Motor driving circuit, stepping motor driver and wire welding machine

Abstract

The utility model belongs to the field of motor control, and relates to a motor driving circuit, a stepping motor driver and a wire bonder, the motor driving circuit comprises an upper computer, a programmable gate array, a first coil control module, a second coil control module, a first coil and a second coil; the programmable gate array is connected with the upper computer, the first coil control module and the second coil control module are connected with the programmable gate array, the first coil is connected with the first coil control module, and the second coil is connected with the second coil control module. The upper computer regularly outputs a first displacement signal to the programmable gate array, and the programmable gate array outputs a second displacement signal to the first coil control module and the second coil control module, so that the first coil control module and the second coil control module respectively control the first coil and the second coil to drive the motor. According to the invention, mechanical vibration and electromagnetic noise during operation of the motor can be effectively reduced, so that the operation smoothness of the motor and the welding detection accuracy are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of motor control, and more particularly, to a motor driving circuit, a stepper motor driver and a wire bonding machine. BACKGROUND

[0002] As a key equipment in the semiconductor packaging process, the performance of the wire bonding machine directly affects the quality and efficiency of the packaging. Among the many components of the wire bonding machine, the wire feeding mechanism and its motor play a crucial role. The wire feeding mechanism is usually equipped with a stepper motor, which is responsible for driving the spool to rotate to continuously and stably supply gold wire to the wire bonding assembly.

[0003] During the wire bonding process, the wire bonding assembly needs to accurately bond the gold wire on the die and the support, which requires the supply amount of gold wire to match the consumption amount of the wire bonding assembly. Precise control of the stepper motor is the key to achieving this goal. When the wire bonding assembly sends a wire feeding request, the stepper motor receives the signal and starts to drive the spool to rotate, thereby releasing an appropriate amount of gold wire.

[0004] However, the stepper motor and its driving circuit generate electromagnetic noise during operation, which poses a potential threat to the NSD signal. The NSD signal is used to detect whether the gold wire is successfully bonded and is extremely sensitive to electromagnetic noise. Traditional stepper motor drivers use a switching type driving circuit, which can effectively control the current of the stepper motor, but during the instant when the switching device is turned on or turned off, a large amount of electromagnetic noise is generated, which interferes with the NSD signal and reduces the accuracy of the bonding detection. CONTENT OF THE INVENTION

[0005] The technical problem to be solved by the embodiments of the present application is how to effectively reduce the mechanical vibration and the degree of electromagnetic noise during the operation of the motor to improve the smoothness of the motor operation and the accuracy of the bonding detection.

[0006] To solve the above technical problems, the embodiments of the present application provide a motor driving circuit, which adopts the following technical solutions:

[0007] A motor driving circuit, comprising: an upper computer, a programmable gate array, a first coil control module, a second coil control module, a first coil and a second coil.

[0008] The programmable gate array is connected with the upper computer, the first coil control module and the second coil control module are connected with the programmable gate array, the first coil is connected with the first coil control module, and the second coil is connected with the second coil control module.

[0009] The host computer outputs a first displacement signal to the programmable gate array, and the programmable gate array outputs a second displacement signal to the first coil control module and the second coil control module, so that the first coil control module and the second coil control module control the first coil and the second coil to drive the motor, respectively.

[0010] Further, the frequency of the second displacement signal is K times of the frequency of the first displacement signal, wherein the K is 256.

[0011] Further, the first coil control module comprises:

[0012] a first digital-to-analog converter, a first comparison control unit, a first power amplifier, a first feedback amplifier, and a first enable switch.

[0013] The first digital-to-analog converter is connected to the programmable gate array, the first comparison control unit is connected to the first digital-to-analog converter, the first power amplifier is connected to the first comparison control unit, the first enable switch is connected to the positive electrode of the first coil, one end of the first feedback amplifier is connected to the negative electrode of the first coil, and the other end of the first feedback amplifier is connected to the first comparison control unit.

[0014] Further, the first comparison control unit comprises:

[0015] a first comparator, a first controller resistor, a second controller resistor, and a first controller capacitor.

[0016] The non-inverting input terminal of the first comparator is connected to the first digital-to-analog converter, the first controller resistor and the first controller capacitor are connected in series and then connected in parallel between the inverting input terminal of the first comparator and the output terminal of the first comparator, one end of the second controller resistor is connected to the inverting input terminal of the first comparator, and the other end of the second controller resistor is connected to the first feedback amplifier.

[0017] Further, the negative electrode of the first coil is further connected to a first grounding resistor, and the first grounding resistor is connected to a first grounding terminal.

[0018] Further, the second coil control module comprises:

[0019] a second digital-to-analog converter, a second comparison control unit, a second power amplifier, a second feedback amplifier, and a second enable switch.

[0020] The second digital-to-analog converter is connected with the programmable gate array, the second comparison control unit is connected with the second digital-to-analog converter, the second power amplifier is connected with the second comparison control unit, the second enable switch is connected with the positive pole of the second coil, one end of the second feedback amplifier is connected with the negative pole of the second coil, and the other end of the second feedback amplifier is connected with the second comparison control unit.

[0021] Further, the second comparison control unit comprises:

[0022] a second comparator, a third controller resistor, a fourth controller resistor, and a second controller capacitor.

[0023] The non-inverting input end of the second comparator is connected with the second digital-to-analog converter, the third controller resistor and the second controller capacitor are connected in series and then connected in parallel between the inverting input end of the second comparator and the output end of the second comparator, one end of the fourth controller resistor is connected with the inverting input end of the second comparator, and the other end of the fourth controller resistor is connected with the second feedback amplifier.

[0024] Further, the negative pole of the second coil is further connected with a second grounding resistor, and the second grounding resistor is connected with a second grounding end.

[0025] In order to solve the above technical problems, the embodiment of the application further provides a stepping motor driver, which adopts the motor driving circuit as described above.

[0026] In order to solve the above technical problems, the embodiment of the application further provides a wire bonding machine, which adopts the stepping motor driver as described above.

[0027] Compared with the prior art, the embodiment of the application has the following beneficial effects:

[0028] The motor driving circuit comprising the upper computer, the programmable gate array, the first coil control module, the second coil control module, the first coil and the second coil is arranged, the first displacement signal and the second displacement signal output by the upper computer and the programmable gate array can effectively perform micro-step subdivision control on the first coil control module and the second coil control module, so that the first coil and the second coil can reach a higher equivalent subdivision coefficient when working, the mechanical vibration and the electromagnetic noise degree of the motor when running can be effectively reduced, and the smoothness of the motor operation and the accuracy of the welding detection can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the scheme in the application, the drawings required to be used in the following embodiment description will be briefly introduced, obviously, the drawings in the following description are some embodiments of the application, and other drawings can be obtained by those skilled in the art without paying creative labor on the basis of the drawings.

[0030] Figure 1 It is a structure schematic view of an optional embodiment of the motor drive circuit of the utility model.

[0031] Figure 2 It is a circuit structure schematic view of an optional embodiment of the motor drive circuit of the utility model.

[0032] The drawings are as follows: host computer 1, programmable gate array 2, first coil control module 3, second coil control module 4, first coil 5, second coil 6, host computer U0, programmable gate array U1, first digital-to-analog converter U2, first comparison control unit Group A, first comparator U3, first power amplifier U4, first feedback amplifier U5, first enable switch K1, first controller resistor R1, second controller resistor R2, first controller capacitor C1, second digital-to-analog converter U6, second comparison control unit Group B, second comparator U7, second power amplifier U8, second feedback amplifier U9, second enable switch K2, third controller resistor R3, fourth controller resistor R4, second controller capacitor C2, first grounding resistor R5, second grounding resistor R6, first grounding terminal GND1, second grounding terminal GND2. DETAILED DESCRIPTION

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the description herein is for describing particular embodiments only and is not intended to be limiting of the application; the description and the drawings are to be regarded as illustrative in nature and are not intended to be limiting of the application; the terminology used in the description and the claims of the application and the above description of the drawings includes the terms specifically mentioned above, as well as their derivatives.

[0034] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive of one another. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0035] In order to better understand the present application scheme for those skilled in the art, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings.

[0036] Reference Figure 1 The embodiment of the present application provides a motor driving circuit, comprising:

[0037] The host computer 1, the programmable gate array 2, the first coil control module 3, the second coil control module 4, the first coil 5, and the second coil 6 are connected.

[0038] The programmable gate array 2 is connected with the host computer 1, the first coil control module 3 and the second coil control module 4 are connected with the programmable gate array 2, the first coil 5 is connected with the first coil control module 3, and the second coil 6 is connected with the second coil control module 4.

[0039] The host computer 1 outputs the first displacement signal to the programmable gate array 2 in a timing manner, the programmable gate array 2 outputs the second displacement signal to the first coil control module 3 and the second coil control module 4, so that the first coil control module 3 and the second coil control module 4 control the first coil 5 and the second coil 6 to drive the motor respectively.

[0040] In this embodiment, the host computer 1 is responsible for generating and transmitting configuration information, enabling / disabling, displacement commands. Among them, the displacement command is sent to the field programmable gate array 2 (FPGA) at a fixed period. The field programmable gate array 2 (FPGA) is a highly flexible and programmable hardware platform, commonly used to implement complex control algorithms and high-speed data processing. The communication between the host computer 1 and the FPGA can be carried out through a high-speed interface (such as PCIe, AXI bus, etc.), to ensure real-time transmission and processing of data. The host computer 1 is responsible for generating the necessary configuration information, which is transmitted to the field programmable gate array 2 through a communication protocol (such as Ethernet, serial communication, USB, etc.). Enable (Enable) and disable (Disable) are key commands to control the safe start and stop of the device. After receiving the enable command from the host computer 1, the field programmable gate array 2 will generate a second displacement signal of corresponding frequency to make the first coil control module 3 and the second coil control module 4 enter the working state to execute the received other commands (such as displacement command). The disable command is used to safely stop the working state of the first coil control module 3 and the second coil control module 4, to avoid accidental actions. The first coil 5 and the second coil 6 are both set in the stepper motor, and the displacement command is generated by the host computer 1 (such as PLC, microcontroller, computer, etc.) and sent to the first coil control module 3 and the second coil control module 4 through the communication interface (such as serial port, CAN bus, Ethernet, etc.) through the field programmable gate array 2. After receiving the displacement command, the first coil control module 3 and the second coil control module 4 will control the power-on and power-off sequence of the first coil 5 and the second coil 6 (and other possible coils) according to the predetermined step angle and step number, to drive the stepper motor to reach the specified position.

[0041] A programmable gate array 2 (FPGA) is a kind of semiconductor integrated circuit, which is used for programming and configuration to realize specific logic functions. FPGA is mainly composed of the following key parts: programmable logic block (CLBS): programmable logic block is the basic building block of FPGA, which is used to realize various logic functions, each programmable logic block usually contains lookup table (LUTs), flip-flop (FFs) and other auxiliary circuits, LUTs are used to realize logic functions, and FFs are used to store state information. Programmable interconnection: programmable interconnection in FPGA is connected with each other through programmable interconnection to form a complex logic circuit, the interconnection network allows users to define the connection path between CLBs to realize the required logic function. Input / output block (IOBS): input / output block is responsible for the interface between FPGA and the outside world, which provides functions such as buffering, driving and level conversion for external signals. Configuration memory: the configuration memory of FPGA is used to store the user's logic design. After power-on or reset, FPGA will read the configuration information from the configuration memory and load it into CLBs, interconnections and IOBs. Clock management module (CMBs): clock management module is used to generate and manage the clock signal inside FPGA, which provides clock division, frequency multiplication, phase adjustment and other functions to meet the needs of different logic blocks for clock signals.

[0042] The motor driving circuit including the host computer 1, the programmable gate array 2, the first coil control module 3, the second coil control module 4, the first coil 5 and the second coil 6 can effectively microstep subdivide the first coil control module 3 and the second coil control module 4 through the first displacement signal and the second displacement signal output by the host computer 1 and the programmable gate array 2, so that the first coil 5 and the second coil 6 can reach a higher equivalent subdivision coefficient when working, effectively reduce the mechanical vibration and electromagnetic noise degree when the motor runs, and improve the smoothness of the motor operation and the accuracy of the welding detection.

[0043] The following is Figure 2The identification circuit elements in the figure are described as follows: U0 is a host computer, U1 is a programmable gate array, U2 is a first digital-to-analog converter, U3 is a first comparator, U4 is a first power amplifier, U5 is a first feedback amplifier, K1 is a first enable switch, R1 is a first controller resistor, R2 is a second controller resistor, C1 is a first controller capacitor, Group A is a first comparison control unit, U6 is a second digital-to-analog converter, U7 is a second comparator, U8 is a second power amplifier, U9 is a second feedback amplifier, K2 is a second enable switch, R3 is a third controller resistor, R4 is a fourth controller resistor, C2 is a first controller capacitor, Group B is a second comparison control unit, R5 is a first grounding resistor, R6 is a second grounding resistor, GND1 is a first ground terminal, and GND2 is a second ground terminal.

[0044] In an optional implementation of the embodiment, the frequency of the second displacement signal is K times the frequency of the first displacement signal, where K is 256.

[0045] In the embodiment, a timer is designed in the programmable gate array 2 (FPGA) to control the output frequency of the first digital-to-analog converter U2 and the second digital-to-analog converter U6, where the frequency of the timer is in a multiple relationship with the communication frequency of the host computer 1, the second displacement signal is generated by the timer, and the communication frequency of the host computer 1 is the frequency of the first displacement signal. Assuming that the communication period of the host computer 1 is T_comm and the output frequency of the DAC is f_DAC, the period T_timer of the timer should satisfy f_DAC=K / T_timer, where K is the multiple. Therefore, T_timer=T_comm*K / f_DAC_relative, where f_DAC_relative is the DAC frequency ratio relative to the communication frequency (i.e., f_DAC / (1 / T_comm)). For example, the period of the timer is 0.25 ms, the frequency of the first displacement signal is 4 KHz, the output frequency of the DAC is 1 MHz, and the value of K is 256. In the embodiment, the value of K can be set in the range of 64-1024, and can be adjusted correspondingly according to actual conditions.

[0046] The embodiment effectively controls the degree of micro-step subdivision again on the basis of micro-step subdivision, so as to achieve a higher equivalent subdivision coefficient and effectively reduce the vibration of the motor.

[0047] In an optional implementation of the embodiment, the first coil control module 3 includes:

[0048] The first digital-to-analog converter U2, the first comparison control unit GroupA, the first power amplifier U4, the first feedback amplifier U5, and the first enable switch K1.

[0049] The first digital-to-analog converter U2 is connected to the programmable gate array U1, the first comparison control unit GroupA is connected to the first digital-to-analog converter U2, the first power amplifier U4 is connected to the first comparison control unit GroupA, the first enable switch K1 is connected to the positive pole of the first coil 5, one end of the first feedback amplifier U5 is connected to the negative pole of the first coil 5, and the other end of the first feedback amplifier U5 is connected to the first comparison control unit GroupA.

[0050] In the embodiment, the first digital-to-analog converter U2 is used to convert digital signals into analog signals. By receiving digital control signals from the programmable gate array 2 (FPGA) and converting them into analog voltage signals, the current or voltage of the first coil 5 is controlled by the voltage signals. The first comparison control unit GroupA is a closed-loop control unit, which is used to compare the analog signals output by the first digital-to-analog converter U2 with the actual current or voltage of the first coil 5 (obtained through the first feedback amplifier U5), and then adjusts the output of the first power amplifier U4 according to the comparison result to maintain the stability of the coil current or voltage. The first power amplifier U4 is used to provide sufficient power to drive the first coil 5, by receiving control signals from the first comparison control unit GroupA and adjusting its output according to the signals to ensure that the first coil 5 receives the correct current or voltage. The first feedback amplifier U5 is used to monitor the current or voltage of the first coil 5 and convert it into a small signal, which is then sent back to the first comparison control unit GroupA, so that the first comparison control unit GroupA adjusts according to the actual state of the coil to achieve closed-loop control. The first enable switch K1 is used to control the switching state of the first coil 5. When the first enable switch K1 is open, current can flow through the first coil 5; when the first enable switch K1 is closed, the current is cut off. The first enable switch K1 is usually used to save energy when the coil does not need to work, or to cut off the current in an emergency.

[0051] The embodiment effectively realizes the control of the first coil 5 according to the received second displacement signal input by the programmable gate array 2, and effectively ensures the stability and correctness of the current and voltage of the first coil 5 in the control process, by setting the first coil control module 3 including the first digital-to-analog converter U2, the first comparison control unit GroupA, the first power amplifier U4, the first feedback amplifier U5, and the first enable switch K1.

[0052] In an optional implementation of the embodiment, the first comparison control unit Group A comprises:

[0053] a first comparator U3, a first controller resistor R1, a second controller resistor R2, and a first controller capacitor C1.

[0054] The non-inverting input terminal of the first comparator U3 is connected to the first digital-to-analog converter U2, the first controller resistor R1 and the first controller capacitor C1 are connected in series and then connected in parallel between the inverting input terminal of the first comparator U3 and the output terminal of the first comparator U3, one end of the second controller resistor R2 is connected to the inverting input terminal of the first comparator U3, and the other end of the second controller resistor R2 is connected to the first feedback amplifier U5.

[0055] In the embodiment, the first comparator U3 is used to compare the magnitudes of two input signals (one is an analog signal from the first digital-to-analog converter U2, and the other is a feedback signal from the first feedback amplifier U5). According to the comparison result, the first comparator U3 outputs a high-level or low-level signal, which is used to control the output of the first power amplifier U4 subsequently. The first controller resistor R1 and the first controller capacitor C1 form a simple RC circuit, which is used to provide phase compensation and stability. They can prevent the first comparator U3 from oscillating at high frequencies and ensure the stability of the system. The second controller resistor R2 is used to provide a reference voltage or current for the inverting input terminal of the first comparator U3. The value of the second controller resistor R2 affects the threshold of the first comparator U3, thereby determining when the first power amplifier U4 starts or stops outputting current.

[0056] The embodiment effectively realizes effective output adjustment control according to input signals and feedback signals by setting the first comparison control unit Group A comprising the first comparator U3, the first controller resistor R1, the second controller resistor R2, and the first controller capacitor C1, so that the current or voltage of the first coil 5 remains stable.

[0057] In an optional implementation of the embodiment, the negative pole of the first coil 5 is further connected to a first grounding resistor R5, and the first grounding resistor R5 is connected to a first grounding terminal GND1.

[0058] In the embodiment, the first grounding resistor R5 is used to safely discharge the induced electromotive force generated in the first coil 5 to the ground through the first grounding resistor R5 when the first coil 5 is powered off or the current suddenly decreases, so as to avoid generating an excessively high voltage or current impact and protect other elements in the circuit. The first grounding terminal GND1 is used to reduce electromagnetic interference, provide safety protection, and provide a stable potential for elements in the circuit.

[0059] The embodiment effectively protects the circuit elements from the influence of the first coil 5 on the normal work of the circuit when power is off or current suddenly decreases by connecting the first ground resistance R5 to the negative pole of the first coil 5 and connecting the first ground resistance R5 and the first ground terminal GND1.

[0060] In an optional implementation of the embodiment, the second coil control module 4 comprises:

[0061] a second digital-to-analog converter U6, a second comparison control unit GroupB, a second power amplifier U8, a second feedback amplifier U9, and a second enable switch K2;

[0062] The second digital-to-analog converter U6 is connected to the programmable gate array U1, the second comparison control unit GroupB is connected to the second digital-to-analog converter U6, the second power amplifier U8 is connected to the second comparison control unit GroupB, the second enable switch K2 is connected to the positive pole of the second coil 6, one end of the second feedback amplifier U9 is connected to the negative pole of the second coil 6, and the other end of the second feedback amplifier U9 is connected to the second comparison control unit GroupB.

[0063] In the embodiment, the functions of the second digital-to-analog converter U6, the second comparison control unit GroupB, the second power amplifier U8, the second feedback amplifier U9, and the second enable switch K2 in the circuit are the same as those of the first digital-to-analog converter U2, the first comparison control unit GroupA, the first power amplifier U4, the first feedback amplifier U5, and the first enable switch K1 in the circuit, and the functions are used for the second coil 6. Here, no further description is given.

[0064] The embodiment realizes the control of the second coil 6 according to the received second displacement signal input by the programmable gate array 2 by setting the second coil control module 4 comprising the second digital-to-analog converter U6, the second comparison control unit GroupB, the second power amplifier U8, the second feedback amplifier U9, and the second enable switch K2, and effectively ensures the stability and correctness of the current and voltage of the second coil 6 in the control process.

[0065] In an optional implementation of the embodiment, the second comparison control unit GroupB comprises:

[0066] a second comparator U7, a third controller resistance R3, a fourth controller resistance R4, and a second controller capacitor C2;

[0067] The in-phase input end of the second comparator U7 is connected with the second digital-analog converter U6, the third controller resistor R3 and the second controller capacitor C2 are connected in series and then connected in parallel between the reverse input end of the second comparator U7 and the output end of the second comparator U7, one end of the fourth controller resistor R4 is connected with the reverse input end of the second comparator U7, and the other end of the fourth controller resistor R4 is connected with the second feedback amplifier U9.

[0068] In the embodiment, the functions of the second comparator U7, the third controller resistor R3, the fourth controller resistor R4 and the second controller capacitor C2 are the same as the functions of the first comparator U3, the first controller resistor R1, the second controller resistor R2 and the first controller capacitor C1, and the functions are used for the second power amplifier U8, which will not be described here.

[0069] The second comparison control unit GroupB including the second comparator U7, the third controller resistor R3, the fourth controller resistor R4 and the second controller capacitor C2 is arranged in the embodiment, so that the output adjustment control according to the input signal and the feedback signal is effectively realized, and the current or voltage of the second coil 6 is kept stable.

[0070] In an optional implementation of the embodiment, the negative pole of the second coil 6 is further connected with a second grounding resistor R6, and the second grounding resistor R6 is connected with a second grounding end GND2.

[0071] In the embodiment, the second grounding resistor R6 is used to safely discharge the induced electromotive force generated in the second coil 6 to the ground through the second grounding resistor R6 when the second coil 6 is powered off or the current suddenly decreases, so as to avoid generating an excessively high voltage or current impact and protecting other elements in the circuit. The second grounding end GND2 is used to reduce electromagnetic interference, provide safety protection and provide a stable potential for elements in the circuit.

[0072] The second grounding resistor R6 is connected with the negative pole of the second coil 6, and the second grounding resistor R6 is connected with the second grounding end GND2 in the embodiment, so as to effectively protect the circuit elements and avoid affecting the normal work of the circuit when the second coil 6 is powered off or the current suddenly decreases.

[0073] The motor driving principle of the embodiment is as follows: when the FPGA is initialized, the initial phase ph a (0) of the A phase (the first coil) is set, which can be any angle. The initial angle of the B phase (the second coil) is ph b (0) = ph a (0) + 90°. The FPGA receives various configuration information of the upper computer 1, including the full-scale current I fs, micro-step subdivision coefficient n. When receiving the enable signal of the host computer 1, the first enable switch K1 is closed, the displacement instruction is received and rotated. The host computer 1 sends the displacement instruction to the FPGA every fixed time period (i.e. communication period T p ). There is another timer in the FPGA, which controls the output of the DAC (i.e. DAC output frequency f dac ), which is K times the communication frequency of the host computer 1. With respect to the rotation of the motor at a certain speed, the frequency of the sinusoidal current is fixed and is denoted as fdac. The phase of the sinusoidal wave increased in a communication period is:

[0074]

[0075] The phase of each micro-step is 90° / n. Then the number of micro-steps of the sinusoidal wave increased in a communication period Tp is

[0076] denoted as p(x);

[0077] The driver (the first coil control module 3 and the second coil control module 4) receives the mth displacement instruction p(m) at time t(m,0) = m*Tp. At this time, the received displacement instruction p(m) represents the number of micro-steps that need to be rotated in the next single communication period Tp. After receiving the displacement instruction p(m), the FPGA calculates the phase corresponding to the next DAC update time t(m,1) = (m+1 / K)*Tp and the DAC output. For example, the phase of phase A at time t(m,1) is:

[0078] ph a (m,1) = ph a (m,0) + p(m)*90° / n / k;

[0079] The phase at time t(m,2) is:

[0080] ph a (m,2) = ph a (m.1) + p(m)*90° / n / k;

[0081] The outputs of the A-phase DAC corresponding to times t(m,1) and t(m,2) are DAC a (m,1) = I fs *sin(ph a (m,1)) and DAC a (m,2) = I fs *sin(ph a (m,2)), respectively. It can be seen that the phase difference between the two output times in the present application is ph a (m,2) - ph a(m,1) = p(m) * 90° / n / k. Since the phase of each micro-step in the 1 / n micro-step subdivision is 90° / n, the actual effect is to perform a micro-step subdivision of p(m) / k again on the basis of the original 1 / n micro-step subdivision. Since the update frequency of the DAC is high (easily over 1MHz), the value of K (between 64-1024) can be large, so that p(m) / k << 1. Thus the equivalent micro-step subdivision coefficient is increased.

[0082] The embodiment of the present application further provides a step motor driver, comprising a power supply, a heat dissipation system, a motor driving circuit and a motor, wherein the power supply is connected with the motor driving circuit and the heat dissipation system, the motor driving circuit is connected with the motor for driving control, and the heat dissipation system is arranged close to the motor for heat dissipation of the motor, and the motor driving circuit adopts the motor driving circuit as described above.

[0083] The embodiment of the present application can effectively reduce the mechanical vibration and electromagnetic noise degree of the motor during operation, so as to improve the smoothness of the motor operation and the accuracy of the welding detection.

[0084] The embodiment of the present application further provides a wire welding machine, comprising a wire releasing mechanism, a welding mechanism and a step motor driver, wherein the step motor driver is connected with the wire releasing mechanism for controlling the wire releasing mechanism to release and take up the wire, and the welding mechanism is arranged close to the wire releasing mechanism for performing welding process on the wire released by the wire releasing mechanism.

[0085] The embodiment of the present application can effectively reduce the mechanical vibration and electromagnetic noise degree of the motor during operation, so as to improve the smoothness of the motor operation and the accuracy of the welding detection.

[0086] Obviously, the above-described embodiments are only some embodiments of the present application, but not all the embodiments of the present application, and the preferred embodiments of the present application are given in the drawings, but do not limit the patent scope of the present application. The present application can be realized in many different forms, and contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive. Although the present application is described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing specific embodiments, or equivalently replace some technical features. Any equivalent structure made by using the contents of the specification and drawings, directly or indirectly applied to other related technical fields, is also within the patent protection scope of the present application.

Claims

1. An electric motor drive circuit, characterized by, The motor driving circuit comprises: The host computer, the programmable gate array, the first coil control module, the second coil control module, the first coil and the second coil; The programmable gate array is connected with the host computer, the first coil control module and the second coil control module are connected with the programmable gate array, the first coil is connected with the first coil control module, and the second coil is connected with the second coil control module; The host computer outputs a first displacement signal to the programmable gate array, and the programmable gate array outputs a second displacement signal to the first coil control module and the second coil control module, so that the first coil control module and the second coil control module control the first coil and the second coil to drive the motor respectively.

2. The motor drive circuit of claim 1, wherein, The frequency of the second displacement signal is K times of the frequency of the first displacement signal, wherein K is 256.

3. The motor drive circuit of claim 1, wherein, The first coil control module comprises: The first digital-to-analog converter, the first comparison control unit, the first power amplifier, the first feedback amplifier and the first enable switch; The first digital-to-analog converter is connected with the programmable gate array, the first comparison control unit is connected with the first digital-to-analog converter, the first power amplifier is connected with the first comparison control unit, the first enable switch is connected with the positive electrode of the first coil, one end of the first feedback amplifier is connected with the negative electrode of the first coil, and the other end of the first feedback amplifier is connected with the first comparison control unit.

4. The motor drive circuit of claim 3, wherein, The first comparison control unit comprises: The first comparator, the first controller resistor, the second controller resistor and the first controller capacitor; The noninverting input terminal of the first comparator is connected with the first digital-to-analog converter, the first controller resistor and the first controller capacitor are connected in series and then connected in parallel between the inverting input terminal of the first comparator and the output terminal of the first comparator, one end of the second controller resistor is connected with the inverting input terminal of the first comparator, and the other end of the second controller resistor is connected with the first feedback amplifier.

5. The motor drive circuit of claim 3, wherein, The negative electrode of the first coil is also connected with a first grounding resistor, and the first grounding resistor is connected with a first grounding terminal.

6. The motor drive circuit of claim 1, wherein, The second coil control module comprises: The second digital-to-analog converter, the second comparison control unit, the second power amplifier, the second feedback amplifier and the second enable switch; The second digital-to-analog converter is connected with the programmable gate array, the second comparison control unit is connected with the second digital-to-analog converter, the second power amplifier is connected with the second comparison control unit, the second enable switch is connected with the positive electrode of the second coil, one end of the second feedback amplifier is connected with the negative electrode of the second coil, and the other end of the second feedback amplifier is connected with the second comparison control unit.

7. The motor drive circuit of claim 6, wherein, The second comparison control unit comprises: The second comparator, the third controller resistor, the fourth controller resistor and the second controller capacitor; The in-phase input end of the second comparator is connected with the second digital-analog converter, the third controller resistor and the second controller capacitor are connected in series and then connected in parallel between the reverse input end of the second comparator and the output end of the second comparator, one end of the fourth controller resistor is connected with the reverse input end of the second comparator, and the other end of the fourth controller resistor is connected with the second feedback amplifier.

8. The motor drive circuit of claim 6, wherein, The negative electrode of the second coil is further connected with a second grounding resistor, and the second grounding resistor is connected with the second grounding end.

9. A stepping motor driver characterized by comprising: The stepping motor driver adopts the motor driving circuit according to any one of claims 1 to 8.

10. A wire bonding machine characterized by comprising: The wire bonding machine adopts the stepping motor driver according to claim 9.

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