current switching module 300 are connected to the input of the current stabilization time adjustment module 200. The output of the DDS module 410 and the output of the current stabilization time adjustment module 200 are connected to the input of the RF amplifier module 430. Specifically, the DDS module 410 is an AD9833, and the DAC module 420 is an SGM5348.

[0157] In one embodiment of the present invention, the current stabilization time adjustment module 200 includes a multiplexing module 210 and an operational amplifier module 220. The multiplexing module 210 includes a multiplexer U3 and a plurality of capacitors, and the capacitance values ​​of the plurality of capacitors gradually increase.

[0158] In this embodiment, the plurality of capacitors include capacitors CS1, CS2, CS3, CS4, CS5, CS6, CS7, and capacitor CS8. One end of capacitor CS1 is connected to pin 5 of multiplexer U3, one end of capacitor CS2 is connected to pin 4 of multiplexer U3, one end of capacitor CS3 is connected to pin 2 of multiplexer U3, one end of capacitor CS4 is connected to pin 1 of multiplexer U3, one end of capacitor CS5 is connected to pin 15 of multiplexer U3, one end of capacitor CS6 is connected to pin 14 of multiplexer U3, one end of capacitor CS7 is connected to pin 13 of multiplexer U3, one end of capacitor CS8 is connected to pin 12 of multiplexer U3, and the other ends of capacitors CS1, CS2, CS3, CS4, CS5, CS6, CS7, and CS8 are connected.

[0159] In one embodiment of the present invention, the multiplexing module 210 further includes a resistor RX1, one end of which is connected to pin 16 of the multiplexer U3, and the other end is connected to a power supply. The resistor RX1 is used to limit the power input of the multiplexer U3.

[0160] In one embodiment of the present invention, the INH, VEE, and VSS ports of multiplexer U3 are grounded, and the A, B, and C ports of multiplexer U3 are connected to the microcontroller MCU, specifically, to the GPIO ports PD4, PD5, and PD6 of the microcontroller MCU. Specifically, the model of multiplexer U3 is CD4051BNM96.

[0161] In one embodiment of the present invention, the operational amplifier module 220 is used to form an integral operation circuit to implement integral compensation in feedback control. Specifically, the operational amplifier module 220 includes an operational amplifier U5, resistors R15 and R16, and capacitors C11 and C13.

[0162] In this embodiment, the inverting input terminal of the operational amplifier U5 is connected to the third pin of the multiplexer U3 , and the output terminal of the operational amplifier U5 is connected to the 12th pin of the multiplexer U3 .

[0163] One end of resistor R15 is connected to the inverting input of operational amplifier U5, and the other end is connected to the feedback port of the actual signal value output by ultrasonic transducer 10. In this embodiment, the output end of constant voltage and constant current switching module 200 is connected to the other end of resistor R15. The ultrasonic transducer 10 is switched to constant current output or constant voltage output. After switching, the actual signal value output by ultrasonic transducer 10, i.e., the actual signal value is a current signal or a voltage signal, is output to operational amplifier U5.

[0164] One end of the resistor R16 is connected to the non-inverting input terminal of the operational amplifier U5, and the other end is connected to the port for setting the set signal value output by the ultrasonic transducer. In an embodiment, the DAC module 420 sets the set signal value output by the ultrasonic transducer. Also, if the constant voltage and constant current switching module 200 switches the ultrasonic transducer 10 to a constant voltage output, the set signal value of the DAC module 420 is a voltage value. If the constant voltage and constant current switching module 200 switches the ultrasonic transducer 10 to a constant current output, the set signal value of the DAC module 420 is a current value. For example, the DAC module 420 can convert a digital signal into a voltage signal. For example, if a voltage of 200mV is desired, the single-chip microcomputer MCU sends a digital signal to the DAC module 420. The data contains 200mV of data. After receiving the data, the DAC chip will output 200mV.

[0165] The positive power supply terminal of the operational amplifier U5 is connected to the power supply and is also connected to the capacitor C11, which is also grounded. One end of the capacitor C13 is connected to the non-inverting input terminal of the operational amplifier U5, and the other end is grounded.

[0166] When the actual signal value output by the ultrasonic transducer is not equal to the set signal value output by the ultrasonic transducer, the integration circuit adjusts the output voltage or current, so that the ultrasonic transducer outputs current until the actual signal value output by the ultrasonic transducer is equal to the set signal value output by the ultrasonic transducer, thereby achieving the effect of controlling the current value.

[0167] In one embodiment of the present invention, the regulation principle is: the integral operation circuit mainly relies on the capacitor C to adjust the rate. Figure 21 As shown. Different circuits can be selected through the multiplexer U3, thereby selecting different capacitors to access the circuit. Figure 22 shown.

[0168] Multiplexer U3 is a digitally controlled analog switch with low ON impedance and very low OFF leakage current. It has three binary inputs, A, B, and C, and an INH control terminal. The three binary signals select one of the eight channels to be turned on and connect one of the eight inputs to the output. A partial program code example is shown below. Figure 23 shown.

[0169] Brief description of the code driving principle: The communication signal is sent by the host computer, such as the MCU, and is divided into three signals A, B, and C after analysis, and then output by three GPIOs.

[0170] See also Figure 1 、 Figures 19 to 23 As shown, when the current stabilization time adjustment module 200 is adjusted:

[0171] The single-chip microcomputer MCU controls the levels of the three ports A, B, and C of the multiplexer U3, which can open 8 different channels respectively to form a multi-channel analog switch.

[0172] The 8 paths are connected to capacitors of different sizes. You can connect the capacitor to the circuit by selecting the corresponding path.

[0173] After the capacitor is connected to the circuit, it forms an integral operation circuit with the operational amplifier module 220, performing integral compensation control in the current feedback. When the connected capacitors are of different sizes, the time required for integral compensation to equalize the actual signal value output by the ultrasonic transducer with the set signal value output by the ultrasonic transducer will also vary, resulting in different stabilization times for the circuit output.

[0174] See also Figure 24 As shown, in one embodiment of the present invention, the RF amplifier module 430 includes a RF amplifier U4, resistors R12, R13, R14, and capacitors C8, C9, C10, and C12.

[0175] The output end of the DDS module is connected to resistor R12, and resistor R12 is connected to pin 3 of the RF amplifier U4. The output end of the current stabilization time adjustment module 200 is connected to pin 1 of the RF amplifier U4. One end of resistor R13 is connected to the power supply, and the other end is connected to pin 2 of the RF amplifier U4. One end of resistor R14 is connected to pin 2 of the RF amplifier U4, and the other end is grounded. After capacitors C8 and C9 are connected in parallel, one end is connected to pin 8 of the RF amplifier U4, and the other end is grounded. After capacitors C10 and C12 are connected in parallel, one end is connected to pin 6 of the RF amplifier U4, and the other end is grounded. And, after pins 5 and 7 of the RF amplifier U4 are connected, the output is connected to the ultrasonic transducer 10. Among them. Between the RF amplifier module 430 and the ultrasonic transducer 10, for example, an operational amplifier and a power amplifier are arranged in sequence. The operational amplifier filters the output signal of the RF amplifier module 430, amplifies the current signal or voltage signal, and then inputs it to the power amplifier. The power amplifier does not change the voltage or current, nor does it change the frequency, but improves the driving capability and transmits it to the ultrasonic transducer 10 for output.

[0176] In one embodiment of the present invention, the DDS module 410 generates a fixed frequency signal and communicates with the microcontroller MCU via SPI.

[0177] See also Figures 3 to 24 As shown, in one embodiment of the present invention, when the ultrasonic driving circuit is driving:

[0178] The single-chip microcomputer MCU is powered on and runs, and reads the parameter calibration data written in the memory storage chip U1. The DDS module 410, the DAC module 420, the current stabilization time adjustment module 200, the RF amplifier module 430, and the constant voltage and constant current switching module 300 are calibrated through the parameter calibration data.

[0179] After the calibration is completed, the single chip microcomputer MCU sends instructions to the DDS module 410 and the DAC module 420 . After the DDS module 410 and the DAC module 420 receive the signals, the DDS module 410 outputs an AC frequency signal, and the DAC module 420 outputs a setting signal.

[0180] When the constant voltage constant current switching module 300 switches to output a voltage signal, the DAC module 420 outputs a setting signal as a DC voltage signal. When the constant voltage constant current switching module 300 switches to output a current signal, the DAC module 420 outputs a setting signal as a current signal.

[0181] The current stabilization time adjustment module 200 regulates the output signal of the constant voltage and constant current switching module 300 and the output setting signal of the DAC module 420 to make the output signal of the constant voltage and constant current switching module 300 equal to the output setting signal of the DAC module 420 and output a stable voltage or current signal.

[0182] The stable voltage or current signal and the AC frequency signal serve as inputs to the RF amplifier module 430 , which outputs an AC signal with both a controlled frequency and a controlled voltage or current to the ultrasonic transducer.

[0183] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the foregoing description. It is intended that all variations within the meaning and range of equivalents of the claims be encompassed within the present invention, and any reference numerals in the claims should not be construed as limiting the claims to which they relate.

[0184] The above-mentioned embodiments only represent the implementation methods of the utility model. The protection scope of the utility model is not limited to the above-mentioned embodiments. For those skilled in the art, several modifications and improvements can be made without departing from the concept of the utility model, which all fall within the protection scope of the utility model.

Claims

1. A constant voltage and constant current switching circuit, characterized in that: include: An analog switch (310), an AC-DC module, and an integral operation circuit module; when the analog switch (310) is an analog single-pole double-throw switch, and the analog single-pole double-throw switch is located at the end of the switching circuit: The AC-DC module comprises a first AC-DC module (321) and a second AC-DC module (322) having the same structure; the integral operation circuit module comprises a first integral operation circuit module (331) and a second integral operation circuit module (332) having the same structure; The current feedback output by the ultrasonic transducer is connected in sequence to the first AC-DC module (321) and the first integral operation circuit module (331) to form a constant current branch; The voltage feedback output by the ultrasonic transducer is connected in sequence to the second AC-DC module (322) and the second integral operation circuit module (332) to form a constant voltage branch; The outputs of the constant voltage branch and the constant current branch are connected to an analog single-pole double-throw switch.

2. The constant voltage and constant current switching circuit according to claim 1, characterized in that: The A1 port of the simulated single-pole double-throw switch is connected to the output end of the constant current branch; the A2 port of the simulated single-pole double-throw switch is connected to the output end of the constant voltage branch; The ENB port of the simulated single-pole double-throw switch is connected to the microcontroller MCU; Simulate the B port output selection signal of a single-pole double-throw switch; The single-chip microcomputer MCU sends a control signal to select the A1 port or the A2 port of the simulated single-pole double-throw switch to connect to the B port of the simulated single-pole double-throw switch.

3. A constant voltage and constant current switching circuit, characterized in that: include: An analog switch (310), an AC-DC module, and an integral operation circuit module; when the analog switch (310) is an analog dual-channel single-pole double-throw switch: The input end of the analog dual-channel single-pole double-throw switch is respectively connected to the current feedback and voltage feedback output by the ultrasonic transducer; the output end of the analog dual-channel single-pole double-throw switch is sequentially connected to the AC-DC module and the integral operation circuit module.

4. The constant voltage and constant current switching circuit according to claim 3, characterized in that: The output ends of the voltage feedback output by the ultrasonic transducer are respectively connected to the NO1 port and the CN2 port of the analog dual-channel single-pole double-throw switch; the output ends of the current feedback output by the ultrasonic transducer are respectively connected to the NC1 port and the NO2 port of the analog dual-channel single-pole double-throw switch; and the COM2 port of the analog dual-channel single-pole double-throw is connected to the AC-to-DC module; the single-chip microcomputer MCU is connected to the IN1 port and the IN02 port of the analog dual-channel single-pole double-throw switch; the COM2 port of the analog dual-channel single-pole double-throw switch outputs a selection signal, and the single-chip microcomputer MCU controls the voltage feedback or current feedback to be connected to the COM2 port of the analog dual-channel single-pole double-throw switch.

5. A constant voltage and constant current switching circuit, characterized in that: include: An analog switch (310), an AC-DC module, and an integral operation circuit module; when the analog switch (310) is an analog single-pole double-throw switch, and the analog single-pole double-throw switch is located at the head end of the switching circuit: The AC-DC module comprises a third AC-DC module (323) and a fourth AC-DC module (324) having the same structure; The current feedback output by the ultrasonic transducer is connected to the third AC-DC module (323) and then connected to the input end of the analog single-pole double-throw switch; The voltage feedback output by the ultrasonic transducer is connected to the fourth AC-DC module (324) and then connected to the input end of the analog single-pole double-throw switch; The output end of the simulated single-pole double-throw switch is connected to the integral operation circuit module.

6. The constant voltage and constant current switching circuit according to claim 5, characterized in that: The A1 port of the simulated single-pole double-throw switch is connected to the current feedback output by the ultrasonic transducer; the A2 port of the simulated single-pole double-throw switch is connected to the voltage feedback output by the ultrasonic transducer; the single-chip microcomputer MCU is connected to the ENB port of the simulated single-pole double-throw switch; the B port of the simulated single-pole double-throw switch outputs a selection signal; the single-chip microcomputer MCU sends a control signal to select the A1 port or the A2 port of the simulated single-pole double-throw switch to be connected to the B port of the simulated single-pole double-throw switch.

7. An ultrasonic driving circuit, characterized in that: The invention comprises the constant voltage and constant current switching circuit described in any one of claims 1 to 6.

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