Current driving circuit and driving chip

Abstract

The invention discloses a current driving circuit and a driving chip, the current driving circuit is applied to a to-be-driven motor with a low-pass characteristic, the current driving circuit comprises a chopping module, the chopping module is used for modulating a mismatch voltage signal into a high-frequency mismatch voltage signal, and the high-frequency mismatch voltage signal is filtered by the to-be-driven motor. Therefore, the influence of the mismatched voltage signal on the driving current signal of the to-be-driven motor is eliminated. The chopping module is combined with the to-be-driven motor with the low-pass characteristic, so that the influence of a mismatched voltage signal introduced by the front end of the operational amplifier of the driving loop on the driving current is avoided, and the current linearity is improved.

Description

Technical Field

[0001] The present application relates to the field of motor drive technology, and in particular to a current drive circuit and a drive chip. Background Art

[0002] Voice Coil Motor (VCM) is a type of motor that works on the principle of electric current moving under force in a magnetic field. It is widely used in various occasions that require precise control, such as mobile phone camera autofocus, hard disk read / write head positioning, etc. Its core features are high frequency response and high precision, which can respond quickly and achieve precise position control. In addition, VCM also has the advantages of simple structure and small size, which makes it perform well in many application scenarios.

[0003] Current VCMs are usually driven by linear current, with the output current controlled by an internal feedback loop. The H-bridge in the drive loop acts as a commutation switch to control the direction of the VCM.

[0004] However, in the related art, voltage mismatch often occurs at the input end of the operational amplifier of the driving loop, which affects the linearity of the output current and thus affects the operation of the VCM. Summary of the invention

[0005] In view of the above problems, the present application provides a current driving circuit and a driving chip to solve the above technical problems.

[0006] In a first aspect, the present application provides a current driving circuit, which is applied to a motor to be driven having a low-pass characteristic. The current driving circuit includes a chopping module, which is used to modulate a mismatch voltage signal into a high-frequency mismatch voltage signal, and the high-frequency mismatch voltage signal is filtered out by the motor to be driven to eliminate the influence of the mismatch voltage signal on the driving current signal of the motor to be driven.

[0007] In a possible implementation of the present application, the current driving circuit also includes a driving module, which is respectively connected to the chopping module and the motor to be driven; the chopping module is specifically used to frequency modulate the analog voltage signal connected and the mismatch voltage signal introduced by the driving module to obtain a control voltage signal output to the driving module, wherein the control voltage signal includes a low-frequency analog voltage signal and a high-frequency mismatch voltage signal, and the low-frequency analog voltage signal follows the analog voltage signal; the driving module is used to drive the motor to be driven to rotate based on the driving current signal according to the low-frequency analog voltage signal, wherein the driving current signal is obtained according to the analog voltage signal.

[0008] In a possible implementation of the present application, the chopping module includes a first chopping unit and a second chopping unit; the first chopping unit is used to frequency modulate the analog voltage signal according to a preset modulation signal to obtain a high-frequency analog voltage signal; the driving module is connected to the first chopping unit, and is used to perform voltage following on the high-frequency analog voltage signal and the mismatched voltage signal, and output them to the second chopping unit; the second chopping unit is connected to the driving module, and is used to frequency modulate the high-frequency analog voltage signal and the mismatched voltage signal according to the preset modulation signal to obtain a low-frequency analog voltage signal and a high-frequency mismatched voltage signal.

[0009] In a possible implementation of the present application, the driving module includes a voltage following unit and a driving unit; the voltage following unit is respectively connected to the first chopping unit and the second chopping unit, and is used to perform voltage following on the high-frequency analog voltage signal and the mismatch voltage signal, and output them to the second chopping unit; the driving unit is connected to the second chopping unit and the motor to be driven, and is used to drive the motor to be driven to rotate according to the low-frequency analog voltage signal.

[0010] In a possible implementation of the present application, the driving unit includes a first H-bridge, a driving transistor and a first driving resistor connected in series, the first H-bridge is connected to the power supply end, the first driving resistor is connected to the ground end, the motor to be driven is connected to the first H-bridge, the output end of the second chopping unit is connected to the control end of the driving transistor to output a low-frequency analog voltage signal and a high-frequency mismatch voltage signal, and the first connection node between the driving transistor and the first driving resistor is connected to an input end of the voltage follower unit through the first chopping unit.

[0011] In a possible implementation of the present application, the driving unit includes a second H-bridge and a second driving resistor connected in series, the second H-bridge is connected to the power supply end, the second driving resistor is connected to the ground end, the motor to be driven is connected to the second H-bridge, the output end of the second chopping unit is respectively connected to the control ends of the two NMOS tubes of the second H-bridge, and the second connection node of the second H-bridge and the second driving resistor is connected to an input end of the voltage follower unit through the first chopping unit.

[0012] In a possible implementation of the present application, the driving unit includes a third driving resistor and a third H-bridge connected in series, the third driving resistor is connected to the power supply end, the third H-bridge is connected to the ground end, the motor to be driven is connected to the third H-bridge, the output end of the second chopping unit is respectively connected to the control ends of the two PMOS tubes of the third H-bridge, and the third connection node of the third driving resistor and the third H-bridge is connected to an input end of the voltage follower unit through the first chopping unit.

[0013] In a possible implementation of the present application, the current driving circuit also includes a control module, which is connected to the chopping module and the driving module respectively; the control module is used to output an analog voltage signal to the chopping module, and output a digital commutation signal to the driving module to control the flow direction of the driving current signal.

[0014] In a possible implementation of the present application, the control module includes a main control unit and a digital-to-analog conversion unit; the main control unit is connected to the digital-to-analog conversion unit and the drive module, and is used to output a digital voltage signal to the digital-to-analog conversion unit, and output a digital commutation signal to the drive module; the digital-to-analog conversion unit is connected to the chopping module, and is used to convert the digital voltage signal into an analog voltage signal and output it to the chopping module.

[0015] In a second aspect, the present application also provides a driving chip, including a chip body and the above-mentioned current driving circuit arranged in the chip body.

[0016] From the above content, it can be concluded that the present application has the following beneficial effects:

[0017] The current driving circuit provided in the present application modulates the mismatched voltage signal into a high-frequency mismatched voltage signal through a chopping module. At the same time, combined with the low-pass characteristics of the motor to be driven, the high-frequency mismatched voltage signal can be filtered out, thereby avoiding the mismatched voltage signal from affecting the driving current signal of the motor to be driven, improving the current linearity, and further improving the reliability and performance of the motor to be driven, thereby ensuring the normal operation of the motor to be driven. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 It is a structural schematic diagram of a driving circuit in the related art;

[0020] Figure 2 yes Figure 1 A schematic diagram of current flow when the driving circuit shown in FIG. controls the voice coil motor to rotate forward;

[0021] Figure 3 yes Figure 1 A schematic diagram of current flow when the driving circuit shown in FIG. controls the reverse rotation of the voice coil motor;

[0022] Figure 4 yes Figure 1 A structural schematic diagram showing a voltage mismatch at the input terminal of an operational amplifier of a driving circuit shown in FIG.

[0023] Figure 5 It is a schematic diagram of a relationship curve between a driving current and a voltage control signal in the related art;

[0024] Figure 6 This is a schematic diagram of an application scenario of the current driving circuit provided in an embodiment of the present application;

[0025] Figure 7 is a structural schematic diagram of a current driving circuit provided in an embodiment of the present application;

[0026] Figure 8 is another structural schematic diagram of the current driving circuit provided in the embodiment of the present application;

[0027] Fig. 9 is a waveform diagram of a high-frequency mismatch voltage signal provided in an embodiment of the present application;

[0028] Fig.10 is a structural schematic diagram of a chopping module provided in an embodiment of the present application;

[0029] Fig.11 This is a signal frequency schematic diagram of the first chopping unit and the second chopping unit performing frequency modulation provided in the embodiment of the present application;

[0030] Fig.12 is a structural schematic diagram of a driving module provided in an embodiment of the present application;

[0031] Fig.13 is a schematic diagram of the structure of a driving unit provided in an embodiment of the present application;

[0032] Fig.14 yes Fig.13 An equivalent circuit diagram of a driving unit shown;

[0033] Fig.15 is another structural schematic diagram of a drive unit provided in an embodiment of the present application;

[0034] Fig.16 yes Fig.15 An equivalent circuit schematic diagram of a driving unit shown;

[0035] Fig.17 is another structural schematic diagram of a driving unit provided in an embodiment of the present application;

[0036] Fig.18 is another structural schematic diagram of the current driving circuit provided in the embodiment of the present application;

[0037] Fig.19It is a circuit principle schematic diagram of a current driving circuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0038] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0039] In order to enable those skilled in the art to better understand the solutions of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present application.

[0040] Before introducing the current driving circuit and driving chip of the present application, the relevant background information of the embodiments of the present application is first introduced.

[0041] like Figure 1 As shown, Figure 1 It is a structural diagram of a driving circuit in the related art, which includes a controller 101, a digital-to-analog converter 102, an operational amplifier A01, a driving tube N01, a tail resistor R01 and an H-bridge composed of four P tubes (P01-P04), a voice coil motor 103 connected between the four P tubes, and a position sensor 104 connected to the voice coil motor 103 to monitor the rotation position of the voice coil motor 103.

[0042] Specifically, the controller 101 controls the digital-to-analog converter 102 to output a voltage control signal V ctrl ' to the operational amplifier A01, and then output to the driver tube N01 through the voltage follower of the operational amplifier A01 to drive the driver tube N01 to be turned on; at the same time, the controller 101 outputs the digital signal (Bin0', Bin1') to control the conduction of a pair of P tubes on the diagonal line among the four P tubes of the H bridge to control the direction of the current flowing through the voice coil motor 103.

[0043] like Figure 2 As shown, when Bin0'=0 and Bin1'=1, the first P-tube P01 and the fourth P-tube P04 are turned on, and the current flows from the power supply VDD' through the first P-tube P01 from left to right through the voice coil motor 103, and then flows through the fourth P-tube P04 to the ground terminal GND. At this time, the current flowing through the voice coil motor 103 can drive the voice coil motor 103 to rotate clockwise, that is, the voice coil motor 103 rotates forward.

[0044] And as Figure 3 As shown, when Bin0'=1 and Bin1'=0, the second P-tube P02 and the third P-tube P03 are turned on, and the current flows from the power supply VDD' through the second P-tube P02 from right to left through the voice coil motor 103, and then flows through the third P-tube P03 to the ground terminal GND. At this time, the current flowing through the voice coil motor 103 can drive the voice coil motor 103 to rotate counterclockwise, that is, the voice coil motor 103 reverses.

[0045] According to the virtual short characteristics of the op amp, the voltage V loaded across the tail resistor R01 is V ctrl ', based on this, the driving current I can be calculated VCM '=V ctrl ' / R01, and then according to the calculation formula of Ampere force, the force F of the voice coil motor 103 can be calculated as F=BLI VCM '=BLV ctrl ' / R01.

[0046] but, Figure 1 In the driving circuit shown, a voltage mismatch may occur at the input end of the operational amplifier A01 , and the value of the mismatch voltage may be positive or negative. The introduced mismatch voltage may affect the driving current, thereby affecting the force of the voice coil motor 103 .

[0047] Combination Figure 4 and Figure 5 As shown, under ideal conditions, the voltage V p = Inverting input voltage V n , driving current I VCM ' and control voltage V ctrl The corresponding IV curve between Figure 5 As shown by the green line in . However, in the actual circuit, there is a voltage mismatch between the non-inverting input and the inverting input of op amp A01, that is, the non-inverting input voltage V p ≠Inverting input voltage V n , assuming the mismatch voltage is V os ', then V n =V p +V os '; If at this time V p = voltage control signal V ctrl ', then V n =V ctrl '+V os '.

[0048] If the mismatch voltage V os ' is greater than 0, when V p =V ctrl '=0,V n =V os ' will be greater than 0, making the drive current IVCM 'The starting point is greater than 0, such as Figure 5 The purple dashed line in the first quadrant is shown; when V n =V ctrl '+V os '=0,V p =V ctrl '=-V os ', that is, the control voltage V ctrl 'The starting point is less than 0, such as Figure 5 The red dotted line in the third quadrant is shown in Figure 2. Similarly, if the mismatch voltage V os ' is less than 0, the corresponding curve is Figure 5 The red dashed line in the first quadrant and the purple dashed line in the third quadrant.

[0049] That is, when the mismatch voltage V os ' is positive, it will cause the control voltage V ctrl ' is 0, the driving current I VCM ' is not 0; when the mismatch voltage V os ' is negative, it will cause the control voltage V ctrl 'Before reaching 0, the driving current I VCM ' is 0, that is, Figure 5 The circle surrounded by the yellow dotted line in the middle marks the dead zone that deviates from the ideal curve, which seriously affects the driving current I VCM ', thereby affecting the operation of the voice coil motor 103.

[0050] Based on this, the embodiments of the present application provide a current driving circuit and a driving chip, which are described in detail below.

[0051] See also Figure 6 , Figure 6 It is a schematic diagram of an application scenario of the current driving circuit provided in an embodiment of the present application. The current driving circuit 100 can be set on a terminal device 200 and connected to a motor 300 to be driven on the terminal device 200 to generate a driving signal output to the motor 300 to be driven, thereby driving the motor 300 to be driven to work.

[0052] The motor to be driven 300 may be a power device such as an existing motor or motor such as a VCM. The terminal device 200 may be an electronic device such as a mobile phone, a camera, a stereo, a notebook computer, a tablet computer, a desktop computer, etc.

[0053] It is understandable that in some other application scenarios, the current driving circuit 100 may also be independent of the terminal device 200, that is, the current driving circuit 100 is externally mounted on the terminal device 200 and connected to the motor 300 to be driven on the terminal device 200 to generate a driving signal output to the motor 300 to be driven, thereby driving the motor 300 to be driven to work.

[0054] Those skilled in the art will understand that Figure 6 The application environment shown in is only an application scenario adapted to the solution of the present application, and does not constitute a limitation on the application scenario of the solution of the present application. The current driving circuit 100 of the present application or the terminal device 200 integrating the current driving circuit 100 can be used in application scenarios such as imaging, audio amplifier, hard disk reading and writing, etc., which are not specifically limited here.

[0055] First, the present invention provides a current driving circuit. Figure 7 , Figure 7 It is a structural schematic diagram of a current driving circuit provided in an embodiment of the present application. The current driving circuit 100 can be applied to a motor 300 to be driven with a low-pass characteristic. The current driving circuit includes a chopping module 110. The chopping module 110 can be used to modulate the mismatch voltage signal into a high-frequency mismatch voltage signal, and the high-frequency voltage mismatch signal is filtered out by the motor 300 to be driven to eliminate the influence of the mismatch voltage signal on the driving current signal of the motor 300 to be driven.

[0056] In the embodiment of the present application, the motor 300 to be driven can be any existing motor or motor with low-pass characteristics, including but not limited to VCM, which can be determined according to the actual application scenario and is not limited here. The motor 300 to be driven has a low-pass characteristic, so it can allow low-frequency signals to pass through and block, i.e. filter, high-frequency signals.

[0057] It can be understood that the mismatch voltage signal is usually a DC signal, and the chopping module 110 modulates the mismatch voltage signal, which can be understood as frequency modulating the mismatch voltage signal to obtain a high-frequency mismatch voltage signal. The chopping module 110 can use any existing frequency modulator to modulate the mismatch voltage signal into a high-frequency mismatch voltage signal.

[0058] Since the motor 300 to be driven has a low-pass characteristic, the high-frequency mismatch voltage signal will be blocked by the motor 300 to be driven, and thus will not affect the driving current signal, and will not affect the operation of the motor 300 to be driven.

[0059] The current driving circuit 100 provided in the embodiment of the present application modulates the mismatched voltage signal into a high-frequency mismatched voltage signal through the chopping module 110. At the same time, combined with the low-pass characteristics of the motor 300 to be driven, the high-frequency mismatched voltage signal can be filtered out, thereby avoiding the mismatched voltage signal from affecting the driving current signal of the motor 300 to be driven, improving the current linearity, and further improving the reliability and performance of the motor 300 to be driven, ensuring the normal operation of the motor 300 to be driven.

[0060] Next, continue to Figure 7 The modules shown and the specific implementation methods that may be used in practical applications are described in detail.

[0061] like Figure 8 As shown, in some embodiments of the present application, the current driving circuit 100 may further include a driving module 120, which may be connected to the chopping module 110 and the motor to be driven 300, respectively. The chopping module 110 may be specifically used to frequency modulate the analog voltage signal connected and the mismatch voltage signal introduced by the driving module 120, and obtain a control voltage signal to output to the driving module 120, wherein the control voltage signal includes a low-frequency analog voltage signal and a high-frequency mismatch voltage signal, and the low-frequency analog voltage signal follows the analog voltage signal. The driving module 120 may be used to drive the motor to be driven 300 to rotate based on the driving current signal according to the low-frequency analog voltage signal, wherein the driving current signal is obtained according to the analog voltage signal.

[0062] It can be understood that the mismatch voltage introduced into the input terminal of the operational amplifier is a DC voltage signal. Therefore, in the embodiment of the present application, the mismatch voltage signal introduced into the driving module 120 is the mismatch voltage generated by the driving module 120 .

[0063] Specifically, the chopping module 110 receives the analog voltage signal, and the chopping module 110 is connected to the driving module 120, so that the mismatch voltage signal can also be received. In the embodiment of the present application, the chopping module 110 performs frequency modulation on the analog voltage signal and the mismatch voltage signal to obtain a control voltage signal, which includes a low-frequency analog voltage signal and a high-frequency mismatch voltage signal.

[0064] Among them, the low-frequency analog voltage signal follows the analog voltage signal, which can be understood as the frequency of the low-frequency analog voltage signal is the same as the frequency of the analog voltage signal, and the amplitude of the low-frequency analog voltage signal is the same as the amplitude of the analog voltage signal. In addition, if the possible delay in signal transmission is considered, the low-frequency analog voltage signal may also have a certain delay in phase relative to the analog voltage signal. Of course, in some scenarios, if the delay in signal transmission is not considered, the low-frequency analog voltage signal can also be considered to be synchronized with the analog voltage signal. The high-frequency mismatch voltage signal V OSHIt can be understood that the mismatch voltage signal V OS The corresponding signal, specifically, the high frequency mismatch voltage signal V OSH Can be the mismatch voltage signal V OS The signal is obtained after voltage following by the driving module 120 and frequency modulation by the chopping module 110.

[0065] As an example, the high frequency mismatch voltage signal V OSH It can be a square wave signal. It can be understood that a square wave is a periodic waveform signal whose voltage alternates between two different positive and negative levels, and the duty cycle of an ideal square wave is 50%. Therefore, Fig. 9 As shown in (a) and (b) in the present application, in the embodiment of the present application, the high frequency mismatch voltage signal V OSH It can be based on the mismatch voltage signal V OS The duty cycle is 50%, and the voltage is instantly switched between the first amplitude V1 and the second amplitude V2, where V1 = -V2, that is, the high-frequency mismatch voltage signal V OSH It is a signal whose amplitude continuously jumps between positive and negative.

[0066] Furthermore, since the motor 300 to be driven has a low-pass characteristic, it can allow the low-frequency analog voltage signal to pass through, while the high-frequency mismatch voltage signal V OSH It can be blocked to filter out the high-frequency mismatch voltage signal V OSH The impact on the driving current signal. Specifically, during low-pass filtering, when the signal frequency is higher than the cut-off frequency, the signal begins to attenuate, and the higher the frequency, the greater the attenuation. Fig. 9 As shown in (b) and (c) in .

[0067] Therefore, in the embodiment of the present application, the driving current signal flowing through the motor 300 to be driven can be obtained according to the low-frequency analog voltage signal, that is, the analog voltage signal, thereby avoiding the influence of the mismatched voltage signal on the motor 300 to be driven.

[0068] like Fig.10 As shown, in some embodiments of the present application, the chopping module 110 may include a first chopping unit 1101 and a second chopping unit 1102; the first chopping unit 1101 can be used to frequency modulate the analog voltage signal according to a preset modulation signal to obtain a high-frequency analog voltage signal; the driving module 120 is connected to the first chopping unit 1101, and can be used to perform voltage following on the high-frequency analog voltage signal and the mismatched voltage signal, and output them to the second chopping unit 1102; the second chopping unit 1102 is connected to the driving module 120, and can be used to frequency modulate the high-frequency analog voltage signal and the mismatched voltage signal according to a preset modulation signal to obtain a low-frequency analog voltage signal and a high-frequency mismatched voltage signal.

[0069] It can be known that chopping frequency shift technology is a technology that controls the output of the chopper circuit by changing the switching frequency of the switch tube. This technology adjusts the output voltage by adjusting the switching frequency, thereby achieving the purpose of control.

[0070] A chopper circuit is a circuit used to convert the constant DC output of a DC power supply into a pulse sequence with a variable voltage or variable pulse width. It controls the on and off of the power supply by quickly opening and closing the switch tube, thereby cutting the DC voltage output into a series of pulses. By changing the opening and closing time of the switch, the width or voltage of the pulse can be controlled. The current chopper circuit is usually composed of switching elements such as transistors, field effect tubes or thyristors, and the high-speed switching characteristics of these elements are used to achieve chopping.

[0071] In the embodiment of the present application, the first chopping unit 1101 and the second chopping unit 1102 may both adopt any existing chopping circuit, and the first chopping unit 1101 and the second chopping unit 1102 use the same modulation signal for frequency modulation.

[0072] In the embodiment of the present application, the first chopping unit 1101 can be set at the place where the driving module 120 has not introduced the mismatch voltage signal, so that only the received analog voltage signal can be frequency modulated, that is, frequency shifted. The analog voltage signal is usually a low-frequency signal. If the frequency of the analog voltage signal is f0, the analog voltage signal is frequency modulated by a high-frequency preset modulation signal (frequency is f), then a high-frequency analog voltage signal with a frequency of f0+f can be obtained. Fig.11 As shown in FIG. (a), the first chopping unit 1101 can convert the analog voltage signal V with a frequency of f0 into in Shift the frequency to the frequency point f0+f to obtain a high-frequency analog voltage signal V inh .

[0073] The high frequency analog voltage signal V inh After the driver module 120 is connected, the driver module 120 also introduces a DC mismatch voltage signal V OS Therefore, the driving module 120 can respectively inh and mismatch voltage signal V OS The voltage is followed and output to the second chopping unit 1102 .

[0074] like Fig.11 As shown in FIG. (b), in the embodiment of the present application, the second chopping unit 1102 can be connected to the high-frequency analog voltage signal V according to the preset modulation signal with a frequency of f. inh and mismatch voltage signal V OSFrequency modulation is also called frequency shifting. That is, the mismatch voltage signal V OS Shift the frequency to the frequency point f to obtain the high-frequency mismatch voltage signal V OSH , and the high-frequency analog voltage signal V with a frequency of f0+f inh The frequency is shifted to the frequency point f0, and a low-frequency analog voltage signal following the initial analog voltage signal is obtained; while the high-frequency mismatch voltage signal V OSH The frequency of the preset modulation signal is the same as f. In this way, the mismatch voltage signal V can be adjusted without affecting the analog voltage signal. OS The frequency shift is a high frequency mismatch voltage signal V OSH , thereby separating it from the frequency band of the low-frequency analog voltage signal, making it easier for the motor to be driven 300 with a low-pass characteristic to filter it out.

[0075] Since the motor 300 to be driven connected to the driving module 120 has a low-pass characteristic, after the low-frequency analog voltage signal and the high-frequency mismatched voltage signal are connected to the driving module 120, the motor 300 to be driven can filter the high-frequency mismatched voltage signal, so that the driving module 120 can drive the motor 300 to be driven to work according to the low-frequency analog voltage signal, eliminate the influence of the high-frequency mismatched voltage signal on the driving current signal, that is, eliminate the influence of the introduced mismatched voltage signal on the driving current signal, and improve the linearity of the driving current signal.

[0076] like Fig.12 As shown, in some embodiments of the present application, the driving module 120 may include a voltage following unit 1201 and a driving unit 1202; the voltage following unit 1201 is respectively connected to the first chopping unit 1101 and the second chopping unit 1102, and can be used to perform voltage following on the high-frequency analog voltage signal and the mismatch voltage signal, and output them to the second chopping unit 1102; the driving unit 1202 is connected to the second chopping unit 1102 and the motor 300 to be driven, and can be used to drive the motor 300 to be driven to rotate according to the low-frequency analog voltage signal.

[0077] It can be understood that the voltage follower unit 1201 performs voltage following on the high-frequency analog voltage signal and the mismatch voltage signal, that is, the output voltage directly follows the input voltage, that is, the output voltage of the voltage follower unit 1201 is also the high-frequency analog voltage signal and the mismatch voltage signal.

[0078] In the embodiment of the present application, the voltage follower unit 1201 can be implemented by any existing operational amplifier circuit with a voltage gain of 1, and the mismatch voltage signal introduced at the input end of the voltage follower unit 1201 is the mismatch voltage generated at the input end of the operational amplifier. The voltage follower unit 1201 can perform voltage following on the high-frequency analog voltage signal from the first chopping unit 1101 and the mismatch voltage signal introduced at its own input end, and then output the high-frequency analog voltage signal and the mismatch voltage signal to the second chopping unit 1102.

[0079] After the second chopping unit 1102 performs frequency modulation on the received high-frequency analog voltage signal and mismatch voltage signal, it can output a low-frequency analog voltage signal and a high-frequency mismatch voltage signal to the driving unit 1202. Since the motor 300 to be driven can filter the high-frequency mismatch voltage signal, the driving unit 1202 can drive the motor 300 to be driven to work according to the low-frequency analog voltage signal, thereby ensuring the reliability of the motor 300 to be driven.

[0080] like Fig.13 As shown, in some embodiments of the present application, the driving unit 1202 may include a first H-bridge, a driving transistor N1 and a first driving resistor R1 connected in series. The first H-bridge is connected to the power supply terminal VDD, the first driving resistor R1 is connected to the ground terminal GND, and the motor 300 to be driven is connected to the first H-bridge; the output end of the second chopping unit 1102 is connected to the control end of the driving transistor N1 to output a low-frequency analog voltage signal and a high-frequency mismatch voltage signal; the first connection node Z1 of the driving transistor N1 and the first driving resistor R1 is connected to an input end of the voltage follower unit 1201 through the first chopping unit 1101.

[0081] It can be understood that the first H-bridge includes four switching tubes, and the switching tubes can use any existing controllable transistors, including but not limited to triodes, for example, NPN BJT and PNP BJT in bipolar junction transistors (Bipolar Junction Transistor, BJT), N-type MOS tubes and P-type MOS tubes in metal-oxide semiconductor field-effect transistors (Metal-Oxide-SemiconductorField-Effect Transistor, MOSFET), etc. The specific selection can be based on the actual application scenario and is not limited here.

[0082] As an example, the voltage follower unit 1201 uses an operational amplifier A, and the first H-bridge includes a first PMOS tube P11, a second PMOS tube P12, a first NMOS tube N11, and a second NMOS tube N12. Among them, the first PMOS tube P11 and the second NMOS tube N12 are located on a diagonal line, the second PMOS tube P12 and the first NMOS tube N11 are located on another diagonal line, and the motor 300 to be driven is respectively connected to each switch tube of the first H-bridge. The control end of the driving transistor N1, that is, the gate, is connected to the second chopping unit 1102, the first end of the driving transistor N1 is respectively connected to the first NMOS tube N11 and the second NMOS tube N12, and the second end of the driving transistor N1 is connected to the grounded first driving resistor R1.

[0083] The second chopping unit 1102 outputs a low-frequency analog voltage signal and a high-frequency mismatch voltage signal to the control end of the driving transistor N1, and the driving transistor N1 is turned on. Since the motor 300 to be driven has a low-pass characteristic, the high-frequency mismatch voltage signal can be filtered by the motor 300 to be driven, and the motor 300 to be driven is driven to rotate based only on the low-frequency analog voltage signal. According to the virtual short characteristic of the operational amplifier A, the voltage at the first connection node Z1 is V in +V OS Since the motor 300 to be driven has a low-pass characteristic, the mismatch voltage signal V OS Impact on the driving current signal and improve current linearity.

[0084] Assuming that the motor 300 to be driven is a VCM, then Fig.14 Shown Fig.13 An equivalent circuit diagram of a driving unit is shown. In any conduction path, VCM, the first driving resistor R1, the driving transistor N1, the PMOS tube and the NMOS tube in the first H-bridge are a series circuit. The first driving resistor R1, the driving transistor N1, the PMOS tube and the NMOS tube in the first H-bridge will all divide the voltage of the power supply terminal VDD, that is, the first driving resistor R1, the driving transistor N1, the resistance of the PMOS tube and the NMOS tube in the first H-bridge will consume the voltage of the power supply terminal VDD, thereby reducing the voltage variation margin of VCM and reducing the maximum output drive current.

[0085] Based on this, Fig.15As shown, in some embodiments of the present application, the driving unit 1202 may include a second H-bridge and a second driving resistor R2 connected in series. The second H-bridge is connected to the power supply terminal VDD, the second driving resistor R2 is connected to the ground terminal GND, and the motor 300 to be driven is connected to the second H-bridge; the output end of the second chopping unit 1102 is respectively connected to the control ends of the two NMOS tubes of the second H-bridge, and the second connection node Z2 of the second H-bridge and the second driving resistor R2 is connected to an input end of the voltage follower unit 1201 through the first chopping unit 1101.

[0086] As an example, the voltage follower unit 1201 also uses an operational amplifier A, and the second H-bridge includes a third PMOS tube P21, a fourth PMOS tube P22, a third NMOS tube N21, and a fourth NMOS tube N22. Among them, the third PMOS tube P21 and the fourth NMOS tube N22 are located on a diagonal line, the fourth PMOS tube P22 and the third NMOS tube N21 are located on another diagonal line, and the motor 300 to be driven is connected to each switch tube of the second H-bridge respectively. The output end of the second chopping unit 1102 is connected to the control end of the third NMOS tube N21 through the first switch S1, and is connected to the control end of the fourth NMOS tube N22 through the second switch S2, and the second end of the third NMOS tube N21, the second end of the fourth NMOS tube N22, the first end of the second driving resistor R2, and the input end of the first chopping unit 1101 are connected to the second connection node Z2.

[0087] Compared to Fig.13 For the driving unit 1202, in this embodiment, the driving transistor N1 is reused with the NMOS transistor in the second H bridge, that is, the third NMOS transistor N21 and the fourth NMOS transistor N22 are both part of the H bridge and the driving transistor. Fig.16 It can be seen from the equivalent circuit shown that the driving unit 1202 in this embodiment can reduce the consumption of the voltage of the power supply terminal VDD by the transistor, increase the voltage variation margin of VCM, and thus increase the driving current margin.

[0088] like Fig.17 As shown, in some embodiments of the present application, the driving unit 1202 may include a third driving resistor R3 and a third H-bridge connected in series. The third driving resistor R3 is connected to the power supply terminal VDD, the third H-bridge is connected to the ground terminal GND, and the motor 300 to be driven is connected to the third H-bridge; the output end of the second chopping unit 1102 is respectively connected to the control ends of the two PMOS tubes of the third H-bridge, and the third connection node Z3 of the third driving resistor R3 and the third H-bridge is connected to an input end of the voltage follower unit 1201 through the first chopping unit 1101.

[0089] As an example, the voltage follower unit 1201 also uses an operational amplifier A, and the third H-bridge includes a fifth PMOS tube P31, a sixth PMOS tube P32, a fifth NMOS tube N31, and a sixth NMOS tube N32. Among them, the fifth PMOS tube P31 and the sixth NMOS tube N32 are located on a diagonal line, the sixth PMOS tube P32 and the fifth NMOS tube N31 are located on another diagonal line, and the motor 300 to be driven is respectively connected to each switch tube of the third H-bridge. The output end of the second chopping unit 1102 is connected to the control end of the fifth PMOS tube P31 through the third switch S3, and is connected to the control end of the sixth NMOS tube N32 through the fourth switch S4, and the first end of the fifth PMOS tube P31, the first end of the sixth PMOS tube P32, the second end of the third driving resistor R3, and the input end of the first chopping unit 1101 are connected to the third connection node Z3.

[0090] In this embodiment, the driving transistor N1 is reused with the PMOS transistor in the third H-bridge, that is, the fifth PMOS transistor P31 and the sixth PMOS transistor P32 are used as both a part of the H-bridge and as driving transistors, which can also reduce the transistor's consumption of the voltage of the power supply terminal VDD, increase the voltage variation margin of VCM, and thus increase the driving current margin.

[0091] like Fig.18 As shown, in some embodiments of the present application, the current driving circuit 100 may further include a control module 130, which may be connected to the chopping module 110 and the driving module 120 respectively; the control module 130 may be used to output an analog voltage signal to the chopping module 110, and output a digital commutation signal to the driving module 120 to control the flow direction of the driving current signal.

[0092] In an embodiment of the present application, the control module 130 can output analog voltage signals to the chopping module 110 to control the operation of the driving module 120, and output digital commutation signals to the driving module 120 to control the flow direction of the driving current signal, that is, to control the forward or reverse rotation of the motor 300 to be driven.

[0093] Specifically, the control module 130 may include a main control unit 1301 and a digital-to-analog conversion unit 1302; the main control unit 1301 is connected to the digital-to-analog conversion unit 1302 and the drive module 120, and can be used to output a digital voltage signal to the digital-to-analog conversion unit 1302, and output a digital commutation signal to the drive module 120; the digital-to-analog conversion unit 1302 is connected to the chopping module 110, and is used to convert the digital voltage signal into an analog voltage signal and output it to the chopping module 110.

[0094] In the embodiment of the present application, the main control unit 1301 can be any existing controller, including but not limited to a microcontroller unit (MCU), a system on chip (SOC), a central processing unit (CPU), etc. The specific controller can be determined according to the actual application scenario and is not limited here.

[0095] The main control unit 1301 can output a digital commutation signal such as Fig.13 , Fig.15 as well as Fig.17 Bin0 and Bin1 shown in the figure control the conduction of transistors on a diagonal line of the H bridge through the digital commutation signal, thereby controlling the direction of the driving current signal flowing through the motor 300 to be driven, that is, controlling the direction of the motor 300 to be driven.

[0096] The main control unit 1301 also outputs a digital voltage signal, such as “10011”, to the digital-to-analog conversion unit 1302 . The digital-to-analog conversion unit 1302 can convert the digital voltage signal into a corresponding analog voltage signal and output it to the chopping module 110 .

[0097] In this embodiment, the digital-to-analog conversion unit 1302 may adopt any existing digital-to-analog conversion circuit or digital-to-analog converter (DAC), which may be specifically determined according to the actual application scenario and is not limited here.

[0098] like Fig.19 As shown, as an example, if the main control unit 1301 generates a digital commutation signal (Bin0=0, Bin1=1), at this time, the third PMOS tube P21 is turned on, the second switch S2 is turned on, and the fourth NMOS tube N22 is turned on, and the driving current flows from the power supply terminal VDD through the third PMOS tube P21 from left to right through VCM, and then flows through the fourth NMOS tube N22 and the second driving resistor R2 to the ground terminal GND. At this time, the current flowing through VCM can drive VCM to rotate clockwise, that is, VCM rotates forward; at the same time, based on the frequency shift of the first chopping unit 1101 and the second chopping unit 1102, the mismatch voltage signal V introduced at the output end of the operational amplifier A is OS Converted into a high-frequency signal, combined with the low-pass characteristic of VCM, the V OS , avoid its influence on the driving current and improve the linearity of the driving current.

[0099] If the main control unit 1301 generates a digital commutation signal (Bin0=1, Bin1=0), at this time, the fourth PMOS tube P22 is turned on, the first switch S1 is turned on, and the third NMOS tube N21 is turned on, and the driving current flows from the power supply terminal VDD through the fourth PMOS tube P22 from right to left through VCM, and then flows through the third NMOS tube N21 and the second driving resistor R2 to the ground terminal GND. At this time, the current flowing through VCM can drive VCM to rotate counterclockwise, that is, VCM reverses; similarly, based on the frequency shift of the first chopping unit 1101 and the second chopping unit 1102, the mismatch voltage signal V introduced at the output end of the operational amplifier A is OS Converted into a high-frequency signal, combined with the low-pass characteristic of VCM, the V OS , avoid its influence on the driving current and improve the linearity of the driving current.

[0100] Based on the above embodiments, the present application also provides a driver chip, which may include a chip body and a Figures 6 to 19 Corresponding to the current driving circuit in any embodiment.

[0101] The driver chip may be an integrated circuit (IC), or microcircuit, microchip, or chip. The chip may be, but is not limited to, a system on chip (SOC) or a system in package (SIP) chip.

[0102] Since the driving chip is provided with the current driving circuit of the above embodiment, it has all the beneficial effects of the current driving circuit in any of the above embodiments, which will not be described in detail here.

[0103] In order to better implement the current driving circuit of the present application, the embodiment of the present application further provides a terminal device, which may include a motor to be driven and a current driving circuit or chip as described above connected to the motor to be driven. The terminal device may be, but is not limited to, an electronic device such as a camera, a mobile phone, a laptop computer, a tablet computer, and a stereo.

[0104] Since the terminal device is provided with the current driving circuit of the above embodiment, it has all the beneficial effects of the current driving circuit in any of the above embodiments, which will not be described in detail here.

[0105] The above are only preferred embodiments of the present application and are not intended to limit the present application in any form. Although the present application has been disclosed as a preferred embodiment as above, it is not intended to limit the present application. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present application. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application are still within the scope of the technical solution of the present application.

Claims

1. A current driving circuit, characterized in that: Applied to a motor to be driven with a low-pass characteristic, the current driving circuit includes a chopping module, which is used to modulate the mismatch voltage signal into a high-frequency mismatch voltage signal, and the high-frequency mismatch voltage signal is filtered out by the motor to be driven to eliminate the influence of the mismatch voltage signal on the driving current signal of the motor to be driven.

2. The current driving circuit according to claim 1, characterized in that: The current driving circuit further comprises a driving module, and the driving module is respectively connected to the chopping module and the motor to be driven; The chopping module is specifically used to perform frequency modulation on the analog voltage signal connected and the mismatch voltage signal introduced by the driving module to obtain a control voltage signal and output it to the driving module, wherein the control voltage signal includes a low-frequency analog voltage signal and the high-frequency mismatch voltage signal, and the low-frequency analog voltage signal follows the analog voltage signal; The driving module is used to drive the motor to be driven to rotate based on the driving current signal according to the low-frequency analog voltage signal, wherein the driving current signal is obtained according to the analog voltage signal.

3. The current driving circuit according to claim 2, characterized in that: The chopping module includes a first chopping unit and a second chopping unit; The first chopping unit is used to perform frequency modulation on the analog voltage signal according to a preset modulation signal to obtain a high-frequency analog voltage signal; The driving module is connected to the first chopping unit and is used to perform voltage following on the high-frequency analog voltage signal and the mismatch voltage signal, and output the signals to the second chopping unit; The second chopping unit is connected to the driving module, and is used to perform frequency modulation on the high-frequency analog voltage signal and the mismatch voltage signal according to the preset modulation signal to obtain the low-frequency analog voltage signal and the high-frequency mismatch voltage signal.

4. The current driving circuit according to claim 3, characterized in that: The driving module includes a voltage following unit and a driving unit; The voltage following unit is connected to the first chopping unit and the second chopping unit respectively, and is used to perform voltage following on the high-frequency analog voltage signal and the mismatch voltage signal, and output them to the second chopping unit; The driving unit is connected to the second chopping unit and the motor to be driven, and is used to drive the motor to be driven to rotate according to the low-frequency analog voltage signal.

5. The current driving circuit according to claim 4, characterized in that: The driving unit includes a first H-bridge, a driving transistor and a first driving resistor connected in series, the first H-bridge is connected to a power supply end, the first driving resistor is connected to a ground end, the motor to be driven is connected to the first H-bridge, the output end of the second chopping unit is connected to a control end of the driving transistor to output the low-frequency analog voltage signal and the high-frequency mismatch voltage signal, and a first connection node between the driving transistor and the first driving resistor is connected to an input end of the voltage follower unit through the first chopping unit.

6. The current driving circuit according to claim 4, characterized in that: The driving unit includes a second H-bridge and a second driving resistor connected in series, the second H-bridge is connected to a power supply end, the second driving resistor is connected to a ground end, the motor to be driven is connected to the second H-bridge, the output end of the second chopping unit is respectively connected to the control ends of two NMOS tubes of the second H-bridge, and the second connection node between the second H-bridge and the second driving resistor is connected to an input end of the voltage follower unit through the first chopping unit.

7. The current driving circuit according to claim 4, characterized in that: The driving unit includes a third driving resistor and a third H-bridge connected in series, the third driving resistor is connected to the power supply end, the third H-bridge is connected to the ground end, the motor to be driven is connected to the third H-bridge, the output end of the second chopping unit is respectively connected to the control ends of the two PMOS tubes of the third H-bridge, and the third connection node between the third driving resistor and the third H-bridge is connected to an input end of the voltage follower unit through the first chopping unit.

8. The current driving circuit according to any one of claims 2 to 7, characterized in that: The current driving circuit further comprises a control module, wherein the control module is connected to the chopping module and the driving module respectively; The control module is used to output the analog voltage signal to the chopping module, and output a digital commutation signal to the driving module to control the flow direction of the driving current signal.

9. The current driving circuit according to claim 8, characterized in that: The control module includes a main control unit and a digital-to-analog conversion unit; The main control unit is connected to the digital-to-analog conversion unit and the driving module, and is used to output a digital voltage signal to the digital-to-analog conversion unit, and output the digital commutation signal to the driving module; The digital-to-analog conversion unit is connected to the chopping module, and is used to convert the digital voltage signal into the analog voltage signal and output it to the chopping module.

10. A driver chip, characterized in that: The invention comprises a chip body and a current driving circuit as claimed in any one of claims 1 to 9 arranged on the chip body.

Images