Adaptive driving method and device for switching power supply and switching power supply

Abstract

The invention discloses a self-adaptive driving method and device of a switching power supply and the switching power supply, and relates to the technical field of power electronics. In the scheme, a plurality of working parameters of the switching power supply under the current working condition are obtained; determining target rise time corresponding to the current working condition according to the plurality of working parameters; and controlling the driving voltage of the power switch to rise from the initial value to the preset conduction value within the target rise time so as to conduct the power switch. Therefore, accurate control of the power switch of the switching power supply is realized by acquiring the plurality of working parameters under the current working condition, determining the target rise time and controlling the conduction of the power switch, and balance of temperature rise and secondary side stress of a device under all working conditions can be realized, so that the service life of the switching power supply is prolonged, and the reliability and the stability of the switching power supply are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power electronics, and in particular to a switching power supply adaptive driving method, device and switching power supply. Background Art

[0002] The secondary rectifier circuit of the switching power supply converts the AC voltage generated by the transformer into a DC voltage on the secondary side. However, when the rectifier is in operation, the secondary inductor will generate electromagnetic induction, causing instability in the current waveform and also generating a reverse voltage spike Vspike. Vspike is a major factor affecting the voltage stress of the secondary rectifier. If Vspike is too high, it will increase the switching loss of the rectifier and increase the reverse recovery current, thus affecting the efficiency and life of the device. However, if you want to reduce Vspike, the surface temperature of the power device will rise quickly. In other words, there is often a contradiction in solving these two problems.

[0003] At present, the main solution for traditional silicon (Si) devices is to reduce the turn-on speed of the power switch and reduce Vspike by increasing the series gate resistance, thereby reducing the voltage stress of the rectifier tube.

[0004] Compared with traditional silicon (Si) devices, gallium nitride (GaN) power semiconductor devices have greater temperature tolerance and are more suitable for high power density and high frequency applications. However, they also have dynamic on-resistance caused by the current collapse effect. During use, the characteristics of their dynamic on-resistance may cause the resistance to increase, resulting in additional power consumption, causing serious temperature rise of the device, thereby affecting the device efficiency and life.

[0005] In addition, in AC-DC systems, there are generally complex working conditions, such as wide input voltage range, wide output voltage range, multiple working modes, etc. In particular, for the dynamic on-resistance of gallium nitride (GaN) power semiconductors, the fixed driving method of adding series gate resistance cannot take into account the above-mentioned rectifier voltage stress and power device temperature rise, and the balance between the two under different environmental conditions.

[0006] In summary, providing a driving method to achieve a balance between device temperature rise and secondary side stress under all operating conditions is a technical problem that technical personnel in this field urgently need to solve. Summary of the invention

[0007] The purpose of the present invention is to provide a switching power supply adaptive driving method, device and switching power supply, which can achieve precise control of the power switch of the switching power supply by acquiring multiple working parameters under the current working conditions, determining the target rise time and controlling the conduction of the power switch, and can achieve a balance between the device temperature rise and the secondary side stress under all working conditions, thereby extending the service life of the switching power supply and improving its reliability and stability.

[0008] In order to solve the above technical problems, the present invention provides a switching power supply adaptive driving method, comprising:

[0009] Acquire multiple operating parameters of the switching power supply under current working conditions;

[0010] According to the plurality of operating parameters, selecting a target rise time required for turning on the power switch corresponding to the current operating condition;

[0011] The driving voltage of the power switch is controlled to increase from an initial value to a preset turn-on value within the target rise time, so as to turn on the power switch.

[0012] Preferably, the power switch is a gallium nitride power switch.

[0013] Preferably, the preset conduction value is a threshold voltage of the power switch.

[0014] Preferably, the operating parameters at least include an input voltage of the switching power supply and / or a load value connected to the switching power supply.

[0015] Preferably, determining the target rise time corresponding to the current working condition according to the plurality of working parameters includes:

[0016] Determining whether the input voltage of the switching power supply is less than a preset input voltage;

[0017] If it is less than the preset input voltage, selecting the target rise time as the first rise time;

[0018] If it is not less than the preset input voltage, selecting the target rise time as the second rise time;

[0019] The first rise time is less than the second rise time.

[0020] Preferably, before selecting the target rise time as the second rise time, the method further includes:

[0021] Determining whether a load value connected to the switch power supply is greater than a preset load threshold;

[0022] If it is greater than the preset load threshold, selecting the target rise time as the second rise time;

[0023] If it is not greater than the preset load threshold, selecting the target rise time as the third rise time;

[0024] The first rise time is less than the second rise time and less than the third rise time.

[0025] Preferably, the switching power supply includes a voltage divider circuit, the input end of the voltage divider circuit is connected to the output end of the auxiliary winding of the switching power supply, and when the operating parameter includes an input voltage, the input voltage of the switching power supply is obtained in the following manner:

[0026] The input voltage of the switching power supply is determined by collecting the voltage of the voltage divider circuit.

[0027] Preferably, the voltage divider circuit is a resistor voltage divider circuit or a winding voltage divider circuit.

[0028] Preferably, when the operating parameter includes a load value connected to the switching power supply, the load value connected to the switching power supply is obtained in the following manner:

[0029] The output power of the switching power supply is acquired, and a load value of the switching power supply is determined according to the output power.

[0030] Preferably, obtaining the output power of the switching power supply includes:

[0031] A feedback voltage outputted by a feedback pin of the switching power supply is obtained, and the output power of the switching power supply is determined according to the feedback voltage.

[0032] Preferably, obtaining the output power of the switching power supply includes:

[0033] The valley number of the resonant waveform corresponding to the conduction phase of the primary power switch is determined, and the output power is determined according to the valley number.

[0034] Preferably, obtaining the output power of the switching power supply includes:

[0035] The output current of the primary side of the switching power supply is obtained, and the output power is determined according to the output current.

[0036] Preferably, the switching power supply includes a driving circuit, the driving circuit includes a driving capacitor, a first driving switch and a second driving switch, the first end of the driving capacitor is grounded, the second end of the driving capacitor is connected to the control end of the first driving switch, the first end of the first driving switch is connected to the power supply, the second end of the first driving switch is respectively connected to the control end of the power switch and the first end of the second driving switch, and the second end of the second driving switch is grounded;

[0037] Controlling the driving voltage of the power switch to rise from an initial value to a preset conduction value within the target rise time includes:

[0038] By charging and discharging the driving capacitor, the voltage of the driving capacitor is adjusted so that the voltage of the driving capacitor rises from the initial value to the first voltage value within the target rising time, so that the first driving switch is turned on;

[0039] When the voltage of the driving capacitor reaches the first voltage value, the second driving switch is turned off, and when the voltage of the control terminal of the power switch reaches the preset conduction value, the power switch is turned on.

[0040] In order to solve the above technical problems, the present invention provides a switching power supply adaptive driving device, comprising:

[0041] A detection circuit, used to obtain multiple operating parameters of the switching power supply under current working conditions;

[0042] An adjustment circuit, used for selecting a target rise time required for turning on the power switch corresponding to the current working condition according to the plurality of working parameters;

[0043] The driving circuit is used to control the driving voltage of the power switch to rise from an initial value to a preset turn-on value within the target rise time, so as to turn on the power switch.

[0044] Preferably, the driving circuit comprises a driving capacitor, a first driving switch and a second driving switch, the first end of the driving capacitor is grounded, the second end of the driving capacitor is connected to the control end of the first driving switch, the first end of the first driving switch is connected to a power supply, the second end of the first driving switch is respectively connected to the control end of the power switch and the first end of the second driving switch, the second end of the second driving switch is grounded, and the conduction state of the first driving switch is opposite to the conduction state of the second driving switch;

[0045] The driving circuit is specifically used to control the voltage of the driving capacitor to rise from the initial value to the first voltage value within the target rising time;

[0046] When the voltage of the driving capacitor reaches the first voltage value, the first driving switch is turned on, the second driving switch is turned off, and the voltage of the control terminal of the power switch reaches the preset turn-on value, and the power switch is turned on.

[0047] Preferably, the driving circuit further includes:

[0048] A charging regulation circuit, one end of which is connected to the second end of the driving capacitor, and the other end of which is connected to the adjustment circuit;

[0049] The charging regulation circuit is used to adjust its own working state according to the target rise time selected by the adjustment circuit to provide the target charging current to the driving capacitor so that the voltage of the driving capacitor reaches the first voltage value within the target rise time;

[0050] The target charging current is negatively correlated with the target rise time.

[0051] Preferably, the charging regulation circuit includes:

[0052] A switch circuit, N constant current sources and M auxiliary capacitors, N≥1, M≥0, N+M≥2, and N and M are both integers;

[0053] The first end of the switch circuit is connected to all the constant current sources, the second end of the switch circuit is connected to all the auxiliary capacitors, and the third end of the switch circuit is connected to the second end of the driving capacitor;

[0054] The constant current source is used to provide a constant current;

[0055] The switch circuit is used to adjust its own path state according to the target rise time to select a first target number of constant current sources and a second target number of auxiliary capacitors to access the circuit, so that the first target number of constant current sources charges the drive capacitor and the second target number of auxiliary capacitors;

[0056] The first target number is at least 1, the second target number is at least 0, the first target number is negatively correlated with the target rise time, and the second target number is positively correlated with the target rise time.

[0057] Preferably, when N>1 and M=0, the switch circuit includes:

[0058] Main switch, first switch circuit;

[0059] One end of the first switch circuit is connected to the output ends of the n constant current sources, the other end of the first switch circuit is respectively connected to the output ends of the other constant current sources except the n constant current sources and one end of the main switch, the other end of the main switch is respectively connected to the second end of the driving capacitor and the control end of the first driving switch, and the control end of the first switch circuit is connected to the adjustment circuit; N>n≥1, n is an integer;

[0060] The main switch is used to be turned on when charging the driving capacitor;

[0061] The first switch circuit is used to adjust its own path state to select a third target number of constant current source access circuits, where the first target number minus the third target number=Nn.

[0062] Preferably, when N=1 and M>0, the switch circuit includes:

[0063] Main switch, second switch circuit;

[0064] One end of the main switch is connected to all the constant current sources, one end of the second switch circuit is connected to the first ends of the m auxiliary capacitors, the other end of the second switch circuit is respectively connected to the first ends of the other auxiliary capacitors except the m auxiliary capacitors and the other end of the main switch, the second end of the drive capacitor and the control end of the first drive switch, the second ends of all the auxiliary capacitors are grounded, and the second end of the second switch circuit is connected to the adjustment circuit, M≥m>0, m is an integer;

[0065] The main switch is used to be turned on when charging the driving capacitor;

[0066] The second switch circuit is used to adjust its own path state to select a fourth target number of auxiliary capacitors to access the circuit, where the second target number minus the fourth target number=Mm.

[0067] Preferably, when N>1 and M>0, the switch circuit includes:

[0068] A main switch, a first switch circuit and a second switch circuit;

[0069] One end of the first switch circuit is connected to the output ends of the n constant current sources, the other end of the first switch circuit is respectively connected to the output ends of the other constant current sources except the n constant current sources and one end of the main switch, the other end of the main switch is respectively connected to the first end of the second switch circuit, the first ends of the other auxiliary capacitors except the m auxiliary capacitors, the second end of the driving capacitor and the control end of the first driving switch, the other end of the second switch circuit is connected to the m auxiliary capacitors, the second ends of all the auxiliary capacitors are grounded, and the control end of the first switch circuit and the control end of the second switch circuit are both connected to the adjustment circuit; N>n≥1, M≥m>0, m and n are integers;

[0070] The main switch is used to be turned on when charging the driving capacitor;

[0071] The first switch circuit is used to adjust its own path state to select a third target number of constant current source access circuits, where the first target number minus the third target number=Nn;

[0072] The second switch circuit is used to adjust its own path state to select a fourth target number of auxiliary capacitors to access the circuit, where the second target number minus the fourth target number=Mm.

[0073] Preferably, the first switch circuit comprises:

[0074] n controllable switches, corresponding one to one with the n constant current sources, each controllable switch is arranged between the output end of the constant current source corresponding to itself and one end of the main switch, and the control end of each controllable switch is connected to the adjustment circuit;

[0075] The driving circuit further includes:

[0076] A control circuit connected to at least one of the n controllable switches, wherein the control circuit comprises a first comparator, a second comparator, a NAND gate and an OR gate;

[0077] The first comparison voltage value is input to the positive input terminal of the first comparator, the preset conduction value is input to the negative input terminal of the first comparator and the positive input terminal of the second comparator, the second comparison voltage value is input to the negative input terminal of the second comparator, the output terminal of the first comparator and the output terminal of the second comparator are respectively connected to the two input terminals of the NAND gate, the output terminal of the NAND gate is connected to the first input terminal of the OR gate, the second input terminal of the OR gate is connected to the adjustment circuit, and the output terminal of the OR gate is connected to the control terminal of at least one controllable switch;

[0078] The first comparison voltage value is greater than the second comparison voltage value.

[0079] Preferably, the second switch circuit comprises:

[0080] m sub-switch circuits, m third clamping circuits, and m resistors, and the m sub-switch circuits, the m third clamping circuits, the m resistors, and the m auxiliary capacitors correspond one to one;

[0081] The first end of each of the sub-switch circuits is respectively connected to the first end of the auxiliary capacitor corresponding to itself, the first end of the third clamping circuit corresponding to itself, and the first end of the resistor corresponding to itself. The second end of each of the auxiliary capacitors and the second end of each of the third clamping circuits are grounded. The second end of each of the resistors inputs a preset clamping voltage. The control end of each of the sub-switch circuits is connected to the adjustment circuit.

[0082] Preferably, the driving circuit further includes:

[0083] NOT gate, a third driving switch, a first clamping circuit, a second clamping circuit and a PWM output module;

[0084] The first output end of the PWM output module is respectively connected to the input end of the NOT gate and the control end of the third drive switch, the output end of the NOT gate is connected to the control end of the main switch, the first end of the third drive switch is respectively connected to the first end of the first clamp circuit, the first end of the second clamp circuit, the second end of the drive capacitor and the control end of the first drive switch, the second end of the third drive switch, the second end of the first clamp circuit and the second end of the second clamp circuit are all grounded, and the second output end of the PWM output module is connected to the control end of the second drive switch;

[0085] The signal levels outputted by the two output terminals of the PWM output module are opposite.

[0086] In order to solve the above technical problem, the present invention provides a switching power supply, including the switching power supply adaptive driving device as described above.

[0087] The present invention provides a switching power supply adaptive driving method, device and switching power supply, which relate to the field of power electronics technology. In this scheme, multiple operating parameters of the switching power supply under the current working conditions are obtained; the target rise time corresponding to the current working conditions is determined according to the multiple operating parameters; the driving voltage of the power switch is controlled to rise from the initial value to the preset conduction value within the target rise time to turn on the power switch. It can be seen that in the present invention, by obtaining multiple operating parameters under the current working conditions, determining the target rise time and controlling the power switch to be turned on, the power switch of the switching power supply can be precisely controlled, and the balance of device temperature rise and secondary side stress under all working conditions can be achieved, thereby extending the service life of the switching power supply and improving its reliability and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0088] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the prior art and the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0089] Figure 1 A circuit block diagram of a switching power supply provided by the present invention;

[0090] Figure 2 A schematic diagram of voltage stress of a secondary rectifier tube provided by the present invention;

[0091] Figure 3 A schematic diagram of conduction in a QR mode provided by the present invention;

[0092] Figure 4 A schematic diagram of Vspike during peak conduction provided by the present invention;

[0093] Figure 5 A schematic diagram of Vspike provided by the present invention when conducting in the valley;

[0094] Figure 6 A schematic diagram of a flow chart of a switching power supply driving method provided by the present invention;

[0095] Figure 7 A schematic diagram of the driving rise time of the power switch provided by the present invention;

[0096] Figure 8 An internal schematic diagram of a primary side controller provided by the present invention;

[0097] Fig. 9 A schematic diagram of a switch circuit for adjusting only the number of constant current sources provided by the present invention;

[0098] Fig.10 A schematic diagram of a switch circuit for adjusting only the number of auxiliary capacitors provided by the present invention;

[0099] Fig.11 A schematic diagram of a switch circuit for simultaneously adjusting the number of constant current sources and auxiliary capacitors provided by the present invention;

[0100] Fig.12 A schematic diagram of another switch circuit for simultaneously adjusting the number of constant current sources and auxiliary capacitors provided by the present invention;

[0101] Fig.13 A schematic diagram of the timing of each device in the driving module provided by the present invention;

[0102] Fig.14 A schematic diagram of the circuit and signal timing of the Non-Overlap module provided by the present invention;

[0103] Fig.15 A circuit diagram of a Level-Shift module provided by the present invention;

[0104] Fig.16 A circuit diagram of the Clamp module provided by the present invention;

[0105] Fig.17 A schematic diagram of an implementation method of a Line Sense module provided by the present invention;

[0106] Fig.18 A schematic diagram of another implementation method of the Line Sense module provided by the present invention;

[0107] Fig.19 A schematic diagram of an implementation method of Load Sense provided by the present invention;

[0108] Fig. 20 A schematic diagram of another implementation method of Load Sense provided by the present invention;

[0109] Fig.21 A schematic diagram of a dynamic resistance of gallium nitride provided by the present invention;

[0110] Fig. 22 A schematic diagram of the influence of gate resistance on dynamic resistance is provided for the present invention. DETAILED DESCRIPTION

[0111] The core of the present invention is to provide a switching power supply adaptive driving method, device and switching power supply. By acquiring multiple working parameters under the current working conditions, determining the target rise time and controlling the conduction of the power switch, precise control of the power switch of the switching power supply can be achieved, and the balance between the device temperature rise and the secondary side stress under all working conditions can be achieved, thereby extending the service life of the switching power supply and improving its reliability and stability.

[0112] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0113] Before describing the present invention, the principle of the switching power supply is first explained. Figure 1 As shown, Figure 1 A circuit block diagram of a switching power supply provided by the present invention, the switching power supply mainly includes a rectifier bridge DB for converting AC power into DC power, an input capacitor Cbulk for smoothing rectified voltage fluctuations, a switch for controlling the primary power switch Qp, a primary controller for realizing changes in the transformer magnetic field, a primary power switch Qp, a transformer, a secondary rectifier for transmitting output electric energy to the output capacitor Cout and finally providing it to the load for use, and an output capacitor Cout, wherein the secondary rectifier can be a Schottky diode or a MOS tube, which is not limited in the present invention.

[0114] like Figure 2 As shown, Figure 2A schematic diagram of the voltage stress of a secondary rectifier tube provided by the present invention is shown in detail. Specifically, during the operation of the switching power supply, the secondary voltage stress of the rectifier tube on the secondary side is: Vds=Vout+Ns / NpxVin+Vspike, wherein Np is the primary turns of the transformer, Ns is the secondary turns of the transformer, Vout is the output voltage, Vin is the input voltage, and the rectifier tube reverse voltage spike Vspike (caused by the resonance of the transformer through the secondary leakage inductance, the equivalent capacitance of the rectifier tube, and the secondary stray capacitance under the influence of the rectifier tube's dv / dt (the voltage change rate of the transformer connecting the rectifier tube end) and the diode reverse recovery current (only in continuous mode)). If the voltage stress of the secondary rectifier tube is too high, it will lead to: a) a sharp increase in the switching loss of the rectifier tube, an increase in the temperature rise of the device, and a decrease in efficiency; b) a sharp increase in the reverse recovery current of the rectifier tube, an increase in loss, and a decrease in efficiency; c) in order to meet the derating specifications, a rectifier tube with a higher withstand voltage is used, which increases the cost.

[0115] In the design practice based on traditional silicon devices, the turn-on speed of the primary MOS is generally slowed down by increasing the series gate resistance; the slower the turn-on speed of the primary MOS, the slower the primary Drain voltage drops, thereby reducing the voltage change rate of the transformer rectifier tube end to reduce Vspike. However, for gallium nitride (GaN) power semiconductor devices, due to their material properties, they can operate at faster switching frequencies and have a larger temperature tolerance, making them more suitable for high-frequency, high-power density applications. Fig.21 As shown, Fig.21 This is a schematic diagram of the dynamic resistance of gallium nitride provided by the present invention. It can be seen that the high drain-source voltage of gallium nitride in the off state causes the dynamic resistance to increase.

[0116] However, there are also a series of new problems in practical applications, among which the current collapse effect has the greatest impact. This effect is manifested as dynamic on-resistance in the specific parameters of the device. Fig. 22 As shown, Fig. 22The present invention provides a schematic diagram of the influence of gate resistance on dynamic resistance. The dynamic resistance of GaN is not monotonically related to the switching frequency. The switching frequency design mainly considers the system volume / power. The highest switching frequency of USB PD power supplies on the market is mostly designed at 100KHz~120KHz. Increasing the duty cycle is conducive to reducing the dynamic resistance of GaN, but the maximum duty cycle design is subject to multiple factors (primary side stress, secondary side stress, working mode), and the duty cycle is related to the working condition, and there is little room for adjustment. In applications, it is generally recommended to use a GaN driving voltage of 5~6V, which not only ensures that the driving voltage is much greater than the threshold voltage, but also avoids gate breakdown. The larger the gate series resistance, the longer the driving rise time when turned on, and the larger the GaN dynamic resistance. Therefore, the method of slowing down the opening speed of the primary power switch by connecting a gate resistor in series is not suitable for GaN. That is, due to the dynamic resistance of GaN, if the AC-DC system has complex working conditions (wide input voltage range, wide output voltage range, multiple working modes), it is difficult to achieve a balance between device temperature rise and secondary side stress under all working conditions through a simple driving method (only selecting a series gate resistor).

[0117] like Figure 3 As shown, Figure 3 A schematic diagram of conduction in a QR mode provided by the present invention. Specifically, the QR (Quasi-Resonant) mode uses the valley bottom of the resonant waveform to turn on the primary power switch to reduce the Vds at the turn-on moment of the power device. Under heavy load conditions, it is generally turned on at the first few valleys, which can significantly reduce Vds. Under light loads, due to the attenuation of the resonant waveform, the Vds corresponding to the subsequent valleys increases. When a power supply with a wide output voltage range outputs a low voltage, the amplitude of the resonant waveform decreases, and the Vds corresponding to all valleys is relatively high; therefore, for high input voltage or high output voltage, the system is suitable for using the QR mode, and the power tube is turned on at the valley bottom of the resonant waveform, which can effectively reduce switching losses; under low input voltage and low output voltage, the system is suitable for using CCM (Continual Current Mode). The switching frequency is highest under heavy load, which can effectively reduce transformer current stress.

[0118] like Figure 4 As shown, Figure 4 A schematic diagram of Vspike at the peak conduction provided by the present invention; in DCM (Discontinuous Conduction Mode, discontinuous current mode), if the primary GaN is turned on at the peak of the primary resonance waveform, the voltage difference between the transformer and the rectifier tube before and after the turn-on maximum( =Ns / NpxVin+Vout), at this time, the voltage change rate of the rectifier tube is the largest, and Vspike is the largest.

[0119] like Figure 5 As shown, Figure 5 A schematic diagram of Vspike during valley conduction provided by the present invention; under heavy load in QR mode, the primary GaN is turned on at the bottom of the (first few) primary resonance waveforms, and the voltage difference between the transformer and the rectifier tube before and after the turn-on Minimum( =Ns / NpxVin-Vout), at this time, the voltage change rate of the rectifier tube is the smallest and Vspike is the smallest.

[0120] The amplitude of the resonant waveform decays under light load. When the primary side GaN is turned on, the voltage difference between the transformer and the rectifier tube before and after the turn-on When it rises to Ns / NpxVin, the voltage change rate of the rectifier tube is medium, and Vspike is medium (such as Figure 2 At this time, the turn-on speed of the primary GaN can be slowed down, the voltage change rate of the rectifier tube can be reduced again, and Vspike can be reduced to the minimum.

[0121] Under CCM, due to the dynamic resistance effect of GaN, the turn-on speed of the primary GaN needs to be accelerated. When the primary GaN is turned on, the voltage difference between the transformer and the rectifier tube before and after the turn-on is maximum( =Ns / NpxVin+Vout); at this time, the voltage change rate of the rectifier tube is the largest, and the di / dt during the reverse recovery current falling time will also generate voltage on the secondary leakage inductance (including stray inductance), and the superimposed Vspike is the largest. In order to reduce Vds, it is necessary to avoid the system working in CCM under high Vin conditions.

[0122] In the prior art, there is only one driving waveform for controlling GaN, and correspondingly, there is only a single rise time when GaN is turned on. Even if the rise time can be adjusted by changing the external series resistor during design, it is impossible to set different rise times according to different working conditions, and the secondary side voltage stress and device temperature stress cannot be balanced.

[0123] In order to solve the above technical problems, the design idea of ​​the switching power supply driving method provided by the present invention is to control the on-time of the power switch by real-time monitoring and analysis of the working parameters of the switching power supply, combined with the setting of the target rise time, so as to optimize the circuit design and working efficiency of the system. Its technical principle is that by controlling the on-time of the power switch, the reverse voltage spike generated by the secondary inductance can be effectively reduced, the device stress and switching loss of the rectifier tube can be reduced, and the response speed and stability of the system can be improved.

[0124] like Figure 6 As shown, Figure 6 A schematic flow chart of a switching power supply driving method provided by the present invention, the method comprising:

[0125] S11: Acquire multiple operating parameters of the switching power supply under the current working condition;

[0126] Specifically, the working parameters of the switching power supply are the basis for ensuring the stable operation of the switching power supply, and are also the basic parameters that reflect the current working conditions of the switching power supply. Based on the idea of ​​multi-parameter control, by obtaining multiple working parameters of the switching power supply under the current working conditions, the current working conditions of the switching power supply can be understood more accurately, and then the working state of the switching power supply and the requirements for achieving the target output waveform can be determined, so as to further control the on and off time of the switching power supply.

[0127] It should be noted that multiple key operating parameters of the switching power supply under current working conditions, such as input voltage, output voltage, output current, power factor, load capacity, etc., can be obtained through sensors or monitoring systems. The acquisition method can be real-time acquisition.

[0128] As a preferred embodiment, the operating parameters at least include the input voltage of the switching power supply and / or the load value connected to the switching power supply. Among them, the input voltage directly affects the setting of the driving voltage. In the switching power supply, the driving voltage needs to be within a specific range to ensure that the power switch is turned on normally. Changes in the input voltage will cause the required driving voltage to be adjusted to ensure that the power switch can provide sufficient current when turned on, thereby affecting the output power. If the input voltage is low, it may take a longer rise time for the driving voltage to reach the preset value; conversely, if the input voltage is high, the rise time may be shortened, thereby speeding up the turn-on speed of the power switch.

[0129] The load value determines the current that the power switch needs to carry. Changes in the load will cause changes in the power output of the power supply, which in turn affects the drive requirements of the switch. For example, when the load is heavy, the power switch needs a larger current to meet the load requirements, which may lead to higher requirements for the drive voltage and a longer rise time. Conversely, under light load conditions, the current required for the power switch to turn on is relatively small, so the target rise time can be shortened to improve the response speed of the system.

[0130] It can be seen that the input voltage and load value indirectly determine the target rise time by affecting the setting of the driving voltage and the conduction requirements of the power switch, thus playing a key role in the operation of the switching power supply. Therefore, by obtaining these working parameters in real time, the driving voltage of the power switch can be dynamically adjusted according to the actual working conditions to ensure that it can achieve the best conduction effect under different input voltage and load conditions, thereby improving the overall efficiency and reliability of the switching power supply.

[0131] S12: selecting a target rise time required for turning on a power switch corresponding to a current working condition according to a plurality of working parameters;

[0132] Specifically, the target rise time is an important operating parameter of the switching power supply, which can affect the stability, safety and efficiency of the switching power supply. By determining the target rise time corresponding to the current working condition, the working state of the switching power supply can be controlled more accurately, thereby improving the performance and efficiency of the switching power supply.

[0133] Specifically, after determining multiple operating parameters under the current working condition, this step determines the target rise time corresponding to the current working condition based on these parameters. This target rise time is based on the control requirements of the switching power supply and the system response speed. Generally speaking, in practical applications, in order to ensure the stability and reliability of the system, this target rise time can be adjusted within a certain range according to actual needs.

[0134] In this step, by determining the target rise time corresponding to the current working conditions, the working state of the switching power supply can be controlled more accurately, the performance and efficiency can be improved, and the energy consumption can be effectively reduced and energy can be saved.

[0135] S13: Controlling the driving voltage of the power switch to rise from an initial value to a preset turn-on value within a target rise time, so as to turn on the power switch.

[0136] The key to this step is to dynamically adjust the rise time of the driving voltage to adapt to different working conditions and environments, so as to effectively control the temperature rise of the power device while ensuring the voltage stress of the power switch. Specifically, the power switch is one of the important components of the switching power supply. By controlling the conduction time, the output voltage and output current of the switching power supply can be quickly increased, thereby ensuring the stable operation of the switching power supply under different working conditions. By adjusting the speed at which the driving voltage of the power switch reaches the threshold voltage, the voltage stress of the secondary rectifier tube and the temperature rise of the primary power switch can be improved.

[0137] By controlling the power switch in the switching power supply to turn on within the target rise time, the reverse voltage spike generated by the secondary inductance can be effectively reduced, and the device stress of the power switch can be reduced, thereby improving the efficiency and life of the system.

[0138] As a preferred embodiment, the power switch is a gallium nitride power switch. This choice is based on the significant advantages of gallium nitride power semiconductor devices in high temperature and high frequency applications, while also taking into account its unique challenges in dynamic on-resistance characteristics. Gallium nitride power switches have higher electron mobility and lower on-resistance, which enables them to perform well in high-frequency and high-power density applications. However, the dynamic on-resistance characteristics of gallium nitride devices may cause resistance to increase during the switching process, resulting in additional power consumption and temperature rise. This characteristic is particularly evident under complex operating conditions, such as wide input voltage range, wide output voltage range, and multiple operating modes.

[0139] As a preferred embodiment, the preset conduction value is the threshold voltage of the power switch. Specifically, the threshold voltage of the power switch refers to the minimum voltage at which the switch device starts to conduct under specific conditions so that the switch can conduct normally. The gallium nitride power switch has a low on-resistance and high efficiency, but its conduction characteristics depend on the magnitude of the input voltage. When the driving voltage is lower than the threshold voltage, the power switch cannot be fully turned on, which may cause unstable switch operation or increased losses. When the driving voltage reaches and remains above the threshold voltage, the power switch will be in the on state, allowing the current to pass smoothly, thereby effectively controlling the power output. Therefore, in this driving method, the preset conduction value is set to the threshold voltage to ensure that the power switch can work reliably under various operating conditions and achieve efficient power conversion and stable power supply performance.

[0140] In summary, the switching power supply driving method provided by the present invention achieves precise control of the power switch of the switching power supply by obtaining multiple working parameters under the current working conditions, determining the target rise time and controlling the conduction of the power switch. The switching power supply can achieve a balance between device temperature rise and secondary side stress under all working conditions, which not only avoids the voltage stress problem caused by excessive voltage spikes, but also effectively controls the temperature rise of power devices, thereby improving the overall efficiency and reliability of the system. This adaptive driving method is not only suitable for traditional silicon (Si) devices, but also particularly suitable for gallium nitride (GaN) power semiconductor devices with dynamic on-resistance characteristics, and can achieve better performance under complex working conditions.

[0141] Based on the above embodiments:

[0142] As a preferred embodiment, a target rise time corresponding to the current operating condition is determined based on multiple operating parameters, including: determining whether the input voltage of the switching power supply is less than a preset input voltage; if it is less than the preset input voltage, selecting the target rise time as the first rise time; if it is not less than the preset input voltage, selecting the target rise time as the second rise time; wherein the first rise time is less than the second rise time.

[0143] Specifically, in the operation of the switching power supply, the control of the rise time is crucial. If the rise time is too long, the temperature of the power switch will rise, affecting the stability and reliability of the circuit; if the rise time is too short, the voltage stress of the secondary rectifier tube will be high, affecting the reliability of the switching power supply. Therefore, how to determine a reasonable target rise time according to the current working conditions is an important issue in the design of the switching power supply.

[0144] Based on this technical problem, this embodiment provides a method for determining the target rise time according to the current working condition. The specific process is: determine the current working condition according to multiple working parameters; judge the magnitude relationship between the input voltage and the preset input voltage according to the current working condition; determine the target rise time as the first rise time or the second rise time according to the magnitude relationship to control the conduction of the power switch. Among them, the first rise time is shorter and is suitable for the case of lower input voltage; the second rise time is longer and is suitable for the case of higher input voltage.

[0145] That is, the core of this embodiment is to select a suitable rise time according to the magnitude relationship of the input voltage in the process of controlling the conduction of the power switch. By setting the difference between the first rise time and the second rise time, the rise time can be dynamically adjusted according to the input voltage, so that when the input voltage is low, a shorter first rise time is selected to reduce the temperature rise of the power switch; when the input voltage is high, a longer second rise time is selected to reduce the voltage stress of the secondary rectifier tube. This strategy enables the system to respond flexibly according to the current working conditions, improves the operating efficiency and reliability of the overall power supply, and effectively extends the service life of the equipment. By controlling the time when the driving voltage of the power switch reaches the threshold voltage (i.e., the target rise time), Vspike can be accurately adjusted to further optimize the circuit performance.

[0146] Specifically, the operating characteristic curve of the switching power supply can be obtained by measuring the output voltage, input current, power switch on time and other parameters of the switching power supply under different input voltages. According to these curves, the reasonable target rise time under different input voltages can be determined to ensure the stability of the output voltage. The specific implementation method is as follows.

[0147] The specific implementation method in this embodiment is as follows: First, determine the current operating condition based on multiple operating parameters. For example, the current operating condition can be determined based on the input voltage. Next, determine whether the input voltage is less than the preset input voltage. If it is less than the preset input voltage, the first rise time is selected as the target rise time, that is, the driving voltage rises to the preset conduction value faster on the basis of the initial value to ensure that the power switch is turned on as soon as possible; if it is not less than the preset input voltage, the second rise time is selected as the target rise time, that is, the driving voltage rises to the preset conduction value slower on the basis of the initial value. It should be noted that the first rise time should be less than the second rise time to ensure that the switching power supply can avoid overstress of power devices under different operating conditions.

[0148] In summary, the method provided in this embodiment for determining the target rise time according to the current operating conditions can avoid overstress of power devices under different operating conditions by selecting different rise times, which can not only optimize the performance of the switching power supply, but also improve the working efficiency and safety of the circuit.

[0149] As a preferred embodiment, before selecting the target rise time as the second rise time, it also includes: determining whether the load value connected to the switching power supply is greater than a preset load threshold; if it is greater than the preset load threshold, selecting the target rise time as the second rise time; if it is not greater than the preset load threshold, selecting the target rise time as the third rise time; wherein the first rise time < the second rise time < the third rise time.

[0150] Specifically, it is further considered that when the switching power supply is connected to different loads, different rise times are required to avoid overstress of the power devices. However, the traditional switching power supply design usually only has a fixed rise time and cannot be adjusted for different situations, which can easily lead to damage to the switching tube or unstable operation.

[0151] In view of the above technical problems, this embodiment proposes another rise time adaptive control method for a switching power supply. By obtaining multiple working parameters, different target rise times are determined according to the preset input voltage and load threshold, and the driving voltage of the power switch is controlled to rise from the initial value to the preset turn-on value within the target rise time to turn on the power switch.

[0152] The key in this embodiment is to determine the appropriate target rise time based on the two factors of input voltage and load value to ensure the stable conduction of the switch tube. Different target rise times can be set for different input voltages and load thresholds. When controlling the conduction of the power switch tube, the rising edge of the drive waveform is adjusted according to the requirements of different target rise times to achieve adaptive control, which can make the switching power supply work more stably and reliably under different conditions and achieve a state of relative balance between temperature rise and stress.

[0153] like Figure 7 As shown, Figure 7 A schematic diagram of the driving rise time of the power switch provided by the present invention. In a specific embodiment, the driving waveform TR1 corresponds to the first rise time, the driving waveform TR2 corresponds to the second rise time, and the driving waveform TR3 corresponds to the third rise time. The basis for selecting the waveform is shown in Table 1:

[0154] Table 1

[0155]

[0156] In Table 1, in CCM mode: the current waveform rises rapidly after conduction, and it is necessary to select a driving waveform TR1 with a fast rise time, focusing on suppressing the dynamic resistance effect and alleviating temperature stress. At this time, the secondary rectifier voltage Vspike is large. In order to meet the voltage stress of the secondary rectifier, it is necessary to limit the input voltage upper limit. In this embodiment, the input voltage upper limit is set to 140V. When the input voltage is less than 140V, TR1 is selected as the driving waveform regardless of heavy load or light load.

[0157] In QR mode, if under heavy load (that is, using the valley of the (first few) resonant waveforms to significantly reduce the Drain voltage of the primary power device before conduction), a lower Drain voltage is conducive to reducing the voltage spike Vspike of the secondary rectifier tube, and the voltage stress margin of the secondary rectifier tube is large. A lower Drain voltage is conducive to reducing the dynamic resistance effect of GaN, but at this time, the peak current flowing through the device is large, the surface temperature of the device is high, and the temperature margin is small; therefore, a driving waveform TR2 with a medium rise time is selected to focus on improving temperature stress and taking into account the voltage stress of the secondary rectifier tube. Under light load, after the resonant waveform decays, the valley can no longer significantly reduce the Drain voltage of the primary power device before conduction, and a higher Drain voltage is not conducive to reducing the voltage spike Vspike of the secondary rectifier tube, and the voltage stress margin of the secondary rectifier tube is small; a higher Drain voltage will enhance the dynamic resistance effect of GaN, but at this time, the peak current flowing through the device is reduced, the surface temperature of the device is low, and the temperature margin is large; therefore, a driving waveform TR3 with a slow rise time is selected to focus on suppressing the voltage stress of the secondary rectifier tube. In this embodiment, when the input voltage is greater than 140V and it is heavily loaded (judged by the number of valley conduction, if it is conducted at the 1st to 3rd valley, it is determined to be heavily loaded), TR2 is selected as the driving waveform at this time. If it is lightly loaded (conducted at the 4th to nth valley (n is an integer greater than 4)), TR3 is selected as the driving waveform.

[0158] Among them, when implementing the above rise time adaptive control method, the microprocessor and analog circuit can collect working parameters such as input voltage and load current in real time, calculate the corresponding target rise time and control it, or call the pre-set input voltage-load value-rise time correspondence to determine the target rise time corresponding to the current input voltage and current load value. The specific implementation method may also need to be adjusted according to the specific situation of the circuit design.

[0159] In summary, the method in this embodiment can achieve different rise time adjustments for different input voltages and load conditions, thereby improving the stability and reliability of the switching power supply. At the same time, it can also effectively extend the service life of the power switch tube and improve the working efficiency and service life of the switching power supply.

[0160] like Figure 8 As shown, Figure 8The internal schematic diagram of a primary side controller provided by the present invention, wherein UVLO is used to detect whether the VCC voltage is within a reasonable range, DC bias is used to provide bias current and bias voltage for other modules, OSC is used to generate PWM signals, OCP is used to prevent output overcurrent, Valley is used to detect the magnetic field change of the transformer, the drive module is used to adjust the rise time of the Gate output signal, Line sense is used to detect whether the input voltage is normal, and Load sense is used to monitor whether the load current is overloaded, etc. Specifically, in the drive module, S1 / S2 is used to control the rise time of the Gate output signal.

[0161] As a preferred embodiment, the switching power supply includes a voltage divider circuit, the input end of the voltage divider circuit is connected to the output end of the auxiliary winding of the switching power supply, and when the working parameters include an input voltage, the input voltage of the switching power supply is obtained by determining the input voltage of the switching power supply by collecting the voltage of the voltage divider circuit.

[0162] Specifically, it is not difficult to see from the above embodiments that the input voltage of the switching power supply has a direct impact on its stability and working efficiency, so it is necessary to accurately measure the input voltage and make corresponding adjustments to improve its working efficiency and stability.

[0163] This embodiment selects to use a voltage divider circuit to measure the input voltage of the switching power supply. The output voltage of the voltage divider circuit is proportional to the input voltage, which can improve the measurement accuracy of the input voltage within a certain range. At the same time, in the circuit design, the parameters of the voltage divider circuit should be reasonably selected according to the actual working conditions to meet the input voltage measurement requirements under different working conditions of the switching power supply.

[0164] like Fig.17 As shown, Fig.17 A schematic diagram of an implementation method of a Line Sense module provided by the present invention. As a preferred embodiment, the voltage divider circuit is a resistor voltage divider circuit. The resistor voltage divider circuit can realize voltage drop by connecting one or more resistors, thereby realizing voltage division of the input voltage. In the circuit, selecting a suitable resistor (or winding) can effectively control the voltage drop, thereby improving the measurement accuracy.

[0165] For example, in a voltage divider circuit, if the input voltage is Vin, the output voltage is Vo, and the voltage divider resistors are R1 and R2, then: Vo=Vin×R2 / (R1+R2). According to this formula, we can get the relationship between the output voltage and the input voltage, and then calculate the input voltage. Fig.14Specifically, Vin is detected by resistor voltage division through HV Pin. If Line=L, and Vin>VrefH1×(R1+R2) / R2, the driving waveform is selected as TR1. If Line=H, and Vin<VrefH1×(R1+R2) / R2, the driving waveform is selected as TR2.

[0166] It should be noted that in actual circuit design, suitable resistors can be selected based on factors such as required measurement accuracy, operating current, etc. At the same time, in order to ensure measurement accuracy and stability, components such as filter capacitors need to be added to optimize the circuit.

[0167] In addition to the voltage divider circuit, other circuit methods can also be used to measure the input voltage, such as current sensors, capacitance measurement, etc. When selecting a specific measurement method, factors such as measurement range, accuracy requirements, and power consumption need to be considered.

[0168] In addition, if Fig.18 As shown, Fig.18 This is a schematic diagram of another implementation of the Line Sense module provided by the present invention. As a preferred embodiment, the voltage divider resistor is a winding voltage divider resistor.

[0169] Furthermore, considering that the resistor voltage division measurement method also has the problem of large errors, it is possible to consider using a winding voltage division circuit to collect the input voltage of the switching power supply. This circuit uses the principle of the transformer to reduce the input voltage to a range suitable for measurement through the auxiliary winding, and accurately measures without affecting the operation of the switching power supply. It mainly uses the principle of the proportional transformer, that is, the input voltage (Vin) is proportional to the output voltage (Vo).

[0170] Fig.18 In the process, the winding voltage is divided into two voltages through the DEM Pin, and Vin is detected. Line = L, and , then select the drive waveform as TR1; Line = H, and , then select the driving waveform as TR2; where Np is the number of turns of the primary winding of the transformer, Na is the number of turns of the auxiliary winding of the transformer, and K is the current proportional coefficient. According to this formula, we can achieve precise positioning and transformation of the output voltage by adjusting the ratio of the number of turns of the winding. For example, when the input voltage is high, the output voltage can be reduced by increasing the ratio of the number of turns of the winding, thereby achieving measurement and control of high voltage. In addition, by increasing the number of converters, multi-channel voltage measurement and multi-channel voltage switching can be achieved to achieve measurement of multiple voltages.

[0171] It can be seen that using the winding voltage divider circuit to collect the input voltage of the switching power supply can improve the measurement accuracy and stability, ensure the normal operation of the circuit, and improve the reliability and stability of the entire circuit.

[0172] In summary, the input voltage measurement implemented by the voltage divider circuit (resistance divider or winding) provided in this embodiment can improve its accuracy and stability, thereby improving the working efficiency and stability of the switching power supply. At the same time, this method has a certain universality and can also be applied in other circuit designs.

[0173] As a preferred embodiment, when the working parameter includes a load value connected to the switching power supply, the load value connected to the switching power supply is obtained by obtaining the output power of the switching power supply and determining the load value of the switching power supply according to the output power.

[0174] In order to solve the problem of accurately measuring the load value, in this embodiment, the load value can be determined by calculating the output power of the switching power supply. The specific implementation method is to use a power meter to measure the power, and then obtain the corresponding load value through simple calculation.

[0175] Specifically, the output power of the switching power supply can be calculated by multiplying the voltage and current. The power meter collects and processes the voltage and current signals, and then calculates the power value. In the existing switching power supply system, a power measurement module can be added, and the power meter can be used to measure the power value, and the load value can be calculated according to the above calculation formula. Specifically, the power meter can directly calculate the power value by collecting voltage and current signals. During measurement, the corresponding signal value can be collected according to the output voltage and current of the switching power supply, and then the corresponding load value can be obtained by power calculation. Assuming that the output voltage of the switching power supply is U and the output current is I, the output power is P=U×I.

[0176] In addition to the above implementation methods, digital signal processing technology can also be used to filter, sample, quantize and process the collected voltage and current signals to improve measurement accuracy.

[0177] In summary, in this embodiment, by using the power measurement technology, the load value connected to the switching power supply can be accurately obtained to ensure system stability and work efficiency. This is particularly important for some system applications with high load requirements.

[0178] As a preferred embodiment, obtaining the output power of the switching power supply includes: obtaining a feedback voltage output by a feedback pin of the switching power supply, and determining the output power of the switching power supply according to the feedback voltage.

[0179] A common circuit for obtaining feedback voltage and output power is to use a differential amplifier. The principle is to differentiate the voltage of the feedback pin from the reference voltage, amplify and filter the differential signal through the amplifier, and obtain the magnitude of the feedback voltage. Then, the proportional relationship between the feedback voltage and the reference voltage is used to calculate the output power value. Fig.19 , Fig.19 Schematic diagram of an implementation method of Load Sense provided by the present invention. In this embodiment, the output power of the system is characterized by the voltage of the FB Pin. When Load = H and VFB > VrefH3, it is determined as heavy load; when Load = L, if VFB < VrefL3, it is determined as light load.

[0180] As a preferred embodiment, obtaining the output power of the switching power supply includes: determining the number of valley points of the resonant waveform corresponding to the conduction stage of the primary power switch, and determining the output power according to the number of valley points.

[0181] In this embodiment, the output power of the switching power supply is obtained by analyzing the resonant waveform generated during the conduction stage of the primary power switch Qp. Specifically, the number of valley points of the resonant waveform is an important characteristic parameter that can reflect the dynamic response of the power supply under specific working conditions. When Qp conducts, the changes in current and voltage cause resonance to occur, generating a periodic waveform. By observing the number of valley points in these waveforms, the power change in each period can be judged. Generally speaking, an increase in the number of valley points means an increase in the output power, because this indicates that the power supply has completed more energy conversion and transmission within a certain period of time. On the contrary, a decrease in the number of valley points may indicate a decrease in the output power. Therefore, by real-time monitoring and counting the valley points of the resonant waveform, combined with the parameters and working conditions of the system, the output power of the switching power supply can be calculated.

[0182] Among them, in order to measure the number of valley points of the resonant waveform, the signal output by the resonant circuit for measuring the resonant waveform can be input into the microprocessor. The microprocessor will sample the input signal and perform digital signal processing to accurately measure the number of valley points of the resonant waveform and calculate the output power according to the number of valley points. As Fig. 20 , Fig. 20 Schematic diagram of another implementation method of Load Sense provided by the present invention. In one embodiment, if Load = H and the number of valley points N > 4, it is determined as heavy load; if Load = L and the number of valley points N ≤ 4, it is determined as light load.

[0183] This method of determining the output power can greatly reduce costs and time.

[0184] As a preferred embodiment, obtaining the output power of the switching power supply includes: obtaining the output current on the primary side of the switching power supply, and determining the output power according to the output current.

[0185] This embodiment aims to provide another implementation method for obtaining the output power of a switching power supply. To obtain the output power of a switching power supply, the method of measuring the output current of the primary side is generally adopted, because the output current of the primary side directly reflects the output power of the power supply. This method of obtaining the output power of a switching power supply essentially utilizes the relationship between current and voltage. By measuring the voltage and resistance value, the current magnitude is obtained, and then the power can be obtained by multiplying the voltage. When selecting a resistor, it is necessary to ensure that the resistor can withstand the current intensity without being damaged based on the rated output current of the power supply. In addition, in actual measurement, it is also necessary to pay attention to the temperature rise of the resistor to avoid erroneous measurement results due to excessive temperature rise.

[0186] like Fig. 20 In one embodiment, the output current is calculated using the CS Pin voltage and Tsw,Tons , represents the system output power. Load=H, if Io>IrefH, it is heavy load; Load=L, if Io<IrefL, it is light load.

[0187] As a preferred embodiment, the switching power supply includes a driving circuit, the driving circuit includes a driving capacitor, a first driving switch and a second driving switch, the first end of the driving capacitor is grounded, the second end of the driving capacitor is connected to the control end of the first driving switch, the first end of the first driving switch is connected to the power supply, the second end of the first driving switch is respectively connected to the control end of the power switch and the first end of the second driving switch, and the second end of the second driving switch is grounded; controlling the driving voltage of the power switch to rise from an initial value to a preset conduction value within a target rise time includes: charging and discharging the driving capacitor to adjust the voltage of the driving capacitor so that the voltage of the driving capacitor rises from an initial value to a first voltage value within the target rise time to turn on the first driving switch; wherein, when the voltage of the driving capacitor reaches the first voltage value, the second driving switch is turned off, the voltage of the control end of the power switch reaches the preset conduction value, and the power switch is turned on. The driving capacitor can refer to Figure 9-12 Cp in the figure is the sum of the parasitic capacitance between the control terminal of N1 and the ground, not the physical capacitance.

[0188] In this embodiment, the switching power supply controls the conduction process of the power switch through the driving circuit, and the core lies in the charging and discharging process of the driving capacitor. First, the initial voltage of the driving capacitor is low, and by charging it, the voltage of the capacitor is gradually increased to achieve a preset target rise time. Within the target rise time, the voltage of the driving capacitor rises smoothly to ensure that when it reaches the first voltage value, it can stably control the conduction of the first driving switch. At this time, the conduction of the first driving switch enables the control end of the power switch to obtain sufficient driving voltage, thereby achieving conduction. At the same time, the second driving switch remains in the cut-off state during the rising process of the driving capacitor voltage. This state ensures that the power switch is activated at the right time and avoids unnecessary interference or false triggering.

[0189] By precisely controlling the voltage change of the driving capacitor, the system can effectively manage the on-time of the power switch, improve the overall efficiency and stability of the switching power supply, reduce the temperature rise of the power switch, and optimize the output performance of the power supply.

[0190] To solve the above technical problems, Figure 9-12 As shown, the present invention provides a switching power supply adaptive driving device, comprising:

[0191] A detection circuit, used to obtain multiple operating parameters of the switching power supply under current working conditions;

[0192] An adjustment circuit is used to select a target rise time required for turning on a power switch corresponding to a current working condition according to a plurality of working parameters;

[0193] The driving circuit is used to control the driving voltage of the power switch to rise from an initial value to a preset turn-on value within a target rise time, so as to turn on the power switch.

[0194] The switching power supply adaptive driving device in the present invention optimizes the conduction process of the power switch through the coordinated work of three main circuits to cope with the performance requirements under different working conditions. First, the detection circuit is responsible for obtaining multiple working parameters of the switching power supply in real time, such as input voltage, load conditions and other operating status information. These parameters provide the necessary data basis for the adjustment circuit, enabling it to analyze the characteristics of the current working conditions. Then, the adjustment circuit selects a suitable target rise time according to the obtained working parameters to adapt to the dynamic response required for the power switch to be turned on under the current working conditions. The setting of the target rise time is intended to balance the conduction efficiency and safety of the power switch, thereby avoiding excessive temperature rise or excessive voltage stress. Finally, the drive circuit is responsible for smoothly increasing the driving voltage of the power switch from the initial value to the preset conduction value within the set target rise time, ensuring that the power switch can be stably turned on at the best time. Through this adaptive driving mechanism, the entire switching power supply system can flexibly adjust the operating parameters according to the real-time working state, improve the stability and efficiency of the system, and ensure that the power supply can work reliably under various working conditions.

[0195] As a preferred embodiment, the driving circuit includes a driving capacitor, a first driving switch and a second driving switch, the first end of the driving capacitor is grounded, the second end of the driving capacitor is connected to the control end of the first driving switch, the first end of the first driving switch is connected to the power supply, the second end of the first driving switch is respectively connected to the control end of the power switch and the first end of the second driving switch, the second end of the second driving switch is grounded, and the conduction state of the first driving switch is opposite to the conduction state of the second driving switch;

[0196] A driving circuit, specifically used to control the voltage of the driving capacitor to rise from an initial value to a first voltage value within a target rise time;

[0197] When the voltage of the driving capacitor reaches the first voltage value, the first driving switch is turned on, the second driving switch is turned off, the voltage of the control end of the power switch reaches the preset turn-on value, and the power switch is turned on. Figure 9-12 Cp in the figure is the sum of the parasitic capacitance between the control terminal of N1 and the ground, not the physical capacitance.

[0198] In this embodiment, the design of the drive circuit accurately controls the conduction process of the power switch through the cooperation of the drive capacitor and its control switch. First, the drive capacitor has a lower voltage in the initial state. By charging it, the voltage of the drive capacitor gradually rises within the set target rise time. When the voltage rises to the first voltage value, the state change of the drive capacitor triggers the first drive switch to turn on, while keeping the second drive switch in the off state. This control strategy ensures that the power switch will be activated only when the voltage of the drive capacitor reaches the preset value, thereby achieving stable conduction. The conduction of the first drive switch provides the necessary driving voltage for the power switch, ensuring that the power switch can be smoothly turned on at the right time, thereby controlling the output of the power supply. Through this precise voltage control mechanism, the drive circuit can effectively manage the conduction time of the power switch, improve the overall performance and efficiency of the switching power supply, and ensure the reliability and stability of the power supply under various working conditions.

[0199] As a preferred embodiment, the driving circuit also includes: a charging regulation circuit, one end of which is connected to the second end of the driving capacitor, and the other end of which is connected to the adjustment circuit; the charging regulation circuit is used to adjust its own working state according to the target rise time selected by the adjustment circuit to provide a target charging current for the driving capacitor so that the voltage of the driving capacitor reaches a first voltage value within the target rise time; wherein the target charging current is negatively correlated with the target rise time.

[0200] In this embodiment, the design of the charging regulation circuit is closely linked to the charging process of the driving capacitor to achieve precise control of the target rise time. Specifically, the charging regulation circuit dynamically adjusts its working state according to the target rise time selected by the adjustment circuit to provide an appropriate target charging current to the driving capacitor. Since the target charging current is negatively correlated with the target rise time, this means that when the target rise time is shorter, the charging regulation circuit will increase the charging current, thereby speeding up the voltage rise rate of the driving capacitor; conversely, when the target rise time is longer, the charging current will decrease to reduce the charging rate. This design allows the system to flexibly adjust the charging process under different working conditions to ensure that the voltage of the driving capacitor accurately reaches the first voltage value within the set target rise time.

[0201] Through this mechanism, the charging regulation circuit can not only optimize the turn-on timing of the power switch, but also improve the overall efficiency and response speed of the switching power supply, ensuring its stability and reliability under different working conditions.

[0202] As a preferred embodiment, the charging regulation circuit includes: a switching circuit, N constant current sources and M auxiliary capacitors, N≥1, M≥0, N+M≥2, and N and M are both integers; the first end of the switching circuit is connected to all the constant current sources, the second end of the switching circuit is connected to all the auxiliary capacitors, and the third end of the switching circuit is connected to the second end of the driving capacitor; the constant current source is used to provide a constant current; the switching circuit is used to adjust its own path state according to the target rise time to select the first target number of constant current sources and the second target number of auxiliary capacitors to access the circuit, so that the first target number of constant current sources charges the driving capacitor and the second target number of auxiliary capacitors; the first target number is at least 1, the second target number is at least 0, the first target number is negatively correlated with the target rise time, and the second target number is positively correlated with the target rise time.

[0203] In this embodiment, the design of the charging regulation circuit realizes precise management of the charging process of the driving capacitor by flexibly controlling the number of constant current sources and auxiliary capacitors. Specifically, the charging regulation circuit dynamically adjusts the number of constant current sources and auxiliary capacitors connected to the circuit according to the set target rise time through the switching circuit. As the target rise time changes, when the target rise time is short, the switching circuit can choose to connect more constant current sources to provide a larger charging current, and / or reduce the number of auxiliary capacitors connected, thereby speeding up the charging speed of the driving capacitor and making it reach the first voltage value faster. This negative correlation ensures that the driving capacitor can be charged to the expected voltage in a shorter time when a fast response is required. On the other hand, when the target rise time is long, the switching circuit can reduce the number of constant current sources connected, and / or increase the number of auxiliary capacitors connected. The auxiliary capacitor shares the charging current of the driving capacitor during the charging process, thereby achieving a slower voltage rise rate.

[0204] Through flexible configuration, the charge regulation circuit can optimize the charging characteristics of the drive capacitor under various working conditions, thereby improving the response speed and overall performance of the switching power supply.

[0205] As a preferred embodiment, when N>1 and M=0, the switch circuit includes: a main switch and a first switch circuit; one end of the first switch circuit is connected to the output ends of n constant current sources, the other end of the first switch circuit is respectively connected to the output ends of other constant current sources except the n constant current sources and one end of the main switch, the other end of the main switch is respectively connected to the second end of the driving capacitor and the control end of the first driving switch, and the control end of the first switch circuit is connected to the adjustment circuit; N>n≥1, n is an integer; the main switch is used to be turned on when charging the driving capacitor; the first switch circuit is used to adjust its own path state to select a third target number of constant current sources to access the circuit, the first target number-the third target number=Nn.

[0206] In this embodiment, when N is greater than 1 and M is 0, the design of the charging regulation circuit focuses on optimizing the charging process of the driving capacitor by flexibly adjusting the number of constant current sources. Specifically, the switch circuit includes a main switch and a first switch circuit, and the main switch is responsible for conducting during charging to ensure that the driving capacitor can receive current. The first switch circuit dynamically selects the number of constant current sources connected to the circuit according to the control signal of the adjustment circuit. Here, the n constant current sources are constant current sources that can be flexibly adjusted, and the other constant current sources except the n constant current sources are pre-fixed constant current sources, which are specifically provided with a stable charging current for the driving capacitor and are not affected by the adjustment. By adjusting the access state of the first switch circuit, the system can select a second target number of constant current sources from the n constant current sources for access. Such a design makes it possible that at any given target rise time, the first target number of constant current sources always provide charging current for the driving capacitor, and this first target number minus the third target number is the number of Nn constant current sources that cannot be adjusted.

[0207] like Fig. 9 As shown, the number of constant current sources N is 3, n is 2, P1 is the main switch, P2 and P3 form the first switch circuit, the charging current is adjusted according to the target rise time, and the rising edge waveform is set, wherein the output Gate is used to drive the power switch, wherein the first turning point of the Gate waveform (refer to Fig.13 The second turning point (refer to Fig.13 At t2, the voltage of VH determines the switching of S1+Gate to Ib3 and S2 to Ib2.

[0208] S1=H, enable Ib3 in the middle of the rise; S2=H, enable Ib2, corresponding to the shortest target rise time and the fastest Gate rise.

[0209] S1=L, disable Ib3 in the middle of the rise; S2=H, enable Ib2, corresponding to the target rise time being medium and the Gate rise being medium.

[0210] S1=L, disable Ib3 in the middle of the rise; S2=L, disable Ib2, corresponding to the slowest target rise time and the slowest Gate rise.

[0211] In this way, the system can flexibly adapt to different operating conditions, quickly respond to changing target rise times, and drive the capacitor to reach the required voltage within the set time, thereby improving the performance and reliability of the switching power supply.

[0212] As a preferred embodiment, when N=1 and M>0, the switching circuit includes: a main switch and a second switching circuit; one end of the main switch is connected to all constant current sources, one end of the second switching circuit is connected to the first ends of m auxiliary capacitors, the other end of the second switching circuit is respectively connected to the first ends of other auxiliary capacitors except the m auxiliary capacitors and the other end of the main switch, the second end of the driving capacitor and the control end of the first driving switch, the second ends of all auxiliary capacitors are grounded, the second end of the second switching circuit is connected to the adjustment circuit, M≥m>0, m is an integer; the main switch is used to turn on when charging the driving capacitor; the second switching circuit is used to adjust its own path state to select a fourth target number of auxiliary capacitors to access the circuit, the second target number-the fourth target number=Mm.

[0213] In this embodiment, when N is 1 and M is greater than 0, the design of the charging regulation circuit optimizes the charging process of the driving capacitor by adjusting the number of auxiliary capacitors. At this time, the main switch is responsible for turning on during the charging process to ensure that the driving capacitor can receive a fixed charging current from the constant current source. At the same time, the function of the second switch circuit is to flexibly adjust the number of auxiliary capacitors connected to the circuit so as to share the charging current of the driving capacitor. In this embodiment, there are m adjustable auxiliary capacitors and Mm fixed auxiliary capacitors, the latter (the minimum number can be 0) have been pre-set and used to stably share the charging current. The second switch circuit dynamically selects the number of auxiliary capacitors connected according to the target rise time to ensure that the distribution of the charging current is effectively managed within a given time, and ensures that the driving capacitor obtains an appropriate charging current. Among them, the fourth target number + the number of other auxiliary capacitors other than the m auxiliary capacitors = the second target number. In this case, the number of adjusted m auxiliary capacitors can directly affect the charging speed of the driving capacitor and optimize its voltage rise process.

[0214] like Fig.10 As shown, the number of constant current sources is 1, the number of auxiliary capacitors M is 2 (respectively C1 and C2), P1 is the main switch, N4-N7 form the second switch circuit, the number of connected auxiliary capacitors is adjusted according to the target rise time, and the rising edge waveform is set, wherein the output Gate is used to drive the power switch, wherein the first turning point of the Gate waveform (refer to Fig.13 The second turning point (refer to Fig.13 (At time t2) due to N4 / N6 turnoff, S1 switches to C1, S2 switches to C2, C1, C2 need to be controlled by a bidirectional isolating switch. The bidirectional isolating switch can be composed of P and N in series, or N and N in series.

[0215] S1=H, disable C1; S2=H, disable C2, the corresponding target rise time is the shortest and the Gate rise is the fastest.

[0216] S1=L, enable C1; S2=H, disable C2, corresponding to medium target rise time and medium Gate rise time.

[0217] S1=L, enable C1; S2=L, enable C2, corresponding to the slowest target rise time and the slowest Gate rise time.

[0218] This flexible design enables the system to adapt to different operating conditions, ensuring that the drive capacitor can be charged stably and efficiently while meeting specific rise time requirements, thereby improving the performance and reliability of the switching power supply.

[0219] As a preferred embodiment, when N>1 and M>0, the switch circuit includes: a main switch, a first switch circuit and a second switch circuit; one end of the first switch circuit is connected to the output ends of the n constant current sources, the other end of the first switch circuit is respectively connected to the output ends of other constant current sources except the n constant current sources and one end of the main switch, the other end of the main switch is respectively connected to the first end of the second switch circuit, the first end of other auxiliary capacitors except the m auxiliary capacitors, the second end of the driving capacitor and the control end of the first driving switch, the other end of the second switch circuit is connected to the m auxiliary capacitors , the second ends of all auxiliary capacitors are grounded, and the control ends of the first switch circuit and the second switch circuit are connected to the adjustment circuit; N>n≥1, M≥m>0, m and n are integers; the main switch is used to be turned on when charging the driving capacitor; the first switch circuit is used to adjust its own path state to select a third target number of constant current sources to access the circuit, the first target number - the third target number = Nn; the second switch circuit is used to adjust its own path state to select a fourth target number of auxiliary capacitors to access the circuit, the second target number - the fourth target number = Mm.

[0220] In the present embodiment, when N and M are both greater than 0 and N is greater than 1, the design of the charging regulation circuit combines the flexible adjustment of the constant current source and the number of auxiliary capacitors to optimize the charging process of the driving capacitor. First, the main switch is turned on during charging to provide the necessary power supply for the driving capacitor. Then, the first switching circuit is responsible for adjusting the number of constant current sources connected to the circuit so as to dynamically select a suitable constant current source according to the target rise time. In this process, the output ends of the n constant current sources are connected to the first switching circuit, and through the adjustment of the switch, a suitable third target number of constant current sources are selected to access the circuit. Among them, the n constant current sources can be flexibly adjusted, and other constant current sources except the n constant current sources are used to stably provide the charging current of the driving capacitor. This enables the system to adapt to changes according to demand and flexibly configure the charging current during the charging process.

[0221] At the same time, the second switch circuit controls the access of the auxiliary capacitors, and through the adjustment of its control terminal, selects the fourth target number of auxiliary capacitors to be connected according to the target rise time. At this time, the m auxiliary capacitors can be flexibly adjusted, and the other auxiliary capacitors except the m auxiliary capacitors are used to stably share the charging current of the driving capacitor.

[0222] like Fig.11 and Fig.12 As shown, the number of constant current sources is 2, the number of auxiliary capacitors M is 1 (the auxiliary capacitor is C1, P1 is the main switch, P2 is the first switch circuit, P3 and N4, or N4 and N5 form the second switch circuit, and the number of constant current sources and the number of auxiliary capacitors connected are adjusted according to the target rise time, and the rising edge waveform is set, wherein the output Gate is used to drive the power switch, wherein the first turning point of the Gate waveform (refer to Fig.13 The second turning point (refer to Fig.13 At time t2, VC1 rises, N4 turns off, S1 switches C1, and C1 needs to be controlled by a bidirectional isolating switch. The bidirectional isolating switch can be composed of P3 and N4 in series, or N4 and N5 in series. S2 switches the constant current source.

[0223] S1=H, disable C1; S2=H, IB=Ib1+Ib2, the corresponding target rise time is the shortest and the Gate rise is the fastest.

[0224] S1=L, enable C1; S2=H, IB=Ib1+Ib2, corresponding to medium target rise time and medium Gate rise time.

[0225] S1=L, enable C1; S2=L, IB=Ib1, corresponding to the slowest target rise time, the slowest Gate rise time.

[0226] This design allows the system to flexibly adjust the number of constant current sources and auxiliary capacitors under different working conditions to ensure that the drive capacitor is effectively charged within the predetermined target rise time, thereby improving the overall performance and reliability of the switching power supply. By combining the adjustment of the constant current source and auxiliary capacitor, the system can more accurately meet the needs of dynamic changes and optimize the responsiveness of the power supply.

[0227] As a preferred embodiment, the first switch circuit includes: n controllable switches, corresponding to n constant current sources one by one, each controllable switch is arranged between the output end of the constant current source corresponding to itself and one end of the main switch, and the control end of each controllable switch is connected to the adjustment circuit; the drive circuit also includes: a control circuit, connected to at least one controllable switch among the n controllable switches, the control circuit includes a first comparator, a second comparator, a NAND gate and an OR gate; wherein, the first comparison voltage value is input to the positive input end of the first comparator, the preset conduction value is input to the negative input end of the first comparator and the positive input end of the second comparator, the second comparison voltage value is input to the negative input end of the second comparator, the output end of the first comparator and the output end of the second comparator are respectively connected to the two input ends of the NAND gate, the output end of the NAND gate is connected to the first input end of the OR gate, the second input end of the OR gate is connected to the adjustment circuit, and the output end of the OR gate is connected to the control end of at least one controllable switch; the first comparison voltage value is greater than the second comparison voltage value.

[0228] In this embodiment, the first switch circuit corresponds to n constant current sources through n controllable switches, aiming to flexibly adjust the access of the constant current source according to actual needs to optimize the charging process of the driving capacitor. The control end of each controllable switch is connected to the control circuit, and the core function of the control circuit is to monitor and adjust the charging state in real time. Specifically, the control circuit is composed of a first comparator, a second comparator, a NAND gate and an OR gate. The first comparator is responsible for comparing the first comparison voltage value with the preset conduction value to evaluate whether the current charging state reaches the required level; if the first comparison voltage value is higher than the preset conduction value, the first comparator will output a high level signal. At the same time, the function of the second comparator is to monitor the second comparison voltage value and compare it with the preset conduction value to ensure that the voltage during the charging process does not exceed the safe range. When the second comparison voltage value is lower than the preset conduction value, the second comparator will also output a corresponding signal. Subsequently, the output results of the first comparator and the second comparator are jointly input to the NAND gate, and a comprehensive judgment of the charging state is obtained through logical operation. This judgment result is further transmitted to the OR gate, and the output of the OR gate will affect the control end of at least one controllable switch, thereby determining whether to turn on or off a specific constant current source.

[0229] Through such a monitoring and control mechanism, the number of connected constant current sources can be dynamically adjusted to ensure that the driving capacitor always remains within a safe and effective working range during the charging process, thereby improving the reliability and efficiency of the switching power supply.

[0230] As a preferred embodiment, the second switch circuit includes: m sub-switch circuits, m third clamping circuits, and m resistors, and the m sub-switch circuits, m third clamping circuits, m resistors, and m auxiliary capacitors correspond to each other one by one; the first end of each sub-switch circuit is respectively connected to the first end of the auxiliary capacitor corresponding to itself, the first end of the third clamping circuit corresponding to itself, and the first end of the resistor corresponding to itself, the second end of each auxiliary capacitor and the second end of each third clamping circuit are grounded, the second end of each resistor inputs a preset clamping voltage, and the control end of each sub-switch circuit is connected to the adjustment circuit.

[0231] In this embodiment, the design of the second switch circuit is mainly to flexibly adjust and accurately control the m auxiliary capacitors to optimize the working performance of the switching power supply. Each sub-switch circuit corresponds to its corresponding auxiliary capacitor, the third clamping circuit and the resistor one by one to form an independent control unit. When the sub-switch circuit is activated, it will allow the auxiliary capacitor to be connected to the circuit, thereby participating in the charging process. At the same time, the role of the third clamping circuit is to ensure that the voltage of the auxiliary capacitor does not exceed the preset clamping voltage during the charging or discharging process, thereby preventing potential damage caused by excessive voltage. The role of each resistor is to provide a reference point, and by inputting a preset clamping voltage, the accuracy of voltage control is further improved. The adjustment circuit dynamically selects whether to connect a specific auxiliary capacitor by controlling the state of the sub-switch circuit, thereby flexibly adjusting the charging of the capacitor according to the actual needs of the system.

[0232] Through such a design, it is possible to effectively cope with different working environments while maintaining power supply stability, improving overall efficiency and reliability. The flexibility and accuracy of this solution enable the switching power supply to better adapt to changing load conditions and achieve efficient power management.

[0233] As a preferred embodiment, the driving circuit further includes: a NOT gate, a third driving switch, a first clamping circuit, a second clamping circuit and a PWM output module; the first output end of the PWM output module is respectively connected to the input end of the NOT gate and the control end of the third driving switch, the output end of the NOT gate is connected to the control end of the main switch, the first end of the third driving switch is respectively connected to the first end of the first clamping circuit, the first end of the second clamping circuit, the second end of the driving capacitor and the control end of the first driving switch, the second end of the third driving switch, the second end of the first clamping circuit and the second end of the second clamping circuit are all grounded, and the second output end of the PWM output module is connected to the control end of the second driving switch; the signal levels output by the two output ends of the PWM output module are opposite.

[0234] In this embodiment, the design of the drive circuit is mainly to achieve precise control of the switching power supply through the cooperation of the PWM output module, the NOT gate and the third drive switch. The pulse width modulation signal generated by the PWM output module generates an output opposite to it through the NOT gate. This symmetrical signal output mechanism makes it possible to effectively control the on and off of the main switch under different working conditions. Specifically, the PWM signal is used to adjust the control end of the third drive switch, thereby adjusting the on state of the switch and affecting the charging of the drive capacitor. The functions of the first clamping circuit and the second clamping circuit are to ensure that the drive capacitor works within the set range, and to avoid excessively high or low voltages affecting the stability of the system by limiting the voltage. When the signal level of the PWM output module changes, the change of the NOT gate output signal will affect the control of the main switch, thereby realizing dynamic adjustment of the entire power supply state. The flexibility of this design enables the drive circuit to quickly respond to load changes, optimize power supply efficiency, and enhance the reliability and stability of the system. Through precise voltage and state control, this embodiment effectively improves the adaptability and performance of the switching power supply under various working conditions.

[0235] In the implementation provided in this embodiment, the workflow of each working device is as follows:

[0236] Timing diagram Fig.13 As shown, Fig.13 This is a timing diagram of each device in the driving module provided by the present invention.

[0237] When S1=H, N4 is turned off, and the Gate rise time is TR1. The timing waveform is shown in Fig.10. At t0, the output lower tube N2 is turned off; at t1, P1 is turned on, the Cp capacitor is charged, the Gate rise slope dV / dt=IB / Cp, IB=Ib1 or Ib1+Ib2, and the output upper tube N1 is turned on; at t2, the Gate voltage reaches the clamped high level; at t3, the output upper tube N1 is turned off; at t4, the output lower tube N2 is turned on.

[0238] When S1=L, N4, P3, and P4 are controlled by H; when S2=L, P2 is cut off; the Gate rise time is TR2, and the timing waveform is shown in Fig.13At t0, the output lower tube N2 is cut off, P4 is cut off, N4 and P3 are cut off; at t1, the C1 capacitor charges the Cp capacitor, and the output upper tube N1 is turned on; at t1~t2, P1 is turned on, the Cp capacitor is charged, and the Gate rising slope dV / dt=IB / (Cp+C1), IB=Ib1; at t2, due to the rise of VC1 voltage, N4 is cut off, the Cp capacitor is charged, and the Gate rising slope dV / dt=IB / Cp, IB=Ib1; at t3, the Gate voltage reaches the clamped high level; at t4, the output upper tube N1 is cut off, N4 and P3 are cut off, P4 is turned on, and Ib3 charges the C1 capacitor; at t5, the output lower tube N2 is turned on.

[0239] When S1=L, N4, P3, and P4 are controlled by H; when S2=H, P2 is turned on, and the Gate rise time is TR3. For the timing waveform, see Fig.13 At t0, the output lower tube N2 is turned off; at t1, P4 is turned off, N4 and P3 are turned on, the C1 capacitor charges the Cp capacitor, and the output upper tube N1 is turned on; at t1~t2, P1 is turned on, the Cp capacitor is charged, and the Gate rising slope dV / dt=IB / (Cp+C1), IB=Ib1+Ib2; at t2, due to the rise of VC1 voltage, N4 is turned off, the Cp capacitor is charged, and the Gate rising slope dV / dt=IB / Cp, IB=Ib1+Ib2; at t3, the Gate voltage reaches the clamped high level; at t4, the output upper tube N1 is turned off, N4 and P3 are turned off, P4 is turned on, and Ib3 charges the C1 capacitor; at t5, the output lower tube N2 is turned on.

[0240] Where Cp is the total parasitic capacitance of the H_G node, C1 is the auxiliary capacitance (C1>Cp), and Ib1 / Ib2 / Ib3 are constant current sources. Non-overlap circuits are used to avoid N1 and N2 being common, such as Fig.14 , Fig.14 The circuit and signal timing diagram of the Non-Overlap module provided by the present invention; the LevelShift circuit is used for level conversion to control the gates of P1 and P2, such as Fig.15 , Fig.15 The circuit diagram of the Level-Shift module provided by the present invention; Clamp1 is a GATE output high level clamp circuit, Clamp2 is a C1 high level clamp circuit, and Clamp3 is an N1 gate voltage clamp circuit. Fig.16 , Fig.16 A circuit diagram of the Clamp module provided by the present invention.

[0241] In this embodiment, the driving circuit is implemented by hardware, which can achieve fast response, stable and reliable control, and improve the efficiency and stability of the driving circuit.

[0242] To solve the above technical problems, the present invention provides a switching power supply, including the above-mentioned switching power supply adaptive driving device. For the specific introduction of the switching power supply, please refer to the above-mentioned embodiment, and the present invention will not be repeated here.

[0243] It should also be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0244] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A switching power supply adaptive driving method, characterized in that: include: Acquire multiple operating parameters of the switching power supply under current working conditions; According to the plurality of operating parameters, selecting a target rise time required for turning on the power switch corresponding to the current operating condition; The driving voltage of the power switch is controlled to increase from an initial value to a preset turn-on value within the target rise time, so as to turn on the power switch.

2. The switching power supply adaptive driving method according to claim 1, characterized in that: The power switch is a gallium nitride power switch.

3. The switching power supply adaptive driving method according to claim 1, characterized in that: The preset conduction value is a threshold voltage of the power switch.

4. The switching power supply adaptive driving method according to claim 1, characterized in that: The operating parameters at least include an input voltage of the switching power supply and / or a load value connected to the switching power supply.

5. The switching power supply adaptive driving method according to claim 4, characterized in that: Determining a target rise time corresponding to the current working condition according to the plurality of working parameters includes: Determining whether the input voltage of the switching power supply is less than a preset input voltage; If it is less than the preset input voltage, selecting the target rise time as the first rise time; If it is not less than the preset input voltage, selecting the target rise time as the second rise time; The first rise time is less than the second rise time.

6. The switching power supply adaptive driving method according to claim 5, characterized in that: Before selecting the target rise time as the second rise time, the method further includes: Determining whether a load value connected to the switch power supply is greater than a preset load threshold; If it is greater than the preset load threshold, selecting the target rise time as the second rise time; If it is not greater than the preset load threshold, selecting the target rise time as the third rise time; The first rise time is less than the second rise time and less than the third rise time.

7. The switching power supply adaptive driving method according to claim 4, characterized in that: The switching power supply includes a voltage divider circuit, the input end of the voltage divider circuit is connected to the output end of the auxiliary winding of the switching power supply, and when the operating parameter includes an input voltage, the input voltage of the switching power supply is obtained in the following manner: The input voltage of the switching power supply is determined by collecting the voltage of the voltage divider circuit.

8. The switching power supply adaptive driving method according to claim 7, characterized in that: The voltage divider circuit is a resistor voltage divider circuit or a winding voltage divider circuit.

9. The switching power supply adaptive driving method according to claim 4, characterized in that: When the operating parameter includes a load value connected to the switching power supply, the load value connected to the switching power supply is obtained in the following manner: The output power of the switching power supply is acquired, and a load value of the switching power supply is determined according to the output power.

10. The switching power supply adaptive driving method according to claim 9, characterized in that: Obtaining the output power of the switching power supply, comprising: A feedback voltage outputted by a feedback pin of the switching power supply is obtained, and the output power of the switching power supply is determined according to the feedback voltage.

11. The switching power supply adaptive driving method according to claim 9, characterized in that: Obtaining the output power of the switching power supply, comprising: The valley number of the resonant waveform corresponding to the conduction phase of the primary power switch is determined, and the output power is determined according to the valley number.

12. The switching power supply adaptive driving method according to claim 9, characterized in that: Obtaining the output power of the switching power supply, comprising: The output current of the primary side of the switching power supply is obtained, and the output power is determined according to the output current.

13. The adaptive driving method of a switching power supply according to any one of claims 1 to 12, characterized in that: The switching power supply comprises a driving circuit, wherein the driving circuit comprises a driving capacitor, a first driving switch and a second driving switch, wherein a first end of the driving capacitor is grounded, a second end of the driving capacitor is connected to a control end of the first driving switch, a first end of the first driving switch is connected to a power supply, a second end of the first driving switch is respectively connected to a control end of the power switch and a first end of the second driving switch, and a second end of the second driving switch is grounded; Controlling the driving voltage of the power switch to rise from an initial value to a preset conduction value within the target rise time includes: By charging and discharging the driving capacitor, the voltage of the driving capacitor is adjusted so that the voltage of the driving capacitor rises from the initial value to the first voltage value within the target rising time, so that the first driving switch is turned on; When the voltage of the driving capacitor reaches the first voltage value, the second driving switch is turned off, and when the voltage of the control terminal of the power switch reaches the preset conduction value, the power switch is turned on.

14. A switching power supply adaptive driving device, characterized in that: include: A detection circuit, used to obtain multiple operating parameters of the switching power supply under current working conditions; An adjustment circuit, used for selecting a target rise time required for turning on the power switch corresponding to the current working condition according to the plurality of working parameters; The driving circuit is used to control the driving voltage of the power switch to rise from an initial value to a preset turn-on value within the target rise time, so as to turn on the power switch.

15. The switching power supply adaptive driving device according to claim 14, characterized in that: The driving circuit comprises a driving capacitor, a first driving switch and a second driving switch, wherein a first end of the driving capacitor is grounded, a second end of the driving capacitor is connected to a control end of the first driving switch, a first end of the first driving switch is connected to a power supply, a second end of the first driving switch is respectively connected to a control end of the power switch and a first end of the second driving switch, a second end of the second driving switch is grounded, and a conduction state of the first driving switch is opposite to a conduction state of the second driving switch; The driving circuit is specifically used to control the voltage of the driving capacitor to rise from the initial value to the first voltage value within the target rising time; When the voltage of the driving capacitor reaches the first voltage value, the first driving switch is turned on, the second driving switch is turned off, and the voltage of the control terminal of the power switch reaches the preset turn-on value, and the power switch is turned on.

16. The switching power supply adaptive driving device according to claim 15, characterized in that: The driving circuit further includes: A charging regulation circuit, one end of which is connected to the second end of the driving capacitor, and the other end of which is connected to the adjustment circuit; The charging regulation circuit is used to adjust its own working state according to the target rise time selected by the adjustment circuit to provide the target charging current to the driving capacitor so that the voltage of the driving capacitor reaches the first voltage value within the target rise time; The target charging current is negatively correlated with the target rise time.

17. The switching power supply adaptive driving device according to claim 16, characterized in that: The charging regulation circuit comprises: A switch circuit, N constant current sources and M auxiliary capacitors, N≥1, M≥0, N+M≥2, and N and M are both integers; The first end of the switch circuit is connected to all the constant current sources, the second end of the switch circuit is connected to all the auxiliary capacitors, and the third end of the switch circuit is connected to the second end of the driving capacitor; The constant current source is used to provide a constant current; The switch circuit is used to adjust its own path state according to the target rise time to select a first target number of constant current sources and a second target number of auxiliary capacitors to access the circuit, so that the first target number of constant current sources charges the drive capacitor and the second target number of auxiliary capacitors; The first target number is at least 1, the second target number is at least 0, the first target number is negatively correlated with the target rise time, and the second target number is positively correlated with the target rise time.

18. The switching power supply adaptive driving device according to claim 17, characterized in that: When N>1 and M=0, the switch circuit includes: Main switch, first switch circuit; One end of the first switch circuit is connected to the output ends of the n constant current sources, the other end of the first switch circuit is respectively connected to the output ends of the other constant current sources except the n constant current sources and one end of the main switch, the other end of the main switch is respectively connected to the second end of the driving capacitor and the control end of the first driving switch, and the control end of the first switch circuit is connected to the adjustment circuit; N>n≥1, n is an integer; The main switch is used to be turned on when charging the driving capacitor; The first switch circuit is used to adjust its own path state to select a third target number of constant current source access circuits, where the first target number minus the third target number=Nn.

19. The switching power supply adaptive driving device according to claim 17, characterized in that: When N=1 and M>0, the switch circuit includes: Main switch, second switch circuit; One end of the main switch is connected to all the constant current sources, one end of the second switch circuit is connected to the first ends of the m auxiliary capacitors, the other end of the second switch circuit is respectively connected to the first ends of the other auxiliary capacitors except the m auxiliary capacitors and the other end of the main switch, the second end of the drive capacitor and the control end of the first drive switch, the second ends of all the auxiliary capacitors are grounded, and the second end of the second switch circuit is connected to the adjustment circuit, M≥m>0, m is an integer; The main switch is used to be turned on when charging the driving capacitor; The second switch circuit is used to adjust its own path state to select a fourth target number of auxiliary capacitors to access the circuit, where the second target number minus the fourth target number=Mm.

20. The switching power supply adaptive driving device according to claim 17, characterized in that: When N>1 and M>0, the switch circuit includes: A main switch, a first switch circuit, and a second switch circuit; One end of the first switch circuit is connected to the output ends of the n constant current sources, the other end of the first switch circuit is respectively connected to the output ends of the other constant current sources except the n constant current sources and one end of the main switch, the other end of the main switch is respectively connected to the first end of the second switch circuit, the first ends of the other auxiliary capacitors except the m auxiliary capacitors, the second end of the driving capacitor and the control end of the first driving switch, the other end of the second switch circuit is connected to the m auxiliary capacitors, the second ends of all the auxiliary capacitors are grounded, and the control end of the first switch circuit and the control end of the second switch circuit are both connected to the adjustment circuit; N>n≥1, M≥m>0, m and n are integers; The main switch is used to be turned on when charging the driving capacitor; The first switch circuit is used to adjust its own path state to select a third target number of constant current source access circuits, where the first target number minus the third target number=Nn; The second switch circuit is used to adjust its own path state to select a fourth target number of auxiliary capacitors to access the circuit, where the second target number minus the fourth target number=Mm.

21. The switching power supply adaptive driving device according to claim 18 or 20, characterized in that: The first switch circuit comprises: n controllable switches, corresponding one to one with the n constant current sources, each controllable switch is arranged between the output end of the constant current source corresponding to itself and one end of the main switch, and the control end of each controllable switch is connected to the adjustment circuit; The driving circuit further includes: A control circuit connected to at least one of the n controllable switches, wherein the control circuit comprises a first comparator, a second comparator, a NAND gate and an OR gate; The first comparison voltage value is input to the positive input terminal of the first comparator, the preset conduction value is input to the negative input terminal of the first comparator and the positive input terminal of the second comparator, the second comparison voltage value is input to the negative input terminal of the second comparator, the output terminal of the first comparator and the output terminal of the second comparator are respectively connected to the two input terminals of the NAND gate, the output terminal of the NAND gate is connected to the first input terminal of the OR gate, the second input terminal of the OR gate is connected to the adjustment circuit, and the output terminal of the OR gate is connected to the control terminal of at least one controllable switch; The first comparison voltage value is greater than the second comparison voltage value.

22. The switching power supply adaptive driving device according to claim 19 or 20, characterized in that: The second switch circuit comprises: m sub-switch circuits, m third clamping circuits, and m resistors, and the m sub-switch circuits, the m third clamping circuits, the m resistors, and the m auxiliary capacitors correspond one to one; The first end of each of the sub-switch circuits is respectively connected to the first end of the auxiliary capacitor corresponding to itself, the first end of the third clamping circuit corresponding to itself, and the first end of the resistor corresponding to itself. The second end of each of the auxiliary capacitors and the second end of each of the third clamping circuits are grounded. The second end of each of the resistors inputs a preset clamping voltage. The control end of each of the sub-switch circuits is connected to the adjustment circuit.

23. The switching power supply adaptive driving device according to any one of claims 18 to 20, characterized in that: The driving circuit further includes: NOT gate, a third driving switch, a first clamping circuit, a second clamping circuit and a PWM output module; The first output end of the PWM output module is respectively connected to the input end of the NOT gate and the control end of the third drive switch, the output end of the NOT gate is connected to the control end of the main switch, the first end of the third drive switch is respectively connected to the first end of the first clamp circuit, the first end of the second clamp circuit, the second end of the drive capacitor and the control end of the first drive switch, the second end of the third drive switch, the second end of the first clamp circuit and the second end of the second clamp circuit are all grounded, and the second output end of the PWM output module is connected to the control end of the second drive switch; The signal levels outputted by the two output terminals of the PWM output module are opposite.

24. A switching power supply, characterized in that: It comprises a switching power supply adaptive driving device as described in any one of claims 14-23.

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