Driving method, driving circuit of amplification module and electronic equipment

Abstract

The invention provides a driving method, a driving circuit of an amplification module and electronic equipment. The method comprises the following steps: when a power tube is conducted, outputting a first conduction current to a grid electrode of the power tube; after the gate-source voltage of the power tube rises to the threshold voltage, the first conduction current is reduced to the second conduction current, so that the reverse recovery current of the body diode corresponding to the power tube is reduced; after the gate-source voltage of the power tube is increased from the threshold voltage to the Miller voltage, the second conduction current is increased to third conduction current until the power tube is completely conducted; and when the power tube is turned off, the grid electrode of the power tube outputs a first turn-off current until the power tube is completely turned off. In the conduction process of the power tube, after the gate source voltage of the power tube rises to the threshold voltage, the first conduction current is reduced to the second conduction current, so that the reverse recovery current of a body diode corresponding to the power tube is reduced, overshoot of the power tube in the conduction process is avoided, and the conduction safety of the power tube is improved.

Description

Technical Field

[0001] The present invention relates to the field of amplifiers, and in particular to a driving method, a driving circuit of an amplifier module and electronic equipment. Background Art

[0002] After the input audio signal or the signal input through the DAC is modulated by the integrator, the classic closed-loop Class D amplifier will input the modulated signal and the triangular wave carrier into the comparator for comparison. According to the comparison result, the comparator outputs a square wave signal with different duty cycles to the drive circuit. After receiving the square wave signal, the drive circuit outputs the corresponding drive signal to control the conduction and cutoff of the output stage power tube to achieve the amplification of the square wave signal. Finally, the low-pass filter restores the amplified square wave signal to an audio sine signal, thereby achieving the amplification of the input audio signal.

[0003] Then, when the traditional driving circuit turns on the output stage power tube, there is a risk that the power tube will be broken down and burned due to overshoot, thereby reducing the safety of turning on the power tube.

[0004] Therefore, providing a driving method for improving power conduction safety has become a technical problem that needs to be solved urgently in the industry. Summary of the invention

[0005] The technical problem solved by the present invention is to provide a driving method, a driving circuit of an amplifying module and an electronic device, which solve the safety problem existing in the conduction process of the power tube.

[0006] In order to solve the above technical problems, a first aspect of the technical solution of the present invention provides a driving method for driving a power tube, comprising:

[0007] When the power tube is turned on:

[0008] Outputting a first conduction current to the gate of the power tube;

[0009] After the gate-source voltage of the power tube rises to a threshold voltage, reducing the first on-current to a second on-current to reduce a reverse recovery current of a body diode corresponding to the power tube;

[0010] After the gate-source voltage of the power tube rises from the threshold voltage to the Miller voltage, increasing the second conduction current to a third conduction current until the power tube is fully turned on;

[0011] When the power tube is turned off:

[0012] The gate of the power tube outputs a first turn-off current until the power tube is completely turned off.

[0013] Optionally, the first on-current is set to be greater than the third on-current.

[0014] Optionally, after increasing the second conduction current to a third conduction current, the method further includes:

[0015] After the drain-source voltage of the power tube drops to zero, the third conduction current is increased to a fourth conduction current.

[0016] Optionally, also include:

[0017] causing the gate of the power tube to output a second turn-off current;

[0018] After the gate-source voltage of the power tube drops to the Miller voltage, reducing the second off current to a third off current;

[0019] After the gate-source voltage of the power tube drops to the threshold voltage, the third turn-off current is increased to a fourth turn-off current until the power tube is completely turned off.

[0020] Accordingly, a second aspect of the technical solution of the present invention provides another driving method for driving an amplifying module, wherein the amplifying module includes a first power tube and a second power tube, wherein the drain of the first power tube is connected to a power supply voltage, the source of the first power tube is connected to the drain of the second power tube and serves as an output end of the amplifying module, and the source of the second power tube is connected to a ground end; the method includes:

[0021] When the second power tube is turned off, detecting a second gate-source voltage of the second power tube;

[0022] When the second gate-source voltage of the second power tube is less than or equal to the threshold voltage, turning on the first power tube;

[0023] When the first power tube is turned off, detecting a first gate-source voltage of the first power tube;

[0024] When the first gate-source voltage of the first power tube is less than or equal to the threshold voltage, turning on the second power tube;

[0025] Wherein, turning on the first power tube and turning on the second power tube both include:

[0026] Outputting a first conduction current to the gate of the power tube to be driven;

[0027] After the gate-source voltage of the power tube to be driven rises to the threshold voltage, the first conduction current is reduced to a second conduction current, so as to reduce the reverse recovery current of the body diode corresponding to the power tube to be driven;

[0028] After the gate-source voltage of the power tube to be driven rises from the threshold voltage to the Miller voltage, the second conduction current is increased to a third conduction current until the power tube to be driven is fully turned on.

[0029] Optionally, the first on-current is set to be greater than the third on-current.

[0030] Optionally, after increasing the second conduction current to a third conduction current, the method further includes:

[0031] After the drain-source voltage of the power tube drops to zero, the third conduction current is increased to a fourth conduction current.

[0032] Optionally, the first power tube and the second power tube both include: NMOS tubes.

[0033] Accordingly, a third aspect of the technical solution of the present invention provides a driving circuit of an amplifying module, wherein the amplifying module includes a first power tube and a second power tube, wherein the drain of the first power tube is connected to a power supply voltage, the source of the first power tube is connected to the drain of the second power tube and serves as an output end of the amplifying module, and the source of the second power tube is connected to a ground end, and the driving circuit includes:

[0034] A first driving module, the first driving module is used to turn on or off the first power tube according to the first control signal and the driving method provided by the first aspect of the technical solution of the present invention;

[0035] A second driving module, the second driving module is used to turn on or off the second power tube according to the driving method provided by the first aspect of the technical solution of the present invention according to the second control signal;

[0036] A bootstrap module, the bootstrap module is used to boost the output voltage of the amplifying module and use the boosted output voltage as the power supply voltage of the first driving module;

[0037] A logic control module and a level shift module, wherein the logic control module is used to receive a control square wave input from the outside, and output a first control signal to the level shift module according to the control square wave, the level shift module is used to perform level conversion on the first control signal and output a second control signal to the first driving module, and the logic control module is also used to output a third control signal to the second driving module according to the control square wave;

[0038] A threshold detection module, the threshold detection module is used to detect a first gate-source voltage of the first power tube and output it to the logic control module, the threshold detection module is also used to detect a second gate-source voltage of the second power tube and output it to the logic control module;

[0039] The logic control module is also used to output a second control signal when the first power tube is turned off, based on the first gate-source voltage being less than a threshold voltage, so that the second driving module controls the second power tube to be turned on; the logic control module is also used to output a first control signal when the second power tube is turned off, based on the second gate-source voltage being less than a threshold voltage, so that the first driving module controls the first power tube to be turned on.

[0040] Correspondingly, the fourth aspect of the technical solution of the present invention provides an electronic device, characterized in that it includes a driving circuit of the amplification module provided by the third aspect of the technical solution of the present invention.

[0041] Compared with the prior art, the technical solution of the embodiment of the present invention has the following beneficial effects:

[0042] In the driving method provided by the first aspect of the technical solution of the present invention, after the gate-source voltage of the power tube rises to the threshold voltage, the first on-current is reduced to the second on-current to reduce the reverse recovery current of the body diode corresponding to the power tube, thereby avoiding overshoot of the power tube during the conduction process, thereby improving the conduction safety of the power tube.

[0043] Furthermore, by setting the first on-current to be greater than the third on-current, and by setting the third on-current to be increased to the fourth on-current after the drain-source voltage of the power tube drops to zero, the rate of the power tube at different stages in the on-process is accelerated, thereby improving the on-efficiency of the power tube while ensuring the on-safety of the power tube. At the same time, in the Miller platform stage of the power tube on-state, the on-current is reduced to avoid excessive peak voltage.

[0044] Furthermore, the gate of the power tube is set to output the second shutdown current so that the gate-source voltage of the power tube drops to the Miller voltage; and after the gate-source voltage of the power tube drops to the threshold voltage, the gate of the power tube is set to output the fourth shutdown current until the power tube is completely shut down. Since the second shutdown current and the fourth shutdown current are both greater than the third shutdown current, the rate of the power tube at different stages of the shutdown process is accelerated, thereby improving the shutdown efficiency of the power tube. At the same time, in the Miller platform stage and the Miller platform to the threshold voltage stage when the power tube is shut down, the shutdown current is reduced to avoid excessive peak voltage and peak current.

[0045] In the driving method provided by the second aspect of the technical solution of the present invention, while the first power tube is turned off, the first gate-source voltage of the first power tube is detected. When the first gate-source voltage is less than or equal to the threshold voltage, the second power tube is turned on. While the second power tube is turned off, the second gate-source voltage of the second power tube is detected. When the second gate-source voltage is less than or equal to the threshold voltage, the first power tube is turned on. Through the above technical means, adaptive control of the dead time of the alternating conduction of the first power tube and the second power tube is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a waveform diagram of different parameters of the power tube in a conduction embodiment;

[0047] Figure 2 The process of the driving method provided by the technical solution of the present invention is Figure 1 ;

[0048] Figure 3 It is a waveform diagram of various parameters of a power tube turned on by the driving method provided by the technical solution of the present invention;

[0049] Figure 4 Schematic diagram of the circuit structure of the driving circuit provided by the embodiment of the present invention Figure 1 ;

[0050] Figure 5 is a conduction waveform diagram of a driving circuit provided by an embodiment of the present invention;

[0051] Figure 6 The process of the driving method provided by the technical solution of the present invention is Figure 2 ;

[0052] Figure 7 This is a waveform diagram of various parameters of a power tube turned off by the driving method provided by the technical solution of the present invention;

[0053] Figure 8 Schematic diagram of the circuit structure of the driving circuit provided by the embodiment of the present invention Figure 2 ;

[0054] Fig. 9 is a shutdown waveform diagram of a driving circuit provided by an embodiment of the present invention;

[0055] Fig.10 It is a circuit structure schematic diagram of a driving circuit of an amplifying module provided by the technical solution of the present invention. DETAILED DESCRIPTION

[0056] As described in the background art, in the prior art, when a power tube is turned on, there is a risk that the power tube is broken down and burned due to overshoot, thereby reducing the safety of turning on the power tube.

[0057] The following is an explanation of the problems existing in the prior art when turning on the power tube:

[0058] Before describing the problems existing in the prior art when turning on the power tube, the different stages that the power tube goes through during the turning-on process are described first:

[0059] in, Figure 1 It is a waveform diagram of different parameters of the power tube in a conduction embodiment.

[0060] Please refer to Figure 1 , the first stage: when the drive circuit outputs the conduction current acting on the gate of the power tube, the gate-source voltage of the power tube will rise from zero volts to the threshold voltage. Among them, the threshold voltage is specifically the conduction threshold voltage of the power tube, and the specific size is related to the size and type of the power tube, which is not limited here. In this stage, the drain-source voltage and drain current of the power tube are both zero.

[0061] The second stage: The gate-source voltage of the power tube will rise from the threshold voltage to the Miller voltage. Since the power tube can start to carry current after the gate-source voltage of the power tube rises to the threshold voltage, the drain current of the power tube in this stage rises from zero to the maximum current. The drain-source voltage of the power tube is still zero.

[0062] The third stage: The gate-source voltage of the power tube will always be maintained at the Miller voltage, so this stage is also called the Miller platform stage. In this stage, the power tube is gradually turned on, and the drain-source voltage of the power tube gradually drops to zero.

[0063] Stage 4: The gate-source voltage of the power tube rises from the Miller voltage to the maximum driving voltage, and the power tube is fully turned on.

[0064] Since there is a parasitic structure, namely the body diode, between the source and drain of the power tube, when the power tube is turned on, the body diode corresponding to the power tube will be turned off, thereby generating a reverse recovery current flowing from the negative electrode to the positive electrode, and then gradually recovering to zero. However, in the second stage of conduction, the conduction current of the power tube will flow from the drain of the power tube to the negative electrode of the body diode, thereby increasing the reverse recovery current of the body diode. In addition, because the prior art usually uses a constant current to turn on the power tube, the reverse recovery current of the body diode is greatly increased, resulting in an excessively high voltage from the drain to the source of the power tube, thereby greatly increasing the risk of the power tube being broken down and burned.

[0065] In view of this, the technical solution of the present invention provides a new driving method for driving a power tube.

[0066] in, Figure 2 The process of the driving method provided by the technical solution of the present invention is Figure 1 . Figure 3 It is a waveform diagram of various parameters of a power tube turned on by the driving method provided by the technical solution of the present invention.

[0067] Please refer to Figure 2 and Figure 3 The technical solution of the present invention provides a driving method for driving a power tube, the method comprising the following steps:

[0068] S11: Determine whether the power tube is turned on or off; if it is turned on, jump to S12; if it is turned off, jump to S15.

[0069] S12: Outputting the first on-current IG1st to the gate of the power tube.

[0070] S13: After the gate-source voltage of the power tube rises to the threshold voltage Vth, the first on-current IG1st is reduced to the second on-current IG2nd to reduce the reverse recovery current of the body diode corresponding to the power tube.

[0071] S14: after the gate-source voltage of the power tube rises from the threshold voltage Vth to the Miller voltage Vmiller, increasing the second on-current IG2nd to the third on-current IG3rd until the power tube is fully turned on.

[0072] S15: The gate of the power tube outputs a first turn-off current until the power tube is completely turned off.

[0073] Through the above technical means, the technical solution of the present invention greatly improves the safety of the power tube during the conduction process. The specific reasons are as follows:

[0074] It can be known from the above description that in the second stage of the power tube being turned on, the conduction current acting on the gate of the power tube will flow into the negative electrode of the body diode through the drain of the power tube, thereby increasing the reverse recovery current of the body diode. Therefore, the technical solution of the present invention intentionally reduces the first conduction current IG1st to the second conduction current IG2nd in the second stage of the power tube being turned on, so as to reduce the current flowing into the body diode in this stage, thereby reducing the reverse recovery current of the body diode, thereby avoiding the risk of the power tube being burned and broken down due to overshoot, and greatly improving the safety of the power tube during the conduction process.

[0075] It should be noted that the specific size of the second on-current IG2nd can be selected according to the specific size, type and withstand voltage of the power tube, and is not limited here. However, regardless of the specific size, type and withstand voltage of the power tube, the second on-current IG2nd is smaller than the constant current value used in the prior art to drive the same type of power tube.

[0076] In order to make the above-mentioned objects, features and beneficial effects of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0077] As a specific implementation, after increasing the second conduction current IG2nd to the third conduction current IG3rd in S14, the method further includes:

[0078] After the drain-source voltage of the power tube drops to zero, the third conduction current IG3rd is increased to a fourth conduction current. The first conduction current IG1st is set to be greater than the third conduction current IG3rd, and the third conduction current IG3rd is approximately equal to the constant current value of the same power tube in the prior art.

[0079] The beneficial effect of this implementation is: by setting the first conduction current IG1st and the fourth conduction current to be greater than the third conduction current IG3rd, the rate of the power tube in the first and fourth stages of conduction is accelerated, thereby improving the conduction efficiency of the power tube while ensuring the conduction safety of the power tube.

[0080] It should be noted that the reason for not increasing the third on-current IG3rd is that during the third stage of the power tube conduction, i.e., the Miller platform period, the drain-source voltage of the power tube will decrease to zero. If the on-current in this stage is too large, the Miller platform period will be shortened, causing the drain-source voltage of the power tube to decrease too quickly and generate an excessively large spike voltage, thereby greatly increasing the risk of the power tube being broken down.

[0081] As a supplementary explanation, the first on-current IG1st can be set to 2-3 times the constant current value of the same power tube in the prior art. Of course, the first on-current IG1st can also be set to different sizes according to requirements. The fourth on-current can also be set to 2-3 times the constant current value of the same power tube in the prior art. Of course, the fourth on-current can also be set to different sizes according to requirements. However, the first on-current IG1st and the fourth on-current are both greater than the constant current value of the same power tube in the prior art.

[0082] Figure 4 Schematic diagram of the circuit structure of the driving circuit provided by the embodiment of the present invention Figure 1 . Figure 5It is a conduction waveform diagram of the driving circuit provided by an embodiment of the present invention.

[0083] Before describing the working process of turning on the power tube by the driving method provided in the embodiment of the present invention, an example is first given of a driving circuit for driving the power tube to turn on and a control method thereof:

[0084] Please refer to Figure 3 , Figure 4 and Figure 5 , the driving circuit for driving the power tube to conduct includes: a first PMOS tube M1, a second PMOS tube M2, a third PMOS tube M3 and a fourth PMOS tube M4; the source of the first PMOS tube M1, the source of the second PMOS tube M2, the source of the third PMOS tube M3 and the source of the fourth PMOS tube M4 are all connected to the power supply voltage; the drain of the first PMOS tube M1, the drain of the second PMOS tube M2, the drain of the third PMOS tube M3 and the drain of the fourth PMOS tube M4 are all connected to the gate of the power tube.

[0085] In the diagram where the power tube is turned on, both the first PMOS tube M1 and the second PMOS tube M2 are turned on, and the driving circuit outputs the first on-current IG1st.

[0086] In the second stage of power tube conduction, the first PMOS tube M1 is turned off, and only the second PMOS tube M2 is turned on, and the driving circuit outputs the second conduction current IG2nd.

[0087] In the third stage when the power tube is turned on, the third PMOS tube M3 is also turned on, and the driving circuit outputs the third conduction current IG3rd.

[0088] In the fourth stage when the power tube is turned on, the fourth PMOS tube M4 is also turned on, and the driving circuit outputs a fourth conduction current.

[0089] The following Figure 4 and Figure 5 Taking the embodiment shown as an example, the working process of turning on the power tube by the driving method provided in the embodiment of the present invention is described:

[0090] Please refer to Figure 2 , Figure 3 , Figure 4 and Figure 5 , the first stage of power tube conduction: the first PMOS tube M1 and the second PMOS tube M2 are both turned on, the driving circuit outputs the first conduction current IGlst to the gate of the power tube. The gate-source voltage of the power tube rises from zero to the threshold voltage Vth.

[0091] The second stage of the power tube conduction: the first PMOS tube M1 is turned off, and only the second PMOS tube M2 is turned on. The output current of the drive circuit is reduced to the second conduction current IG2nd and output to the gate of the power tube. The gate-source voltage of the power tube rises from the threshold voltage Vth to the Miller voltage Vmiller. The power tube starts to carry current, and its drain-source current rises from zero to the peak value, and then decreases from the peak value to a constant maximum value.

[0092] The third stage of the power tube being turned on: the third PMOS tube M3 is also turned on, the output current of the drive circuit increases to the third conduction current IG3rd, and is output to the gate of the power tube. The gate-source voltage of the power tube is stabilized at the Miller voltage Vmiller. The drain-source voltage of the power tube decreases from a constant value to zero.

[0093] The fourth stage of power tube conduction: the fourth PMOS tube M4 is also turned on, the output current of the drive circuit increases to the fourth conduction current, and is output to the gate of the power tube. The gate-source voltage of the power tube rises from the Miller voltage Vmiller to a constant maximum value, and the power tube is fully turned on.

[0094] Figure 6 The process of the driving method provided by the technical solution of the present invention is Figure 2 . Figure 7 It is a waveform diagram of various parameters of the power tube turned off by the driving method provided by the technical solution of the present invention.

[0095] Please refer to Figure 6 and Figure 7 As a specific implementation, the method for shutting down the power tube includes the following steps in addition to S15:

[0096] S161: The gate of the power tube outputs a second turn-off current IG2.

[0097] S162: After the gate-source voltage of the power tube drops to the Miller voltage Vmiller, the second turn-off current IG2 is reduced to a third turn-off current IG3.

[0098] S163: After the gate-source voltage of the power tube drops to the threshold voltage Vth, the third turn-off current IG3 is increased to a fourth turn-off current IG4 until the power tube is completely turned off.

[0099] It should be noted that the third shutdown current IG3 and the first shutdown current can be set to the same current. Of course, the third shutdown current IG3 and the first shutdown current can also be set to be different. However, it is necessary to set the second shutdown current IG2 and the fourth shutdown current IG4 to be greater than the first shutdown current, and the first shutdown current is set to a constant current value for shutting down the same type of power tube in the prior art.

[0100] This implementation has the beneficial effect that since the second shutdown current IG2 and the fourth shutdown current IG4 are both greater than the third shutdown current IG3, the rates of the power tube at different stages during the shutdown process are accelerated, thereby improving the shutdown efficiency of the power tube.

[0101] It should be noted that the reason for not increasing the third turn-off current IG3 is similar to the reason for not increasing the third turn-on current IG3rd: during the Miller platform when the power tube is turned off, the drain-source voltage of the power tube will increase from zero to the maximum value. If the turn-off current at this stage is too large, the drain-source voltage of the power tube will increase too fast and generate an excessive spike voltage, thereby greatly increasing the risk of the power tube being broken down. During the period when the gate-source voltage of the power tube drops from the Miller voltage Vmiller to the threshold voltage Vth, the drain current of the power tube will decrease from the maximum value to zero. If the turn-off current at this stage is too large, the drain current of the power tube will decrease too fast and generate an excessive spike current, thereby greatly increasing the risk of the power tube being broken down.

[0102] As a supplementary explanation, the second shutdown current IG2 can be set to 2-3 times the constant current value of the same power tube in the prior art. Of course, the second shutdown current IG2 can also be set to different sizes according to requirements. The fourth shutdown current IG4 can also be set to 2-3 times the constant current value of the same power tube in the prior art. Of course, the fourth shutdown current IG4 can also be set to different sizes according to requirements. However, the second shutdown current IG2 and the fourth shutdown current IG4 are both greater than the constant current value of the same power tube in the prior art.

[0103] Figure 8 Schematic diagram of the circuit structure of the driving circuit provided by the embodiment of the present invention Figure 2 . Fig. 9 It is a shutdown waveform diagram of the driving circuit provided by an embodiment of the present invention.

[0104] Before describing the working process of shutting down the power tube by the driving method provided in the embodiment of the present invention, an example is first given of a driving circuit and a control method for shutting down the power tube:

[0105] Please refer to Figure 8 and Fig. 9, the driving circuit for driving the power tube to turn off includes: a first NMOS tube M5, a second NMOS tube M6, a third NMOS tube M7 and a fourth NMOS tube M8; the source of the first NMOS tube M5, the source of the second NMOS tube M6, the source of the third NMOS tube M7 and the source of the fourth NMOS tube M8 are all connected to the ground end; the drain of the first NMOS tube M5, the drain of the second NMOS tube M6, the drain of the third NMOS tube M7 and the drain of the fourth NMOS tube M8 are all connected to the gate of the power tube.

[0106] In the first stage of shutting down the power tube: the first NMOS tube M5 and the second NMOS tube M6 are both turned on, and the driving circuit controls the gate of the power tube to output the second shut-down current IG2.

[0107] In the second stage of shutting down the power tube: the second NMOS tube M6 is turned off, the third NMOS tube M7 is also turned on, and the driving circuit controls the gate of the power tube to output a third shut-down current IG3.

[0108] In the third stage of shutting down the power tube: the fourth NMOS tube M8 is also turned on, and the driving circuit controls the gate of the power tube to output a fourth shut-down current IG4.

[0109] The following Figure 8 and Fig. 9 Taking the embodiment shown as an example, the working process of shutting down the power tube by the driving method provided in the embodiment of the present invention is described:

[0110] Please refer to Figure 6 , Figure 7 , Figure 8 and Fig. 9 , the first stage of power tube shutdown: the first NMOS tube M5 and the second NMOS tube M6 are both turned on, the drive circuit outputs the second shutdown current IG2 to the gate of the power tube. The gate-source voltage of the power tube decreases from a constant maximum value to the Miller voltage Vmiller.

[0111] The second stage of power tube shutdown: the second NMOS tube M6 is turned off, the third NMOS tube M7 is also turned on, and the current output by the gate of the power tube is controlled by the driving circuit to be reduced to the third shutdown current IG3. In the first sub-stage of the second stage, the gate-source voltage of the power tube is stabilized at the Miller voltage Vmiller, and the drain-source voltage of the power tube rises from zero to a constant maximum value. In the second sub-stage of the second stage, the gate-source voltage of the power tube is reduced from the Miller voltage Vmiller to the threshold voltage Vth, and the drain-source current of the power tube is reduced from the constant maximum value to zero.

[0112] The third stage of power tube shutdown: the fourth NMOS tube M8 is also turned on, and the driving circuit increases the current controlling the gate output of the power tube to the fourth shutdown current IG4. The gate-source voltage of the power tube decreases from the threshold voltage Vth to zero, and the power tube is completely shut down.

[0113] In summary, the driving method provided by the embodiment of the present invention, after the gate-source voltage of the power tube rises to the threshold voltage Vth, reduces the first on-current IG1st to the second on-current IG2nd to reduce the reverse recovery current of the body diode corresponding to the power tube, thereby avoiding overshoot of the power tube during the conduction process, thereby improving the conduction safety of the power tube.

[0114] Furthermore, by setting the first on-current IG1st and the fourth on-current to be greater than the third on-current IG3rd, the rate of the power tube in the first and fourth stages of conduction is accelerated, thereby improving the conduction efficiency of the power tube on the basis of ensuring the conduction safety of the power tube. At the same time, in the Miller platform stage of the power tube conduction, the on-current is reduced to avoid excessive peak voltage.

[0115] Furthermore, since the second turn-off current IG2 and the fourth turn-off current IG4 are both greater than the third turn-off current IG3, the rates of the power tube at different stages during the turn-off process are accelerated, thereby improving the turn-off efficiency of the power tube. At the same time, in the Miller platform stage and the Miller platform to the threshold voltage Vth stage when the power tube is turned off, the turn-off current is reduced to avoid excessive peak voltage and peak current.

[0116] Before describing another technical solution of the present invention, the problems existing in the prior art when driving the amplifier circuit are first described.

[0117] The amplifier circuit usually includes a high-side power tube and a low-side power tube, the drain of the high-side power tube is connected to the power supply voltage, the source of the high-side power tube is connected to the drain of the low-side power tube and serves as the output end of the amplifier circuit, and the source of the second power tube is connected to the ground end. When the amplifier circuit is driven, the high-side power tube and the low-side power tube are turned on alternately. If there is a phase mismatch between the driving signal of the high-side power tube and the driving signal of the low-side power tube, or one power tube is turned on in advance when the other power tube is not completely turned off due to the large size of the power tube, it is possible that the two power tubes are turned on at the same time to form a low-resistance path from the power supply to the ground, generating a large current, thereby burning the power device.

[0118] In order to avoid the above situation, the existing technology will add a dead time interval between the gate drive signals to ensure that the power tube on one side is completely turned off before the power tube on the other side is turned on. Then, the set fixed dead time may be affected by external environmental factors such as temperature and process, resulting in the fixed dead time being too large or too small. If the dead time is too long, it will cause serious nonlinear distortion; if the dead time is too short, it will increase the risk of the high-side power tube and the low-side power tube being turned on at the same time.

[0119] In view of this, the technical solution of the present invention also provides another driving method for driving an amplifying module, wherein the amplifying module includes a first power tube and a second power tube, the drain of the first power tube is connected to the power supply voltage, the source of the first power tube is connected to the drain of the second power tube and serves as the output end of the amplifying module, and the source of the second power tube is connected to the ground end.

[0120] Another driving method provided by the technical solution of the present invention comprises the following steps:

[0121] When the second power tube is turned off, detecting a second gate-source voltage of the second power tube;

[0122] When the second gate-source voltage of the second power tube is less than or equal to the threshold voltage, turning on the first power tube;

[0123] When the first power tube is turned off, detecting a first gate-source voltage of the first power tube;

[0124] When the first gate-source voltage of the first power tube is less than or equal to the threshold voltage, turning on the second power tube;

[0125] Wherein, turning on the first power tube and turning on the second power tube both include:

[0126] Outputting a first conduction current to the gate of the power tube to be driven;

[0127] After the gate-source voltage of the power tube to be driven rises to the threshold voltage, the first conduction current is reduced to a second conduction current, so as to reduce the reverse recovery current of the body diode corresponding to the power tube to be driven;

[0128] After the gate-source voltage of the power tube to be driven rises from the threshold voltage to the Miller voltage, the second conduction current is increased to a third conduction current until the power tube to be driven is fully turned on.

[0129] Through the above technical means, the technical solution of the present invention can adaptively control the dead time between the first power tube and the second power tube being alternately turned on, so as to avoid the influence of external environmental factors such as temperature and process. The specific reasons are as follows:

[0130] While the first power tube is turned off, a first gate-source voltage of the first power tube is detected. When the first gate-source voltage is less than or equal to the threshold voltage, the second power tube is turned on. While the second power tube is turned off, a second gate-source voltage of the second power tube is detected. When the second gate-source voltage is less than or equal to the threshold voltage, the first power tube is turned on.

[0131] Since the conduction of one power tube is anchored to the gate-source voltage of another power tube during the shutdown process, even if the power tube is affected by external environmental factors such as temperature and process, it can be ensured that the power tube to be turned on will be turned on when the other power tube is completely turned off, thereby effectively avoiding the simultaneous conduction of the first power tube and the second power tube. At the same time, because the conduction of the power tube and the shutdown of the other power tube establish a chain relationship, when the power tube is affected by external environmental factors such as temperature and process, it can also be ensured that the dead time between the conduction of the power tube and the shutdown of the other power tube is controlled in a reasonable range.

[0132] It should be noted that, since the technical means for turning on or off a single power tube in this technical solution is the same as that of the previous technical solution and the corresponding embodiment, the turning on or off of the power tube will not be described in detail.

[0133] As a specific implementation manner, the first power tube and the second power tube both include: NMOS tube.

[0134] The technical solution of the present invention also provides a driving circuit of an amplifier module. The amplifier module includes a first power tube Ma and a second power tube Mb, wherein the drain of the first power tube Ma is connected to a power supply voltage VCC, the source of the first power tube Ma is connected to the drain of the second power tube Mb and serves as the output end of the amplifier module, and the source of the second power tube Mb is connected to the ground end.

[0135] in, Fig.10 It is a circuit structure schematic diagram of a driving circuit of an amplifying module provided by the technical solution of the present invention.

[0136] Please refer to Fig.10 The driving circuit of the amplification module provided by the technical solution of the present invention includes:

[0137] A first driving module 10, the first driving module 10 is used to turn on or off the first power tube Ma according to the first control signal V1 and the driving method provided in the previous technical solution;

[0138] A second driving module 20, the second driving module 20 is used to turn on or off the second power tube Mb according to the second control signal V2 and the driving method provided in the previous technical solution;

[0139] A bootstrap module 30, the bootstrap module 30 is used to boost the output voltage of the amplifying module, and use the boosted output voltage as the supply voltage of the first driving module 10;

[0140] A logic control module 40 and a level shift module 50, wherein the logic control module 40 is used to receive a control square wave Va inputted from the outside, and output a first control signal V1 to the level shift module 50 according to the control square wave Va, wherein the level shift module 50 is used to perform level conversion on the first control signal V1 and output a second control signal V2 to the first driving module 10, and the logic control module 40 is also used to output the third control signal V3 to the second driving module 20 according to the control square wave Va;

[0141] A threshold detection module 60, the threshold detection module 60 is used to detect the first gate-source voltage of the first power tube Ma and output it to the logic control module 40, the threshold detection module 60 is also used to detect the second gate-source voltage of the second power tube Mb and output it to the logic control module 40;

[0142] The logic control module 40 is also used to output a second control signal V2 when the first power tube Ma is turned off, based on the first gate-source voltage being less than a threshold voltage Vth, so that the second driving module 20 controls the second power tube Mb to be turned on; the logic control module 40 is also used to output a first control signal V1 when the second power tube Mb is turned off, based on the second gate-source voltage being less than a threshold voltage Vth, so that the first driving module 10 controls the first power tube Ma to be turned on.

[0143] The driving circuit and the corresponding amplifying module provided by the technical solution of the present invention are specifically applied in a class D power amplifier. Of course, the driving circuit provided by the technical solution of the present invention is also applicable to other circuit structures that require an amplifying module, which is not limited here.

[0144] The technical solution of the present invention further provides an electronic device, comprising a driving circuit of the amplification module.

[0145] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A driving method for driving a power tube, characterized in that: The method includes: When the power tube is turned on: Outputting a first conduction current to the gate of the power tube; After the gate-source voltage of the power tube rises to a threshold voltage, reducing the first on-current to a second on-current to reduce a reverse recovery current of a body diode corresponding to the power tube; After the gate-source voltage of the power tube rises from the threshold voltage to the Miller voltage, increasing the second conduction current to a third conduction current until the power tube is fully turned on; When the power tube is turned off: The gate of the power tube is made to output a first turn-off current until the power tube is completely turned off.

2. The driving method according to claim 1, characterized in that: The first conduction current is set to be greater than the third conduction current.

3. The driving method according to claim 2, characterized in that: After the second conduction current is increased to a third conduction current, the method further includes: After the drain-source voltage of the power tube drops to zero, the third conduction current is increased to a fourth conduction current.

4. The driving method according to claim 1, characterized in that: Also includes: causing the gate of the power tube to output a second turn-off current; After the gate-source voltage of the power tube drops to the Miller voltage, reducing the second off current to a third off current; After the gate-source voltage of the power tube drops to the threshold voltage, the third turn-off current is increased to a fourth turn-off current until the power tube is completely turned off.

5. A driving method for driving an amplification module, characterized in that: The amplification module includes a first power tube and a second power tube, the drain of the first power tube is connected to a power supply voltage, the source of the first power tube is connected to the drain of the second power tube and serves as the output end of the amplification module, and the source of the second power tube is connected to a ground end; the method includes: When the second power tube is turned off, detecting a second gate-source voltage of the second power tube; When the second gate-source voltage of the second power tube is less than or equal to the threshold voltage, turning on the first power tube; When the first power tube is turned off, detecting a first gate-source voltage of the first power tube; When the first gate-source voltage of the first power tube is less than or equal to the threshold voltage, turning on the second power tube; Wherein, turning on the first power tube and turning on the second power tube both include: Outputting a first conduction current to the gate of the power tube to be driven; After the gate-source voltage of the power tube to be driven rises to the threshold voltage, the first conduction current is reduced to a second conduction current, so as to reduce the reverse recovery current of the body diode corresponding to the power tube to be driven; After the gate-source voltage of the power tube to be driven rises from the threshold voltage to the Miller voltage, the second conduction current is increased to a third conduction current until the power tube to be driven is fully turned on.

6. The driving method according to claim 5, characterized in that: The first conduction current is set to be greater than the third conduction current.

7. The driving method according to claim 6, characterized in that: After the second conduction current is increased to a third conduction current, the method further includes: After the drain-source voltage of the power tube drops to zero, the third conduction current is increased to a fourth conduction current.

8. The driving method according to claim 5, characterized in that: The first power tube and the second power tube both include: NMOS tube.

9. A driving circuit of an amplification module, characterized in that: The amplification module includes a first power tube and a second power tube, the drain of the first power tube is connected to the power supply voltage, the source of the first power tube is connected to the drain of the second power tube and serves as the output end of the amplification module, and the source of the second power tube is connected to the ground end. The driving circuit includes: A first driving module, the first driving module is used to turn on or off the first power tube according to the driving method according to any one of claims 1 to 4 according to a first control signal; A second driving module, the second driving module is used to turn on or off the second power tube according to the driving method according to any one of claims 1 to 4 according to a second control signal; A bootstrap module, the bootstrap module is used to boost the output voltage of the amplifying module and use the boosted output voltage as the power supply voltage of the first driving module; A logic control module and a level shift module, wherein the logic control module is used to receive a control square wave input from the outside, and output a first control signal to the level shift module according to the control square wave, the level shift module is used to perform level conversion on the first control signal and output a second control signal to the first driving module, and the logic control module is also used to output a third control signal to the second driving module according to the control square wave; A threshold detection module, the threshold detection module is used to detect a first gate-source voltage of the first power tube and output it to the logic control module, the threshold detection module is also used to detect a second gate-source voltage of the second power tube and output it to the logic control module; The logic control module is also used to output a second control signal when the first power tube is turned off, based on the first gate-source voltage being less than a threshold voltage, so that the second driving module controls the second power tube to be turned on; the logic control module is also used to output a first control signal when the second power tube is turned off, based on the second gate-source voltage being less than a threshold voltage, so that the first driving module controls the first power tube to be turned on.

10. An electronic device, characterized in that: A driving circuit comprising the amplification module as claimed in claim 9.

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