Power supply circuit, electronic equipment and current overshoot control method

Abstract

The invention provides a power supply circuit, electronic equipment and a current overshoot control method, the power supply circuit comprises a driving module, a power transistor and a voltage regulation module, the driving module responds to a first electrode voltage of a first electrode of the power transistor and a first reference voltage, and controls a control voltage of a control electrode of the power transistor; the voltage adjusting module responds to the control voltage not smaller than the preset voltage and controls the rise rate of the control voltage to be reduced. Therefore, the voltage regulation module can absorb the electric energy at the control electrode to control the rise rate of the control voltage to be reduced, so that the control voltage does not rise or slowly rise along with the electric energy absorbed away, the current in the power path is kept unchanged or slowly increased, and the current overshoot in the power path can be avoided.

Description

Technical Field

[0001] The present application relates to the technical field of power supplies, and particularly to a power supply circuit, an electronic device, and a method for controlling current overshoot. Background Art

[0002] When testing a power supply, it is necessary to connect the power supply to an electronic load to test whether the power supply can provide appropriate electrical energy for the electronic load. This kind of test can be called a power supply test. When the power supply circuit in the electronic load is connected to the power supply, the power supply circuit can control the voltage, current, or resistance output by the power supply by adjusting its own circuit, so as to test the performance of the power supply under different states. In other words, to test whether the power supply can provide a large current instantaneously, the power supply circuit is used as a load to increase the current from 0 to the target current instantaneously, and see whether the power supply can provide such a current to the power supply circuit, that is, whether there is such a current on the power path to meet the needs of the power supply circuit and realize the detection of the power supply ability.

[0003] With the increasing requirement for the power supply ability of the power supply to quickly respond to a large current, the current change rate (i.e., di / dt) of the current output by the power supply per unit time has increased to 5000 A / μs. However, due to the parasitic inductance of several hundred pf in the detection resistor in the power supply circuit, a serious overshoot of the load current occurs under a large di / dt, resulting in a situation that does not conform to the actual working scenario of the power supply. Summary of the Invention

[0004] The present application provides a power supply circuit, an electronic device, and a method for controlling current overshoot to avoid current overshoot in the power path.

[0005] In a first aspect, an embodiment of the present application provides a power supply circuit, which may include: a driving module, a power transistor, and a voltage regulation module; the driving module is respectively connected to the control electrode of the power transistor, the first electrode of the power transistor, and the voltage regulation module, and the driving module is configured to: in response to the first electrode voltage of the first electrode of the power transistor and the first reference voltage, control the control voltage of the control electrode of the power transistor; the first electrode of the power transistor is used to be connected to the ground terminal, and the second electrode of the power transistor is used to receive a power supply signal; the voltage regulation module is further connected to the control electrode of the power transistor, and the voltage regulation module is configured to: in response to the control voltage being not less than a preset voltage, control the rising rate of the control voltage to decrease. Wherein, the path formed after connecting the power supply, the second electrode of the power transistor, the first electrode of the power transistor, and the ground terminal is the power path. In this way, when processing the electric energy output by the power supply, the voltage regulation module can absorb the electric energy at the control electrode of the power transistor, so that the control voltage at the control electrode of the power transistor will no longer increase or increase slowly as the electric energy is absorbed, thereby reducing the rising rate of the control voltage, and the conduction degree of the power transistor remains unchanged or increases slowly. Finally, the current in the power path remains unchanged or increases slowly, avoiding the excessive increase of the current in the power path during the transient state, and thus can avoid the current overshoot in the power path.

[0006] It should be understood that when the power transistor is an N-type transistor, the control electrode may be the gate, the second electrode may be the drain, and the first electrode may be the source; when the power transistor is a P-type transistor, the control electrode may be the gate, the second electrode may be the source, and the first electrode may be the drain, which can be specifically set according to actual needs and will not be specifically limited herein.

[0007] Optionally, the voltage regulation module includes: a switching unit, a voltage regulation unit, and an RC network. The first end of the switching unit is connected to the control electrode of the power transistor, and the second end of the switching unit is respectively connected to the voltage regulation unit and the RC network. The voltage regulation unit is configured to: provide a second reference voltage to the second end of the switching unit, and the preset voltage is the sum of the second reference voltage and the conduction voltage drop of the switching unit. The switching unit is configured to: in response to the control voltage being not less than the preset voltage, conduct the control electrode of the power transistor to the RC network; in response to the control voltage being less than the preset voltage, disconnect the control electrode of the power transistor from the RC network. The RC network is configured to: in response to the control electrode of the power transistor being conducted to the RC network, control the rising rate of the control voltage to decrease; in response to the control electrode of the power transistor being disconnected from the RC network, not control the rising rate of the control voltage. In this way, the switching unit can control whether the control electrode of the power transistor is conducted to the RC network, and further control whether the RC network absorbs the electric energy at the control electrode of the power transistor, so as to avoid the overshoot of the current in the power path due to the too large rising speed of the control voltage. Moreover, the RC network does not always absorb the electric energy at the control electrode of the power transistor, but only absorbs the electric energy at the control electrode of the power transistor when the control electrode is conducted to the RC network, which is beneficial to avoiding the influence on the change rate of the current in the power path per unit time (which can be expressed as di / dt), so that on the basis of meeting the di / dt requirement, the overshoot of the current in the power path is avoided.

[0008] Among them, the preset voltage can be set as: the difference between the control voltage of the power transistor corresponding to the target current to be achieved in the power supply test and the conduction voltage drop of the switching unit when the power supply circuit is applied to the power supply test scenario. For example, if the control voltage of the power transistor corresponding to the target current is represented by Vm, and the conduction voltage drop of the switching unit is represented by Va, then the preset voltage can be Vm - Va. Moreover, the control voltage of the power transistor corresponding to the target current is the maximum value of the control voltage, so that the voltage regulation module can start to function when the control voltage reaches the maximum value, enabling the current in the power path to reach the target current, which can not only avoid the influence on di / dt, but also avoid the overshoot of the current in the power path, thereby improving the effect of the power supply test. It should be understood that the control voltage of the power transistor corresponding to the target current can be obtained from the pre-configured correspondence table of current and control voltage, and this correspondence table can be summarized according to actual experience. In the embodiments of the present application, the correspondence table is not specifically limited.

[0009] The switching unit may include a diode, and the anode of the diode is connected to the control electrode of the power transistor, and the cathode of the diode is respectively connected to the voltage regulating unit and the RC network. Thus, when the control voltage is not less than the preset voltage, the diode is turned on at this time, connecting the control electrode of the power transistor and the RC network, so that the electrical energy at the control electrode of the power transistor can be absorbed through the RC network; when the control voltage is less than the preset voltage, the diode is turned off at this time, disconnecting the control electrode of the power transistor and the RC network, and the RC network will not absorb the electrical energy at the control electrode of the power transistor. Thus, whether the RC network absorbs the electrical energy at the control electrode of the power transistor can be controlled through the diode. Among them, for the specific value of Va mentioned above, it can be determined according to the forward voltage drop of the selected diode, such as but not limited to 0.7V, and no specific limitation is made here.

[0010] The RC network may include: a first resistor and a first capacitor, and the first resistor and the first capacitor are connected in parallel between the second end of the switching unit and the ground terminal. Thus, when the diode is turned on, since the control voltage is higher than the ground voltage provided by the ground terminal, and the first capacitor is located between the control electrode and the ground terminal, part of the current at the control electrode will flow into the first capacitor to charge the first capacitor, thereby realizing the absorption of the electrical energy at the control electrode and realizing the function of the RC network. And when the diode is turned off, the first capacitor, the first resistor and the ground terminal form a loop, and the first capacitor releases the electrical energy through the first resistor until it is completely released, so as to continue to absorb the electrical energy at the control electrode when the diode is turned on again later.

[0011] The voltage regulating unit may include: a first digital-to-analog conversion circuit and a linear voltage regulator, and the linear voltage regulator is connected between the first digital-to-analog conversion circuit and the second end of the switching unit; the first digital-to-analog conversion circuit is used for: outputting a third reference voltage to the linear voltage regulator; the linear voltage regulator is used for: in response to the third reference voltage, providing a first reference voltage to the second end of the switching unit, so that the switching unit can determine whether to conduct according to the magnitude relationship between the control voltage and the preset voltage, thereby avoiding overshoot of the current on the power path. Among them, the first digital-to-analog conversion circuit can output a third reference voltage when processing the electrical energy output by the power supply, so as to avoid overshoot of the current on the power path, and when the first digital-to-analog conversion circuit does not process the electrical energy output by the power supply, it does not output a third reference voltage, which can reduce the power consumption of the first digital-to-analog conversion circuit, thereby reducing the power consumption of the power supply circuit.

[0012] Optionally, the power supply circuit may further include: a detection resistor, a voltage waveform conditioning module, and a current acquisition module. The voltage waveform conditioning module is respectively connected to the first end of the detection resistor, the second end of the detection resistor, and the current acquisition module; the first end of the detection resistor is further connected to the first pole of the power transistor, and the second end of the detection resistor is connected to the ground terminal; the voltage waveform conditioning module is configured to: after filtering the voltage across the detection resistor, output a voltage signal to the current acquisition module; the current acquisition module is configured to: in response to the voltage signal output by the voltage waveform conditioning module, acquire the current flowing through the detection resistor. Since there is a parasitic inductance in the detection resistor when acquiring the current in the power path, there will be a difference between the acquired current and the actual current. The larger the parasitic inductance, the greater the difference, ultimately resulting in inaccurate acquired current. Under the action of the voltage waveform conditioning module, the inductance signal of the parasitic inductance can be filtered to eliminate the influence of the parasitic inductance, making the acquired current closer to the actual current and reducing the acquisition error.

[0013] Wherein, the voltage waveform conditioning module may include: a second resistor, a third resistor, and a second capacitor. The second resistor is respectively connected to the first end of the detection resistor, the first end of the second capacitor, and the current acquisition module, and the third resistor is respectively connected to the second end of the detection resistor, the second end of the second capacitor, and the current acquisition module. In this way, by setting the resistance values of the second resistor and the third resistor, and the capacitance value of the second capacitor, the inductance signal of the parasitic inductance can be filtered, thereby eliminating the influence of the parasitic inductance. It should be understood that the specific settings of the resistance values of the second resistor and the third resistor, and the capacitance value of the second capacitor can be set according to the actual situation and are not specifically limited herein.

[0014] Optionally, the current acquisition module may include: a second operational amplifier and an analog-to-digital converter. The positive input terminal of the second operational amplifier is respectively connected to one end of the second resistor and the first end of the second capacitor, the negative input terminal of the second operational amplifier is respectively connected to one end of the third resistor and the second end of the second capacitor, and the output terminal of the second operational amplifier is connected to the analog-to-digital converter. The second operational amplifier is configured to: determine the voltage difference between the voltage signals input from the positive input terminal and the negative input terminal, and then divide it by the resistance value of the detection resistor to determine the current signal, and output the current signal to the analog-to-digital converter, so that the analog-to-digital converter converts the received current signal into a current value, thereby realizing the acquisition of the current.

[0015] Optionally, the driving module may include: a first operational amplifier, an adjustment circuit, and a second digital-to-analog conversion circuit. The adjustment circuit is respectively connected to the second digital-to-analog conversion circuit and the positive input terminal of the first operational amplifier. The negative input terminal of the first operational amplifier is respectively connected to the first pole of the power transistor and the first end of the detection resistor. The output terminal of the first operational amplifier is connected to the control pole of the power transistor. The second digital-to-analog conversion circuit is configured to: in response to processing the electric energy output by the power supply, output a fourth reference voltage. The adjustment circuit is configured to: adjust the fourth reference voltage so as to output a second reference voltage to the positive input terminal of the first operational amplifier, and the second reference voltage is a stable voltage value, so that the first operational amplifier processes the output voltage based on this reference. The first operational amplifier is configured to: according to the comparison result such as the difference between the second reference voltage and the output voltage (i.e., the voltage of the first pole of the power transistor), output a control voltage to the control pole of the power transistor. Therefore, through the coordinated action of the second digital-to-analog conversion circuit, the adjustment circuit, and the first operational amplifier, in response to processing the electric energy output by the power supply and the comparison result between the voltage of the first pole of the power transistor and the second reference voltage, the control voltage of the control pole of the power transistor can be controlled; and the fourth reference voltage can be determined according to the target current that the current in the power path is to reach, so that the control voltage corresponds to the target current.

[0016] Based on the above structure, taking the preset voltage as the sum of the first reference voltage and the forward voltage drop of the diode as an example, the working principle of the power supply circuit may include:

[0017] When processing the electric energy output by the power supply, the voltage signal output at the output terminal of the first operational amplifier is a square wave signal. When the rising edge of the square wave signal arrives, that is, when the processing starts, the control voltage of the power transistor increases rapidly. When it reaches its own threshold voltage, the power transistor turns on, and as the control voltage increases, the conduction degree of the power transistor also gradually increases. If the control voltage is less than the preset voltage, the diode is cut off at this time, and the RC network does not function and does not absorb the voltage at the control electrode, so the current in the power path rises rapidly. If the voltage at the control electrode is not less than the preset voltage, the diode conducts at this time, the RC network starts to function and absorbs the electric energy at the control electrode, and uses the absorbed current to charge the first capacitor in the RC network, which makes the control voltage no longer rise or slow down as the electric energy is absorbed, so that the current in the power path remains unchanged or increases slowly. When the control voltage rises to the maximum value, the conduction degree of the power transistor is constant and remains unchanged, and the current in the power path no longer rises, thus avoiding the overshoot of the current in the power path under dynamic conditions. Moreover, as the first capacitor is fully charged, the absorption effect of the RC network reaches its limit, and the RC network will no longer absorb electric energy. When the falling edge of the square wave signal arrives, the control voltage gradually decreases until the control voltage is less than the preset voltage, and the diode changes from conduction to cut-off. At this time, the first capacitor will release the stored electric energy through the first resistor. After that, the above process is executed every time the rising edge and the falling edge of the square wave signal arrive.

[0018] Furthermore, when testing the power supply capacity of the power supply, the maximum value of the control voltage can be determined according to the target current to be achieved by the current in the power path, and the target current can be determined according to the actual test requirements, so the maximum value of the control voltage can be determined based on the target current. And in order to ensure that the current rises rapidly during the test and di / dt is not affected by the RC network, the preset voltage can be dynamically set according to the maximum value of the control voltage. By matching a suitable preset voltage, the RC network can be made to function only when the control voltage reaches the maximum value. So the diode conducts only when the control voltage reaches the maximum value, and at this time the RC network will absorb the electric energy at the control electrode, thus achieving the purpose of neither affecting the rapid rise of the current nor absorbing the overshoot. Based on this, the maximum value of the control voltage can be dynamically set according to the target current, and then the preset voltage can be dynamically set according to the maximum value of the control voltage to ensure that the current rises rapidly and di / dt is not affected by the RC network, improving the effect of the power supply test.

[0019] In addition, a voltage waveform conditioning module composed of a second resistor, a third resistor, and a second capacitor can effectively filter out the influence of the parasitic inductance in the detection resistor, so that the voltage signals transmitted to the positive input terminal and the negative input terminal of the second operational amplifier are voltage signals from which the inductance signals have been filtered out. Furthermore, the second operational amplifier can determine the current signal and output the current signal to the analog-to-digital converter, enabling the analog-to-digital converter to convert the received current signal into a current value, realizing the acquisition of the current, and the acquired current is closer to the true current, reducing the acquisition error.

[0020] In a second aspect, an embodiment of the present application further provides a power supply circuit, which may include: a driving module, a power transistor, and a voltage regulation module; the driving module is respectively connected to the control electrode of the power transistor, the first electrode of the power transistor, and the voltage regulation module. The driving module is configured to: in response to the first electrode voltage of the power transistor and a first reference voltage, control the control voltage of the control electrode of the power transistor; the first electrode of the power transistor is used to be connected to the ground terminal, and the second electrode of the power transistor is used to receive a power supply signal; the voltage regulation module includes: a switching unit, a voltage regulation unit, and an RC network. The first end of the switching unit is connected to the control electrode of the power transistor, and the second end of the switching unit is respectively connected to the voltage regulation unit and the RC network; the voltage regulation unit is configured to: provide a second reference voltage to the second end of the switching unit, and a preset voltage is the sum of the second reference voltage and the conduction voltage drop of the switching unit; the switching unit is configured to: in response to the control voltage being not less than the preset voltage, conduct the control electrode of the power transistor and the RC network; the RC network is configured to: in response to the control electrode of the power transistor being conducted with the RC network, control the rising rate of the control voltage to decrease.

[0021] In this way, when processing the electric energy output by the power supply, under the action of the switching unit, the voltage regulation unit, and the RC network, the electric energy at the control electrode of the power transistor can be absorbed, so that the control voltage at the control electrode of the power transistor will no longer increase or increase slowly as the electric energy is absorbed, thereby reducing the rising rate of the control voltage, and the conduction degree of the power transistor remains unchanged or increases slowly. Finally, the current in the power path remains unchanged or increases slowly, avoiding excessive increase of the current in the power path, and thus the current overshoot in the power path can be avoided.

[0022] Optionally, the power supply circuit further includes: a detection resistor, a voltage waveform conditioning module, and a current acquisition module. The voltage waveform conditioning module is connected to the first end of the detection resistor, the second end of the detection resistor, and the current acquisition module respectively; the first end of the detection resistor is further connected to the first pole of the power transistor, and the second end of the detection resistor is connected to the ground terminal; the voltage waveform conditioning module includes: a second resistor, a third resistor, and a second capacitor. The second resistor is connected to the first end of the detection resistor, the first end of the second capacitor, and the current acquisition module respectively, and the third resistor is connected to the second end of the detection resistor, the second end of the second capacitor, and the current acquisition module respectively; the current acquisition module is configured to: in response to the signal processed by the voltage waveform conditioning module, acquire the current flowing through the detection resistor. In this way, under the action of the second resistor, the third resistor, and the second capacitor, the inductance signal in the voltage across the detection resistor collected can be filtered, the influence of the parasitic inductance is eliminated, the collected current is closer to the real current, and the acquisition error is reduced.

[0023] It should be understood that since the principle of the power supply circuit for solving the problem is similar to that of the foregoing power supply circuit, the similarities in the structure between the power supply circuit and the power supply circuit described in the foregoing first aspect, such as but not limited to: the driving module, the preset voltage, the switching unit, the RC network, the voltage regulating unit, and the specific setting manner of the current acquisition module, can all refer to the implementation and technical effects of the foregoing power supply circuit, and the repeated parts will not be described again.

[0024] In a third aspect, an embodiment of the present application further provides a method for controlling current overshoot. The method is implemented by using the first aspect and any one of the embodiments in the first aspect, or by using the second aspect and any one of the embodiments in the second aspect. The control method may include: the driving module controls the control voltage of the control pole of the power transistor in response to the first pole voltage of the first pole of the power transistor and the first reference voltage; the voltage regulation module controls the rising rate of the control voltage to decrease in response to the control voltage being not less than the preset voltage. In this way, since the voltage regulation module absorbs the electric energy at the control pole, the control voltage at the control pole will no longer increase or increase slowly as the electric energy is absorbed, thereby reducing the rising rate of the control voltage, and the conduction degree of the power transistor remains unchanged or increases slowly. Finally, the current in the power path remains unchanged or increases slowly, avoiding the excessive increase of the current in the power path during the transient state, and thus avoiding the current overshoot in the power path.

[0025] Optionally, the control method may further include: after the voltage waveform conditioning module filters the voltage across the detection resistor, it outputs a voltage signal to the current acquisition module; the current acquisition module acquires the current flowing through the detection resistor in response to the voltage signal output by the voltage waveform conditioning module. In this way, the influence of the parasitic inductance in the detection resistor on the acquired current can be eliminated, making the acquired current closer to the true current and reducing the acquisition error.

[0026] Optionally, the preset voltage may be: when the power supply circuit is applied to a power supply test scenario, and the voltage regulation module includes a switch unit, a voltage regulation unit, and an RC network, with the first end of the switch unit connected to the control electrode of the power transistor and the second end of the switch unit connected to the voltage regulation unit and the RC network respectively, the difference between the control voltage of the power transistor corresponding to the target current to be achieved in the power supply test and the conduction voltage drop of the switch unit. In this way, the control voltage of the power transistor corresponding to the target current is the maximum value of the control voltage. In this way, the voltage regulation module starts to function only when the control voltage reaches the maximum value, enabling the current in the power path to reach the target current. This can not only avoid affecting di / dt but also avoid overshoot of the current in the power path, thereby improving the effect of the power supply test.

[0027] It should be understood that since the principle of the control method for solving problems is similar to that of the foregoing power supply circuit for solving problems, the implementation and technical effects of the control method can refer to the implementation and technical effects of the foregoing power supply circuit, and the repeated parts will not be elaborated.

[0028] In a fourth aspect, an embodiment of the present application further provides an electronic device, which may include: a power supply circuit and a circuit board as described in the first aspect and any one of the embodiments in the first aspect, or as described in the second aspect and any one of the embodiments in the second aspect. The power supply circuit is disposed on the circuit board and electrically connected to the circuit board. In this way, when applied to a power supply test scenario, the electronic device may include an electronic load, and the electronic load can be used to test the power supply ability of the power supply; when applied to a power supply scenario, the electronic device may include: devices including a power supply such as a smart phone, a smart TV, a smart TV set-top box, a smart watch, a personal computer (PC), a wearable device, a smart broadband, etc., which will not be listed one by one here. The power supply circuit in the electronic device can output stable electric energy, enabling the electronic device to operate normally.

[0029] It should be understood that since the principle of the electronic device for solving problems is similar to that of the foregoing power supply circuit for solving problems, the implementation and technical effects of the electronic device can refer to the implementation and technical effects of the foregoing power supply circuit, and the repeated parts will not be elaborated. Description of the Drawings

[0030] Figure 1 Schematic diagram of a structure of an electronic device in the prior art;

[0031] Figure 2 Schematic diagram of a structure of a power supply circuit provided by an embodiment of the present application;

[0032] Figure 3 Comparison diagram of power supply test effects;

[0033] Figure 4 Schematic diagram of another structure of a power supply circuit provided by an embodiment of the present application;

[0034] Figure 5 Relationship diagram of detection resistance and parasitic inductance provided by an embodiment of the present application;

[0035] Figure 6 Flowchart of a method for controlling current overshoot provided by an embodiment of the present application. Detailed implementation manners

[0036] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings.

[0037] It should be noted that the same reference numerals in the drawings of the present application denote the same or similar structures, and thus their repeated descriptions will be omitted. The words expressing positions and directions described in the present application are all illustrated by taking the drawings as examples, but can be changed according to needs, and all the changes made are included in the protection scope of the present application. The drawings of the present application are only used to illustrate the relative position relationship and do not represent the true scale.

[0038] The technical solutions provided by the embodiments of the present application can be applied to various electronic devices, and the technical solutions provided by the embodiments of the present application can be applied to any scenario that needs to achieve a high di / dt dynamic response, such as but not limited to a power supply test scenario, a power supply scenario, etc., which are not specifically limited herein. Among them, in the power supply scenario, the electronic device may include but is not limited to: a smart phone, a smart TV, a smart TV set-top box, a smart watch, a personal computer, a wearable device, a smart broadband, etc. devices including a power supply, which are not listed one by one here. The electronic device includes: a power supply circuit, a power supply, and an electrical appliance component. The power supply circuit processes the electric energy output by the power supply and then outputs it to the electrical appliance component, so that the electrical appliance component can work normally and the normal operation of the electronic device can be realized.

[0039] In a power supply test scenario, an electronic device may include an electronic load, and the power supply is connected to the electronic load to test whether the power supply can provide appropriate electrical energy for the electronic load. This test can be called a power supply test (also called a loading test). The electronic load includes a power supply circuit. When the power supply circuit is connected to the power supply, the power supply circuit can control the voltage, current, or resistance output by the power supply by adjusting its own circuit, so as to test the performance of the power supply under different conditions. In other words, to test whether the power supply can provide a large current instantaneously, the power supply circuit is used as a load to increase the current from 0 to the target current instantaneously, and see whether the power supply can provide such a current to the power supply circuit, that is, whether there is such a current on the power path to meet the needs of the power supply circuit and realize the detection of the power supply's power supply ability.

[0040] Figure 1 An exemplary structural schematic diagram of an electronic device in the prior art is shown. See Figure 1 As shown, the electronic device may include: a power supply circuit and a circuit board 100. The power supply circuit is disposed on the circuit board 100, and the power supply circuit is electrically connected to the circuit board 100 ( Figure 1 The electrical connection relationship is not shown in the figure). Taking the application in a power supply test scenario as an example, the power supply circuit includes: a second digital-to-analog conversion circuit 10, an adjustment circuit 20, a first operational amplifier OP1, a power transistor NMOS, a detection resistor R0, a second operational amplifier OP2, and an analog-to-digital converter 30. Among them, the gate of the power transistor NMOS is connected to the output terminal of the first operational amplifier OP1, the drain of the power transistor NMOS is connected to the power supply 40, and the source of the power transistor NMOS is respectively connected to the negative input terminal of the first operational amplifier OP1, the first end of the detection resistor R0, and the positive input terminal of the second operational amplifier OP2. The adjustment circuit 20 is respectively connected to the second digital-to-analog conversion circuit 10 and the positive input terminal of the first operational amplifier OP1. The second end of the detection resistor R0 is respectively connected to the ground terminal GND and the negative input terminal of the second operational amplifier OP2. The output terminal of the second operational amplifier OP2 is connected to the analog-to-digital converter 30.

[0041] At this time, the second digital-to-analog conversion circuit 10 functions as a waveform generator and is used for: in response to testing the power supply capacity of the power supply 40, outputting a fourth reference voltage; the adjustment circuit 20 is used for: adjusting the fourth reference voltage so as to output a stable first reference voltage to the positive input terminal of the first operational amplifier OP1; the first operational amplifier OP1 is used for: according to the difference between the first reference voltage and the output voltage V0, outputting a gate voltage to the gate of the power transistor NMOS; for the power transistor NMOS: when the gate voltage is less than its own threshold voltage, the power transistor NMOS is turned off, and when the path formed by the source, drain, detection resistor R0 and the ground terminal GND of the power transistor NMOS is the power path, the power path is turned off and no current passes through; when the gate voltage is not less than its own threshold voltage, the power transistor NMOS is turned on, so that the power path is turned on and a current I0 (i.e., the load current) passes through, and the current I0 is provided by the power supply 40. The second operational amplifier OP2 is used for collecting the voltage across the detection resistor R0, and after determining the voltage difference, dividing it by the resistance value of the detection resistor R0, the current signal can be obtained and transmitted to the analog-to-digital converter 30; the analog-to-digital converter 30 is used for converting the current signal into a current value, so as to realize the detection of the current I0 on the power path, determine the load current, and thus determine the power supply capacity of the power supply 40.

[0042] As the current I0 passes through the power path, the output voltage V0 gradually increases, so that the gate voltage output by the first operational amplifier OP1 gradually increases, and further the conduction degree of the power transistor NMOS gradually increases, which is reflected in the power path as the passing current I0 also increases accordingly. Therefore, the voltage can be fed back to the negative input terminal of the first operational amplifier OP1 according to the current in the power path, and then the gate voltage output by the first operational amplifier OP1 can be regulated so that the current in the power path meets the requirements.

[0043] Currently, with the increasing requirement for the power supply capacity of the power supply 40 to quickly respond to large currents, the current change rate (i.e., di / dt) of the current output by the power supply 40 per unit time has increased to 5000 A / μs. However, due to the parasitic inductance of several hundred pf in the detection resistor R0, a serious overshoot of the load current occurs under a large di / dt, resulting in a situation that does not conform to the actual working scenario of the power supply 40.

[0044] Based on this, in order to solve the above problems, the embodiment of the present application provides a power supply circuit for avoiding the overshoot of the current I0 in the power path.

[0045] The following will be explained and described in conjunction with specific embodiments and taking the power transistor as an N-type transistor as an example.

[0046] Figure 2The schematic structural diagram of a power supply circuit provided by the present application is exemplarily shown. Refer to Figure 2 As shown, the power supply circuit may include: a driving module M1, a power transistor NMOS, a detection resistor R0, and a voltage regulation module 50; the driving module M1 is respectively connected to the gate of the power transistor NMOS, the source of the power transistor NMOS, and the voltage regulation module 50. The drain of the power transistor NMOS is connected to the power supply 40. The source of the power transistor NMOS is further connected to the first end of the detection resistor R0. The second end of the detection resistor R0 is connected to the ground terminal GND. The power supply 40, the drain of the power transistor NMOS, the source of the power transistor NMOS, the detection resistor R0, and the ground terminal GND are sequentially connected to form a power path.

[0047] The driving module M1 includes a second digital-to-analog conversion circuit 10, an adjustment circuit 20, and a first operational amplifier OP1. The adjustment circuit 20 is respectively connected to the second digital-to-analog conversion circuit 10 and the positive input terminal of the first operational amplifier OP1. The negative input terminal of the first operational amplifier OP1 is respectively connected to the source of the power transistor NMOS and the first end of the detection resistor R0. The output terminal of the first operational amplifier OP1 is respectively connected to the gate of the power transistor NMOS and the voltage regulation module 50.

[0048] At this time, the second digital-to-analog conversion circuit 10 is configured to: in response to processing the electric energy output by the power supply 40, output a fourth reference voltage; the adjustment circuit 20 is configured to: adjust the fourth reference voltage so as to output a first reference voltage to the positive input terminal of the first operational amplifier OP1; the first operational amplifier OP1 is configured to: according to the comparison result of the first reference voltage and the output voltage V0, such as the difference, output a gate voltage to the gate of the power transistor NMOS; therefore, through the cooperation of the second digital-to-analog conversion circuit 10, the adjustment circuit 20 and the first operational amplifier OP1, in response to processing the electric energy output by the power supply 40, and the comparison result of the source voltage (i.e., the output voltage V0) of the power transistor NMOS and the first reference voltage, the gate voltage of the power transistor NMOS can be controlled. The power transistor NMOS is configured to: conduct when the gate voltage is not less than the threshold voltage of the power transistor NMOS, thereby enabling the power path (i.e., the path formed by sequentially connecting the power supply 40, the drain of the power transistor NMOS, the source of the power transistor NMOS, the detection resistor R0, and the ground terminal GND) to conduct; disconnect when the gate voltage is less than the threshold voltage, thereby enabling the power path to disconnect. The voltage adjustment module 50 is configured to: control the rising rate of the gate voltage to decrease in response to the gate voltage not less than a preset voltage; and not control the rising rate of the gate voltage in response to the gate voltage being less than the preset voltage. It should be understood that when applied to a power supply test scenario, processing the electric energy output by the power supply 40 includes testing the power supply capacity of the power supply 40; or, when applied to a power supply scenario, processing the electric energy output by the power supply 40 includes adjusting the voltage output by the power supply 40. And when the gate voltage is not less than the preset voltage, the gate voltage will not be less than the threshold voltage of the power transistor NMOS, so when the gate voltage is not less than the preset voltage, the power transistor NMOS is in a conducting state.

[0049] In this way, when processing the electric energy output by the power supply 40, the voltage adjustment module 50 can absorb the electric energy at the gate of the power transistor NMOS, so that the gate voltage at the gate of the power transistor NMOS will no longer increase or increase slowly as the electric energy is absorbed, thereby reducing the rising rate of the gate voltage, and the conduction degree of the power transistor NMOS remains unchanged or increases slowly. Finally, the current I0 in the power path remains unchanged or increases slowly, avoiding the excessive increase of the current I0 in the power path during the transient state, and thus can avoid the overshoot of the current I0 in the power path.

[0050] Next, the structure of the voltage adjustment module 50 will be introduced.

[0051] The voltage regulation module 50 may include: a switching unit 51, a voltage regulation unit 53, and an RC network 52. The first end of the switching unit 51 is connected to the gate of the power transistor NMOS, and the node at the connection is node A. The second end of the switching unit 51 is respectively connected to the voltage regulation unit 53 and the RC network 52, and the node at the connection is node B. Among them, the voltage regulation unit 53 is used to: provide a second reference voltage to the second end of the switching unit 51 (i.e., node B), and the preset voltage is the sum of the second reference voltage and the on-voltage drop of the switching unit 51. The switching unit 51 is used to: in response to the gate voltage of the power transistor NMOS being not less than the preset voltage, conduct the gate of the power transistor NMOS with the RC network 52, that is, make node A and node B conduct; in response to the gate voltage of the power transistor NMOS being less than the preset voltage, disconnect the gate of the power transistor NMOS from the RC network 52, that is, make node A and node B not conduct. The RC network 52 is used to: in response to the gate of the power transistor NMOS being conducted with the RC network 52, that is, node A and node B conduct, absorb the electrical energy at the gate of the power transistor NMOS, and this electrical energy can be understood as current, so as to control the rising rate of the gate voltage of the power transistor NMOS to decrease; in response to the gate of the power transistor NMOS being disconnected from the RC network 52, that is, node A and node B not conduct, not absorb the electrical energy at the gate of the power transistor NMOS, so as not to control the rising rate of the gate voltage of the power transistor NMOS. In this way, the switching unit 51 can control whether the gate of the power transistor NMOS is conducted with the RC network 52, and further control whether the RC network 52 absorbs the electrical energy at the gate of the power transistor NMOS, so as to avoid the overshoot of the current I0 on the power path due to the too large rising speed of the gate voltage. Moreover, the RC network 52 does not always absorb the electrical energy at the gate of the power transistor NMOS, but only absorbs the electrical energy at the gate of the power transistor NMOS when the gate is conducted with the RC network 52, which is beneficial to avoiding the influence on the change rate of the current I0 on the power path per unit time (which can be expressed as di / dt), so as to avoid the overshoot of the current I0 on the power path while meeting the di / dt requirement.

[0052] Among them, the switching unit 51 may include a diode D, and the positive electrode of the diode D is connected to the gate of the power transistor NMOS. The negative electrode of the diode D is respectively connected to the voltage regulating unit 53 and the RC network 52. That is, the positive electrode of the diode D is connected to the node A, and the negative electrode of the diode D is connected to the node B. In this way, when the gate voltage is not less than the preset voltage, the diode D is turned on at this time, so that the node A and the node B are turned on, and the gate of the power transistor NMOS and the RC network 52 are connected. Thus, the electrical energy at the gate of the power transistor NMOS can be absorbed through the RC network 52; when the gate voltage is less than the preset voltage, the diode D is turned off at this time, so that the node A and the node B are not turned on, and the gate of the power transistor NMOS and the RC network 52 are disconnected. The RC network 52 will not absorb the electrical energy at the gate of the power transistor NMOS. Thus, whether the RC network 52 absorbs the electrical energy at the gate of the power transistor NMOS can be controlled through the diode D. Among them, when the switching unit 51 includes the diode D, the preset voltage can be set as: when the power supply circuit is applied to the power supply test scenario, the difference between the gate voltage of the power transistor NMOS corresponding to the target current to be achieved in the power supply test and the conduction voltage drop of the diode D. For example, if the gate voltage of the power transistor NMOS corresponding to the target current is represented by Vm, and the conduction voltage drop of the diode D is represented by Va, then the preset voltage can be Vm - Va. And the gate voltage of the power transistor NMOS corresponding to the target current is the maximum value of the gate voltage. In this way, the voltage regulation module 50 can start to function only when the gate voltage reaches the maximum value, so that the current I0 on the power path during the power supply test can reach the target current, which can not only avoid affecting di / dt, but also avoid overshoot of the current I0 on the power path, thereby improving the effect of the power supply test. For the specific value of Va, it can be determined according to the selected diode D, such as but not limited to 0.7V, and no specific limitation is made here.

[0053] The RC network 52 may include: a first resistor R1 and a first capacitor C1. The first resistor R1 and the first capacitor C1 are connected in parallel between the second end of the switching unit 51 and the ground terminal GND. That is, the first resistor R1 and the first capacitor C1 are connected in parallel between the node B and the ground terminal GND. In this way, when the diode D is turned on to make the node A and the node B turned on, because the gate voltage at the node A is higher than the ground voltage provided by the ground terminal GND, and the first capacitor C1 is located between the node A and the ground terminal GND, so part of the current at the node A will flow into the first capacitor C1 to charge the first capacitor C1, thus realizing the absorption of the electrical energy at the node A and realizing the function of the RC network 52. And when the node A and the node B are disconnected, the first capacitor C1, the first resistor R1, the node B and the ground terminal GND form a loop, and the first capacitor C1 releases electrical energy through the first resistor R1 until it is completely released, so as to continue to absorb the electrical energy at the node A when the node A and the node B are turned on again later.

[0054] The voltage regulation unit 53 may include: a first digital-to-analog conversion circuit 53a and a linear voltage regulator 53b. The linear voltage regulator 53b is connected between the first digital-to-analog conversion circuit 53a and the second end of the switch unit 51, that is, the linear voltage regulator 53b is connected between the first digital-to-analog conversion circuit 53a and node B. The first digital-to-analog conversion circuit 53a is configured to: in response to processing the electric energy output by the power supply 40, output a third reference voltage to the linear voltage regulator 53b. The linear voltage regulator 53b is configured to: in response to the third reference voltage, provide a second reference voltage to the second end of the switch unit 51, so that the diode D can determine whether to conduct according to the magnitude relationship between the gate voltage and the preset voltage, thereby avoiding overshoot of the current I0 on the power path.

[0055] Based on this, the working principle of the power supply circuit may include:

[0056] When processing the electric energy output by the power supply 40, the voltage signal output by the output terminal of the first operational amplifier OP1 is a square wave signal. When the rising edge of the square wave signal arrives, that is, at the beginning of the processing, the gate voltage of the power transistor NMOS (i.e., the voltage at node A) rapidly increases. When it reaches its own threshold voltage, the power transistor NMOS conducts, and as the gate voltage increases, the conduction degree of the power transistor NMOS also gradually increases. If the voltage at node A is less than the sum of the voltage at node B and the forward voltage drop of the diode D, it indicates that the gate voltage is less than the preset voltage. At this time, the diode D is cut off, and the RC network 52 does not function and does not absorb the electric energy at node A. Furthermore, the current I0 on the power path rapidly rises. If the voltage at node A is not less than the sum of the voltage at node B and the forward voltage drop of the diode D, it indicates that the gate voltage is not less than the preset voltage. At this time, the diode D conducts, and the RC network 52 starts to function and absorbs the electric energy at node A, and uses the absorbed electric energy to charge the first capacitor C1 in the RC network 52. This causes the voltage at node A (i.e., the gate voltage) to no longer increase or increase slowly as the electric energy is absorbed, that is, the rising rate of the voltage at node A decreases, and further causes the current I0 in the power path to remain unchanged or increase slowly. When the gate voltage rises to the maximum value, the conduction degree of the power transistor NMOS is constant and remains unchanged, and the current I0 on the power path no longer rises, thus achieving the avoidance of overshoot of the current I0 on the power path in the dynamic case. And, as the first capacitor C1 is fully charged, the absorption effect of the RC network 52 reaches the limit, and the RC network 52 will no longer continue to absorb electric energy. When the falling edge of the square wave signal arrives, the gate voltage gradually decreases until the gate voltage is less than the preset voltage, and then the diode D changes from conduction to cut-off. At this time, the first capacitor C1 will release the stored electric energy through the first resistor R1.

[0057] Further, when testing the power supply capacity of the power supply 40, the maximum value of the gate voltage can be determined according to the target current that the current I0 in the power path is to reach, and the target current can be determined according to the actual test requirements. Therefore, the maximum value of the gate voltage can be determined based on the target current. Moreover, in order to ensure that the current I0 rises rapidly during the test and di / dt is not affected by the RC network 52, the preset voltage can be dynamically set according to the maximum value of the gate voltage, that is, the voltage at node B is dynamically set according to the maximum value of the gate voltage at node A. By matching the appropriate preset voltage, the RC network 52 can be made to function only when the gate voltage reaches the maximum value, that is, the preset voltage is set to the difference between the maximum value reached by the gate voltage and the conduction voltage drop of the diode D. Therefore, the diode D conducts only when the gate voltage reaches the maximum value, and at this time, the RC network 52 will absorb the electrical energy at the gate, so that the purpose of not affecting the rapid rise of the current I0 and absorbing the overshoot can be achieved. Based on this, the maximum value of the gate voltage can be dynamically set according to the target current, and then the preset voltage can be dynamically set according to the maximum value of the gate voltage to ensure that the current I0 rises rapidly and di / dt is not affected by the RC network 52, improving the test effect.

[0058] As Figure 3 shown in the figure, (a) in the figure shows the current change in the power path when the power supply circuit in the prior art tests the power supply capacity of the power supply 40, and (b) to (d) in the figure all show the current change in the power path when the power supply circuit in the embodiment of the present application tests the power supply capacity of the power supply 40. It can be clearly seen from the figure that when the voltage adjustment module 50 is not provided, the overshoot phenomenon of the current I0 in the power path is obvious, as shown in the virtual circle 1 in (a); under the action of the voltage adjustment module 50, the overshoot phenomenon of the current I0 in the power path has been significantly improved, indicating that the overshoot of the current I0 has been better suppressed, as shown in (b) to (d), and di / dt is not affected. Moreover, the current changes corresponding to different preset voltages are given in the figures (b) to (d), and the preset voltage corresponding to the figure (b) is greater than the preset voltage corresponding to the figure (c), the preset voltage corresponding to the figure (c) is greater than the preset voltage corresponding to the figure (d), and the preset voltage corresponding to the figure (d) is the difference between the maximum value reached by the gate voltage and the conduction voltage drop of the diode D; from the results shown in the figures (b) to (d), it can be seen that when the preset voltage is the difference between the maximum value reached by the gate voltage and the conduction voltage drop of the diode D, the overshoot phenomenon of the current can be effectively eliminated; when the preset voltage is greater than the difference between the maximum value reached by the gate voltage and the conduction voltage drop of the diode D, it means that when the gate voltage reaches the maximum value, the diode is still in the cut-off state, and the RC network will not absorb the electrical energy at the gate. Only when the gate voltage reaches the sum of the preset voltage and the conduction voltage drop of the diode D will the diode conduct. Therefore, the overshoot phenomenon of the current will also be improved to a certain extent, as shown in the virtual circles 2 and 3.

[0059] Exemplarily, the power supply circuit may further include a current acquisition module M2. The current acquisition module M2 can acquire the current I0 on the power path. The current acquisition module M2 includes a second operational amplifier OP2 and an analog-to-digital converter 30. The positive input terminal of the second operational amplifier OP2 is connected to the first end of the detection resistor R0, the negative input terminal of the second operational amplifier OP2 is connected to the second end of the detection resistor R0, and the output terminal of the second operational amplifier OP2 is connected to the analog-to-digital converter 30. The second operational amplifier OP2 can acquire the voltage across the detection resistor R0, and after determining the pressure difference, divide it by the resistance value of the detection resistor R0 to obtain a current signal. The analog-to-digital converter 30 converts the current signal into a current value, thereby realizing the detection of the current I0 on the power path, determining the load current, and thus determining the power supply capacity of the power supply 40.

[0060] Figure 4 Exemplarily, a schematic structural diagram of a power supply circuit provided by the present application is shown. Refer to Figure 4 As shown, the structure of the power supply circuit in this embodiment is basically similar to that of the power supply circuit in the foregoing Figure 2 As shown in the embodiment. The difference is that the power supply circuit further includes a voltage waveform conditioning module 60. Exemplarily, the detection resistor R0 has parasitic inductance, which is not shown in Figure 4 . When acquiring the current I0 on the power path, due to the existence of the parasitic inductance, there is a difference between the acquired current I0 and the actual current. The larger the parasitic inductance, the greater the difference, resulting in inaccurate acquisition of the current I0. It should be understood that since the current I0 in the power path changes, the acquired current I0 can be considered a dynamic current. Based on this, to solve this problem, the power supply circuit may further include: a voltage waveform conditioning module 60, which is respectively connected to the first end of the detection resistor R0, the second end of the detection resistor R0, the positive input terminal and the negative input terminal of the second operational amplifier OP2. The voltage waveform conditioning module 60 is used for: after filtering the voltage across the detection resistor R0, outputting voltage signals to the positive input terminal and the negative input terminal of the second operational amplifier OP2 respectively. In other words, the voltage waveform conditioning module 60 can filter the inductance signal in the voltage across the detection resistor R0. The second operational amplifier OP2 determines the pressure difference input to the positive input terminal and the negative input terminal and then divides it by the resistance value of the detection resistor R0 to determine a current signal and output the current signal to the analog-to-digital converter 30, so that the analog-to-digital converter 30 converts the received current signal into a current value, thereby realizing the acquisition of the current I0. After the filtering process of the voltage waveform conditioning module 60, the acquired current I0 is closer to the actual current, reducing the acquisition error.

[0061] For example, when testing the power supply capacity of the power supply 40, the gate voltage output by the first operational amplifier OP1 can be determined according to the relationship between the collected current and the preset target current. When it is necessary to test a transient current of 5000 A / μs and the collected di / dt is also 5000 A / μs, without setting the voltage waveform conditioning module 60, due to the existence of parasitic inductance, the collection error is relatively large. So, it may actually be only 3500 A / μs. When the voltage waveform conditioning module 60 is set, since the influence of the parasitic inductance on the collected current is eliminated and the collection error is reduced, the actual di / dt may be closer to 5000 A / μs.

[0062] Among them, the voltage waveform conditioning module 60 may include: a second resistor R2, a third resistor R3, and a second capacitor C2. The second resistor R2 is respectively connected to the first end of the detection resistor R0, the first end of the second capacitor C2, and the positive input terminal of the second operational amplifier OP2. The third resistor R3 is respectively connected to the second end of the detection resistor R0, the second end of the second capacitor C2, and the negative input terminal of the second operational amplifier OP2. By setting the resistance values of the second resistor R2 and the third resistor R3, as well as the capacitance value of the second capacitor C2, filtering processing can be performed on the inductance signal of the parasitic inductance, thereby eliminating the influence of the parasitic inductance. It should be understood that the specific settings of the resistance values of the second resistor R2 and the third resistor R3, as well as the capacitance value of the second capacitor C2, can be set according to the actual situation and are not specifically limited here.

[0063] It should be noted that in combination Figure 5 As shown, this figure shows the action mechanism of the second resistor R2, the third resistor R3, and the second capacitor C2. Among them, L0 represents the parasitic inductance of the detection resistor R0, and the detection resistor R0 is connected in series with the parasitic inductance L0. If the voltage across the series connection of the detection resistor R0 and the parasitic inductance L0 is denoted as Vin, then Vin can satisfy the following relationship 1:

[0064]

[0065] Among them, in the above relationship 1, R s represents the resistance value of the detection resistor R0, i represents the current, t represents the time, L s represents the inductance value of the parasitic inductance L0, and di(t) / dt represents the change rate of the current. After performing Laplace transform on relationship 1, the following relationship 2 can be obtained:

[0066] V in (S) = R s ×i(S) + S×L s ×i(S);

[0067] In the above relational expression 2, S represents a complex variable in Laplace transform.

[0068] Similarly, if the voltage V is connected to the second resistor R2, the third resistor R3 and the second capacitor C2, in The output voltage after filtering is recorded as V out When V out The following relationship 3 can be satisfied:

[0069] V out (S)=R s ×i(S)×(1+S×L s / R s ) / (1+S×C f ×2×R f );

[0070] If you Among them, C f represents the capacitance value of the second capacitor C2, R f represents the resistance of the second resistor R2, and the resistance of the second resistor R2 is the same as the resistance of the third resistor R3; when this relation is substituted into the above relation 3, the following relation 4 can be obtained:

[0071] V out (S)=R s ×i(S);

[0072] It can be known from the above equation 4 that at any sampling frequency, the voltage V in The output voltage V after filtering out It has nothing to do with the parasitic inductance L0 of the detection resistor R0. Since i(S) is the current value that changes with S, V out Therefore, based on this principle, when the voltage waveform conditioning module 60 is composed of the second resistor R2, the third resistor R3 and the second capacitor C2, the influence of the parasitic inductance L0 can be effectively filtered out, so that the collected current is more consistent with the real current, the collection error is reduced, and the authenticity of the collection is improved.

[0073] It should be understood that the structure of the power supply circuit in this embodiment is similar to the above Figure 2 The similarities of the structure of the power supply circuit in the embodiment shown can be seen in the aforementioned Figure 2 The related introduction in the illustrated embodiment will not be repeated any more.

[0074] Figure 6 A schematic diagram showing a current overshoot control method provided by the present application is shown as an example. Figure 6 As shown, the control method may include:

[0075] S601. The second digital-to-analog conversion circuit outputs a fourth reference voltage to the adjustment circuit in response to processing the electrical energy output by the power supply.

[0076] S602. The adjustment circuit outputs a stable first reference voltage to the positive input terminal of the first operational amplifier in response to the fourth reference voltage.

[0077] S603. The first operational amplifier controls the gate voltage of the power transistor in response to the comparison result between the source voltage of the power transistor source and the first reference voltage.

[0078] S604. The power transistor conducts the drain and source in response to the gate voltage being not less than the threshold voltage, so that the power path formed by the power supply, the drain, the source, the detection resistor, and the ground terminal is conducted.

[0079] S605. The voltage regulation module absorbs the electrical energy at the gate of the power transistor in response to the gate voltage being not less than the preset voltage and the power transistor being conductive, so as to control the rising rate of the gate voltage to decrease.

[0080] In this way, when processing the electrical energy output by the power supply, the voltage regulation module can absorb the electrical energy at the gate of the power transistor, so that the gate voltage at the gate of the power transistor will no longer increase or increase slowly as the electrical energy is absorbed, thereby reducing the rising rate of the gate voltage, and the conduction degree of the power transistor remains unchanged or increases slowly. Finally, the current in the power path remains unchanged or increases slowly, avoiding the excessive increase of the current in the power path during transient load pulling, and thus avoiding the current overshoot in the power path.

[0081] Further, the control method may further include:

[0082] The voltage waveform conditioning module filters the voltage across the detection resistor and then inputs voltage signals to the positive input terminal and the negative input terminal of the second operational amplifier respectively.

[0083] The second operational amplifier determines a current signal in response to the voltage signals output from the positive input terminal and the negative input terminal and inputs it to the analog-to-digital converter.

[0084] The analog-to-digital converter generates a corresponding current value in response to the received current signal.

[0085] In this way, the current acquisition can be realized. After being filtered by the voltage waveform conditioning module, the acquired current is closer to the real current, reducing the acquisition error.

[0086] Obviously, those skilled in the art can make various changes and modifications to the embodiments of the present application without departing from the spirit and scope of the embodiments of the present application. Thus, if these modifications and variations of the embodiments of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application is also intended to include these changes and modifications.

Claims

1. A power supply circuit, characterized in that, Comprising: A driving module, a power transistor, and a voltage regulating module; The driving module is respectively connected to the control electrode of the power transistor, the first electrode of the power transistor, and the voltage regulating module. The driving module is configured to: in response to the first electrode voltage of the first electrode of the power transistor and a first reference voltage, control the control voltage of the control electrode of the power transistor; The first electrode of the power transistor is used to be connected to a ground terminal, and the second electrode of the power transistor is used to receive a power supply signal; The voltage regulating module is further connected to the control electrode of the power transistor. The voltage regulating module is configured to: in response to the control voltage being not less than a preset voltage, control the rising rate of the control voltage to decrease.

2. The power supply circuit according to claim 1, wherein The voltage regulating module comprises: a switching unit, a voltage regulating unit, and an RC network. The first end of the switching unit is connected to the control electrode of the power transistor, and the second end of the switching unit is respectively connected to the voltage regulating unit and the RC network; The voltage regulating unit is configured to: provide a second reference voltage to the second end of the switching unit, and the preset voltage is the sum of the second reference voltage and the conduction voltage drop of the switching unit; The switching unit is configured to: in response to the control voltage being not less than the preset voltage, conduct the control electrode of the power transistor and the RC network; The RC network is configured to: in response to the control electrode of the power transistor and the RC network being conducted, control the rising rate of the control voltage to decrease.

3. The power supply circuit according to claim 1 or 2, characterized in that, The power supply circuit further comprises: a detection resistor, a voltage waveform conditioning module, and a current acquisition module. The voltage waveform conditioning module is respectively connected to the first end of the detection resistor, the second end of the detection resistor, and the current acquisition module; the first end of the detection resistor is further connected to the first electrode of the power transistor, and the second end of the detection resistor is connected to the ground terminal; The voltage waveform conditioning module is configured to: after filtering the voltage across the detection resistor, output a voltage signal to the current acquisition module; The current acquisition module is configured to: in response to the voltage signal output by the voltage waveform conditioning module, acquire the current flowing through the detection resistor.

4. The power supply circuit according to claim 3, characterized in that, The voltage waveform conditioning module comprises: a second resistor, a third resistor, and a second capacitor. The second resistor is respectively connected to the first end of the detection resistor, the first end of the second capacitor, and the current acquisition module, and the third resistor is respectively connected to the second end of the detection resistor, the second end of the second capacitor, and the current acquisition module.

5. A power supply circuit, characterized in that, Comprising: A driving module, a power transistor, and a voltage regulating module; The driving module is respectively connected to the control electrode of the power transistor, the first electrode of the power transistor, and the voltage regulating module. The driving module is configured to: in response to the first electrode voltage of the first electrode of the power transistor and a first reference voltage, control the control voltage of the control electrode of the power transistor; The first electrode of the power transistor is used to be connected to a ground terminal, and the second electrode of the power transistor is used to receive a power supply signal; The voltage regulation module includes: a switching unit, a voltage regulation unit, and an RC network. The first end of the switching unit is connected to the control electrode of the power transistor, and the second end of the switching unit is respectively connected to the voltage regulation unit and the RC network; The voltage regulation unit is configured to: provide a second reference voltage to the second end of the switching unit, and the preset voltage is the sum of the second reference voltage and the conduction voltage drop of the switching unit; The switching unit is configured to: in response to the control voltage being not less than the preset voltage, conduct the control electrode of the power transistor to the RC network; The RC network is configured to: in response to the control electrode of the power transistor being conducted to the RC network, control the rising rate of the control voltage to decrease.

6. The power supply circuit according to claim 5, wherein, The power supply circuit further includes: a detection resistor, a voltage waveform conditioning module, and a current acquisition module. The voltage waveform conditioning module is respectively connected to the first end of the detection resistor, the second end of the detection resistor, and the current acquisition module; the first end of the detection resistor is further connected to the first pole of the power transistor, and the second end of the detection resistor is connected to the ground terminal; The voltage waveform conditioning module includes: a second resistor, a third resistor, and a second capacitor. The second resistor is respectively connected to the first end of the detection resistor, the first end of the second capacitor, and the current acquisition module. The third resistor is respectively connected to the second end of the detection resistor, the second end of the second capacitor, and the current acquisition module; The current acquisition module is configured to: in response to the signal processed by the voltage waveform conditioning module, acquire the current flowing through the detection resistor.

7. The power supply circuit according to claim 2, 5 or 6, characterized in that, The preset voltage is: when the power supply circuit is applied to a power supply test scenario, the difference between the control voltage of the power transistor corresponding to the target current to be achieved in the power supply test and the conduction voltage drop of the switching unit.

8. The power supply circuit according to claim 2, 5, 6 or 7, characterized in that The switching unit includes a diode. The positive electrode of the diode is connected to the control electrode of the power transistor, and the negative electrode of the diode is respectively connected to the voltage regulation unit and the RC network.

9. The power supply circuit according to claim 2, 5, 6, 7 or 8, characterized in that The RC network includes: a first resistor and a first capacitor. The first resistor and the first capacitor are connected in parallel between the second end of the switching unit and the ground terminal.

10. The power supply circuit according to claim 2, 5, 6, 7, 8 or 9, characterized in that, The voltage regulation unit includes: a first digital-to-analog conversion circuit and a linear voltage regulator. The linear voltage regulator is connected between the first digital-to-analog conversion circuit and the second end of the switching unit; The first digital-to-analog conversion circuit is configured to: output a third reference voltage to the linear voltage regulator; The linear voltage regulator is configured to: in response to the third reference voltage, provide the second reference voltage to the second end of the switching unit.

11. A control method for current overshoot, characterized in that Implemented by using the power supply circuit according to any one of claims 1-10, the control method includes: The driving module controls the control voltage of the control electrode of the power transistor in response to the first pole voltage of the first pole of the power transistor and the first reference voltage; The voltage regulation module controls the rising rate of the control voltage to decrease in response to the control voltage being not less than the preset voltage.

12. The control method according to claim 11, wherein Further includes: The voltage waveform conditioning module filters the voltage across the detection resistor and outputs a voltage signal to the current acquisition module; The current acquisition module acquires the current flowing through the detection resistor in response to the voltage signal output by the voltage waveform conditioning module.

13. The control method according to claim 11 or 12, characterized in that The preset voltage is: when the power supply circuit is applied to a power supply test scenario, and the voltage regulation module includes a switch unit, a voltage regulation unit, and an RC network, the first end of the switch unit is connected to the control electrode of the power transistor, and the second end of the switch unit is respectively connected to the voltage regulation unit and the RC network, the difference between the control voltage of the power transistor corresponding to the target current to be achieved in the power supply test and the conduction voltage drop of the switch unit.

14. An electronic device, characterized in that, Comprising: The power supply circuit and the circuit board according to any one of claims 1-10, wherein the power supply circuit is disposed on the circuit board and electrically connected to the circuit board.

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