Power circuit and control method applicable thereto

Abstract

The present application relates to a power circuit and a control method applicable thereto. The power circuit includes: a switch assembly, which includes a control end, a first current conduction end and a second current conduction end; a switch drive chip, which includes a desaturation detection circuit, wherein the desaturation detection circuit includes a comparator, a non-inverting input end of which is electrically connected to a current source and the first current conduction end, and an inverting input end of which receives a reference voltage; a switch drive circuit, which outputs a first control signal on the basis of a comparator output signal that is output by the comparator, so as to control the switch assembly; a clamping circuit, which clamps the voltage crossing the non-inverting input end when the switch assembly is turned on; and a capacitor, which is electrically connected to the non-inverting input end and a grounding end, wherein the voltage value of the reference voltage is regulated on the basis of the capacitance value of the capacitor and a switch specification of the switch assembly, and when the capacitor voltage of the capacitor is greater than the reference voltage, the switch drive circuit controls the switch assembly to turn off.

Description

Power circuit and control method thereof TECHNICAL FIELD

[0001] The present application belongs to the technical field of power circuits, and particularly relates to a power circuit and control method thereof, which can optimize the protection of a switching component. BACKGROUND

[0002] In general power circuits, such as those applied to electric vehicle drives, at least one switching component is provided, which may, for example, be any power semiconductor element, such as an insulated gate bipolar transistor (IGBT), a silicon carbide power element (SiC-MOSFET), a silicon power element (Si-MOSFET), and / or a gallium nitride power element (GaN FET), to switch voltage and / or current by switching of the switching component.

[0003] However, different switching components have different switching specifications and characteristics. For example, when the switching component is an insulated gate bipolar transistor or a silicon carbide, the current protection response time of the insulated gate bipolar transistor and the silicon carbide is very different, i.e., the current protection response time of the insulated gate bipolar transistor is about 10 us, and the current protection response time of the silicon carbide is about 2 us. Therefore, the same protection circuit cannot simultaneously meet the requirements of both, for example, when the protection circuit of the silicon carbide is applied to protect the insulated gate bipolar transistor, the slower current protection response time of the insulated gate bipolar transistor may cause the protection circuit to be easily disturbed and have the risk of protection malfunction. Therefore, the versatility of the conventional power circuit is poor.

[0004] Therefore, how to develop a power circuit and control method thereof that can protect switching components with different switching specifications and characteristics is a pressing issue in the field.

[0005] SUMMARY

[0006] The present application is a power circuit and control method thereof, which can meet the current protection response time of switching components with different characteristics to protect the power circuit, thereby improving the versatility of the power circuit.

[0007] To achieve the above object, one embodiment of the present application provides a power circuit, comprising: at least one switching component, comprising a control terminal, a first current conducting terminal and a second current conducting terminal, wherein the at least one switching component comprises a first switching component; a switching driver chip for controlling operation of the at least one switching component, and comprising: a desaturation detection circuit, comprising a comparator, a non-inverting input terminal of the comparator being electrically connected to a first current source and each first current conducting terminal, an inverting input terminal of the comparator being electrically connected to an adjustable voltage source for receiving a reference voltage provided by the adjustable voltage source; and a first switching driving circuit, electrically connected to an output terminal of the comparator and the control terminal of the first switching component, the first switching driving circuit being configured to output a first control signal to the control terminal according to a comparator output signal output by the output terminal of the comparator, so as to control operation of the first switching component; and a clamping circuit, electrically connected between the non-inverting input terminal and each first current conducting terminal, for clamping a voltage on the non-inverting input terminal when the at least one switching component is turned on; and a capacitor, electrically connected between the non-inverting input terminal and a ground terminal, and having a capacitor voltage; wherein a voltage value of the reference voltage is regulated according to a capacitor value of the capacitor and a switching specification of the at least one switching component, and when the capacitor voltage is greater than the reference voltage, the first switching driving circuit controls the first switching component to be turned off.

[0008] To achieve the above object, another embodiment of the present application provides a control method applied to a power circuit, the power circuit comprising at least one switching component, a switching driver chip, a clamping circuit and a capacitor, wherein each switching component comprises a control terminal, a first current conducting terminal and a second current conducting terminal, wherein the at least one switching component comprises a first switching component; the switching driver chip is configured to control operation of the at least one switching component, and comprises a desaturation detection circuit and a first switching driving circuit, the desaturation detection circuit comprising a comparator, a non-inverting input terminal of the comparator being electrically connected to a first current source and each first current conducting terminal, an inverting input terminal of the comparator being electrically connected to an adjustable voltage source for receiving a reference voltage provided by the adjustable voltage source, the first switching driving circuit being electrically connected to an output terminal of the comparator and the control terminal of the corresponding switching component, the first switching driving circuit being configured to output a first control signal to the control terminal according to a comparator output signal output by the output terminal of the comparator, so as to control operation of the first switching component, the clamping circuit being electrically connected between the non-inverting input terminal and each first current conducting terminal, for clamping a voltage on the non-inverting input terminal when the at least one switching component is turned on; the capacitor being electrically connected between the non-inverting input terminal and a ground terminal, and having a capacitor voltage, the control method comprising: (S1) regulating a voltage value of the reference voltage according to a capacitor value of the capacitor and a switching specification of the first switching component; and (S2) when the capacitor voltage is greater than the reference voltage, the first switching driving circuit outputs the first control signal according to the comparator output signal, so as to control the first switching component to be turned off. BRIEF DESCRIPTION OF DRAWINGS

[0009] Fig. 1 is a schematic diagram of a power circuit according to a first preferred embodiment of the present application;

[0010] Fig. 2 is a schematic diagram of a power circuit according to a second preferred embodiment of the present application;

[0011] Fig. 3 is a schematic diagram of a power circuit according to a third preferred embodiment of the present application;

[0012] Figs. 4A, 4B, 4C and 4D are waveform diagrams of a first control signal received by a control terminal of a first switching component and a second control signal received by a control terminal of a second switching component when the power circuit shown in Fig. 3 is in different modes, respectively;

[0013] Fig. 5 is a flow chart of a control method applied to the power circuit shown in Fig. 1; and

[0014] Fig. 6 is a flow chart of a control method applied to the power circuit shown in Fig. 3.

[0015] 1, 1a: power circuit 3: switching drive chip 4: clamping circuit Cblk: capacitor 2a: first switching component T1, T4: control terminal T2, T5: first current conducting terminal T3, T6: second current conducting terminal G: ground terminal 30: desaturation detection circuit CP: comparator CS1: first current source Uref: adjustable voltage source VDD: voltage source 31a: first switching drive circuit Vd: comparator output signal R1: first resistor D1: first diode 5, 5a: control loop Fault: first input terminal Fault_out: first output terminal Gate_IN: second input terminal PWM_IN: second output terminal 310, 312: logic circuit 311, 313: switching circuit Q1, Q3: first switch Q2, Q4: second switch CS2: second current source R2: second resistor D2: second diode Z: snubber diode 2b: second switching component 31b: second switching drive circuit Gate_IN1: third input terminal PWM_IN1: third output terminal CS3: third current source VDD1: first voltage source VDD2: second voltage source S1-S2, S10-S20: steps of the control method DETAILED DESCRIPTION

[0016] Some typical embodiments embodying the features and advantages of the present application are described in detail in the following description. It should be appreciated that the present application can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these described embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the application to those skilled in the art.

[0017] Referring to FIG. 1, a schematic diagram of a power circuit according to a first embodiment of the present application is shown. The power circuit 1 of the present embodiment can be applied in, for example, an electric vehicle drive, and includes at least one switching element, a switching driver chip 3, a clamp circuit 4, and a capacitor Cblk. The at least one switching element, such as the first switching element 2a shown in FIG. 1, can be, but is not limited to, any power semiconductor element, such as an insulated gate bipolar transistor, a silicon carbide power element, a silicon power element, and / or a gallium nitride power element, and includes a control terminal T1, a first current conduction terminal T2, and a second current conduction terminal T3.

[0018] The switching driver chip 3 is electrically connected to the control terminal T1 of each switching element, such as the control terminal T1 of the first switching element 2a, for controlling the operation of the first switching element 2a, and includes a desaturation detection circuit 30 and at least one switching drive circuit. The desaturation detection circuit 30 is electrically connected to the first current conduction terminal T2 of the first switching element 2a and each switching drive circuit for providing a comparator output signal Vd to each switching drive circuit. The desaturation detection circuit 30 includes a comparator CP having a non-inverting input electrically connected to a first current source CS1 and the first current conduction terminal T2, and an inverting input electrically connected to an adjustable voltage source Uref for receiving a reference voltage provided by the adjustable voltage source Uref, wherein the voltage value of the reference voltage is regulated according to the capacitance value of the capacitor Cblk and the switching specification of the first switching element 2a. In some embodiments, the first current source CS1 is also electrically connected to a voltage source VDD.

[0019] The at least one switching drive circuit, such as the first switching drive circuit 31a shown in FIG. 1, is electrically connected to the output of the comparator CP and the control terminal T1 of the first switching element 2a. The first switching drive circuit 31a is configured to output a first control signal to the control terminal T1 for controlling the operation of the corresponding first switching element 2a, wherein the voltage level of the first control signal is also adjusted according to whether the comparator output signal Vd output by the output of the comparator CP is a high-level voltage or a low-level voltage.

[0020] The clamp circuit 4 has a first terminal electrically connected to the non-inverting input of the comparator CP, and a second terminal electrically connected to the first current conduction terminal T2 of the first switching element 2a. The clamp circuit 4 is configured to clamp the voltage at the non-inverting input of the comparator CP when the first switching element 2a is turned on. The capacitor Cblk has a first terminal electrically connected to the non-inverting input of the comparator CP and the first terminal of the clamp circuit 4, and a second terminal electrically connected to a ground terminal G, and has a capacitor voltage.

[0021] When the first switch component 2a is abnormal and short-circuited, the capacitor voltage of the capacitor Cblk is increased and reflected on the non-inverted input terminal of the comparator CP, so that the voltage of the non-inverted input terminal of the comparator CP is greater than the reference voltage provided by the adjustable voltage source Uref. At this time, the output signal Vd of the comparator is a high voltage, and the first switch driving circuit 31a outputs the corresponding first control signal to the control terminal T1 of the first switch component 2a to control the corresponding first switch component 2a to be disconnected to protect the first switch component 2a.

[0022] In the present application, the voltage value of the reference voltage provided by the adjustable voltage source Uref is freely set according to the capacitance value of the capacitor Cblk and the switch specification of the first switch component 2a. Therefore, when the first switch component 2a is composed of an insulated gate bipolar transistor, the voltage value of the reference voltage of the adjustable voltage source Uref is increased, so that the current protection response time of the first switch component 2a is within 10us. Conversely, when the first switch component 2a is composed of silicon carbide, the voltage value of the reference voltage of the adjustable voltage source Uref is decreased, so that the current protection response time of the first switch component 2a is within 2us. Therefore, the power circuit 1 of the present application can satisfy the current protection response time of the first switch component 2a regardless of the switch specification of the first switch component 2a, so that the versatility of the power circuit 1 is large.

[0023] In some embodiments, the reference voltage of the adjustable voltage source Uref can be generated inside the switch driving chip 3 or an external variable voltage can be connected to the pin of the switch driving chip 3. In addition, the clamping circuit 4 includes a first resistor R1 and a first diode D1. The first end of the first resistor R1 is electrically connected to the non-inverted input terminal of the comparator CP, and the second end of the first resistor R1 is electrically connected to the anode end of the first diode D1. The cathode end of the first diode D1 is electrically connected to the first current conduction terminal T2 of the first switch component 2a. In other embodiments, the capacitance value of the capacitor Cblk can be 1000pF to improve the anti-interference ability of the power circuit 1, but is not limited thereto. The capacitance value of the capacitor Cblk is adjusted according to the characteristics of the first switch component 2a, and by increasing the capacitance value of the capacitor Cblk, the anti-interference tolerance can be improved, and the protection time requirement can also be met.

[0024] In some embodiments, the power circuit 1 further comprises a control circuit 5, a first input of the control circuit 5 is electrically connected to the output of the comparator CP to receive the comparator output signal Vd, a first output of the control circuit 5 outputs an alarm signal according to the comparator output signal Vd received by the first input, a second input of the control circuit 5 is electrically connected to a micro control unit (not shown) to receive a control signal outputted by the micro control unit, and the control circuit 5 is logically controlled with reference to the second input Gate IN, a second output PWM IN of the control circuit 5 is electrically connected to the first switch driving circuit 31a to provide a pulse width modulation signal according to the logical control of the control circuit 5 at the second input Gate IN, so as to control the control terminal T1 of the corresponding first switch component 2a.

[0025] In some embodiments, the first switch driving circuit 31a comprises a logic circuit 310 and a switch switching circuit 311, a first input of the logic circuit 310 is electrically connected to the output of the comparator CP to receive the comparator output signal Vd, a second input of the logic circuit 310 is electrically connected to the second output PWM IN of the control circuit 5 to receive the pulse width modulation signal, and the logic circuit 310 outputs a first switching signal to the switch switching circuit 311 at the output of the logic circuit 310 according to the pulse width modulation signal and the comparator output signal Vd. The switch switching circuit 311 comprises a first switch Q1 and a second switch Q2. A control terminal of the first switch Q1 is electrically connected to the output of the logic circuit 310, a first current conducting terminal of the first switch Q1 is electrically connected to a first voltage source VDD1, and the first voltage source VDD1 is connected to the voltage source VDD. A control terminal of the second switch Q2 is electrically connected to the output of the logic circuit 310, a first current conducting terminal of the second switch Q2 is electrically connected to a second current conducting terminal of the first switch Q1 and the control terminal T1 of the corresponding first switch component 2a, and the first control signal outputted by the first switch driving circuit 31a is transmitted to the first switch component 2a from the first current conducting terminal of the second switch Q2 and the second current conducting terminal of the first switch Q1, and the first current conducting terminal of the second switch Q2 is electrically connected to the ground terminal G. When the first switch component 2a is short-circuited due to abnormality, so that the comparator output signal Vd is a high voltage, the first switching signal outputted by the logic circuit 310 controls the first switch Q1 to be turned off and the second switch Q2 to be turned on, thereby controlling the corresponding first switch component 2a to be turned off to protect the first switch component 2a.

[0026] In some embodiments, the power circuit 1 further comprises a second current source CS2 electrically connected between the first current conducting end of the first switch Ql of the first switch driving circuit 31a and the first end of the capacitor Cblk, and is composed of a second resistor R2. The second current source CS2 is used to generate an additional charging current to charge the capacitor Cblk, so that the capacitor Cblk can still meet the current protection response time of the first switch assembly 2a in the case of increasing capacitance value.

[0027] Referring to FIG. 2, it is a structural schematic diagram of a power circuit of a second preferred embodiment of the present application. In some embodiments, as shown in FIG. 2, the power circuit 1 further comprises a first voltage protection circuit composed of a second diode D2, wherein the cathode end of the second diode D2 is electrically connected to the voltage source VDD, and the anode end of the second diode D2 is electrically connected between the first end of the clamping circuit 4 and the non-inverting input end of the comparator CP. The first voltage protection circuit can provide a conduction path in the presence of abnormal transient high voltage (ELECTROSTATIC DISCHARGE, ESD), and further illustrates that when the abnormal transient high voltage appears and the voltage on the anode end of the second diode D2 is greater than the voltage of the voltage source VDD, the second diode D2 is turned on, so that the transient energy flows into the line of the voltage source VDD and is absorbed by the capacitor on the path, thereby achieving the function of overvoltage protection.

[0028] In other embodiments, the power circuit 1 further comprises a second voltage protection circuit composed of a zener diode Z, wherein the cathode end of the zener diode Z is electrically connected between the first end of the clamping circuit 4 and the non-inverting input end of the comparator CP, and the anode end of the zener diode Z is electrically connected to the ground end G. The second voltage protection circuit can provide a conduction path in the presence of abnormal transient high voltage, and further illustrates that when the abnormal transient high voltage appears and the voltage of the cathode end of the zener diode Z is greater than the breakdown voltage of the zener diode Z, the zener diode Z is turned on, so that the transient energy flows into the ground end G through the zener diode Z without flowing into the internal of the switch driving wafer 3, thereby achieving the function of overvoltage protection by changing the noise path. The power circuit 1 can comprise one of the first voltage protection circuit and the second voltage protection circuit, or both.

[0029] Referring to FIG. 3, it is a structural schematic diagram of the power circuit of the third preferred embodiment. The partial circuit structure of the power circuit 1a of the present embodiment is similar to that of the power circuit 1 shown in FIG. 2, and the same symbols are used to represent the similar circuit structures, and will not be described again. In the present embodiment, the power circuit 1a comprises a second switching component 2b in addition to the first switching component 2a. The second switching component 2b comprises a control terminal T4, a first current conduction terminal T5, and a second current conduction terminal T6. In some embodiments, the second switching component 2b can be composed of any power semiconductor element among an insulated gate bipolar transistor, a silicon carbide power element, a silicon power element, and / or a gallium nitride power element, and the first switching component 2a and the second switching component 2b are also composed of different types of power semiconductor elements, for example, the first switching component 2a can be composed of silicon carbide, and the second switching component 2b can be composed of an insulated gate bipolar transistor.

[0030] In addition, the switch driving chip 3 comprises a second switch driving circuit 31b in addition to the first switch driving circuit 31a. The second switch driving circuit 31b is electrically connected to the output terminal of the comparator CP and the control terminal T4 of the second switching component 2b. The second switch driving circuit 31b is used to output a second control signal to the control terminal T4 to control the operation of the second switching component 2b, wherein the voltage level of the second control signal is also adjusted according to whether the comparator output signal Vd output by the output terminal of the comparator CP is a high level voltage or a low level voltage.

[0031] In addition, the control loop 5a further comprises a third input terminal Gate IN1 and a third output terminal PWM IN1. The third input terminal Gate IN1 is electrically connected to the micro control unit to receive the control signal output by the micro control unit, and the control loop 5a performs logical control with reference to the third input terminal Gate IN1. The third output terminal PWM IN1 is electrically connected to the second switch driving circuit 31b to provide another pulse width modulation signal according to the logical control of the control loop 5a at the third input terminal Gate IN1 to control the control terminal T4 of the second switching component 2b.

[0032] In some embodiments, the second switch driving circuit 31b comprises a logic circuit 312 and a switch switching circuit 313. The first input terminal of the logic circuit 312 is electrically connected to the output terminal of the comparator CP to receive the comparator output signal Vd, and the second input terminal of the logic circuit 312 is electrically connected to the third output terminal PWM_IN1 of the control loop 5a to receive the pulse width modulation signal. The logic circuit 310 outputs the second switching signal to the switch switching circuit 313 at the output terminal of the logic circuit 310 according to the pulse width modulation signal outputted by the third output terminal PWM_IN1 and the comparator output signal Vd. The switch switching circuit 313 comprises a first switch Q3 and a second switch Q4. The control terminal of the first switch Q3 is electrically connected to the output terminal of the logic circuit 312, and the first current conducting terminal of the first switch Q3 is electrically connected to the second voltage source VDD2 connected to the voltage source VDD. The control terminal of the second switch Q4 is electrically connected to the output terminal of the logic circuit 312, the first current conducting terminal of the second switch Q4 is electrically connected to the second current conducting terminal of the first switch Q3 and the control terminal T1 of the second switch component 2b, and the second control signal outputted by the second switch driving circuit 31b is transmitted to the second switch component 2b from the first current conducting terminal of the second switch Q4 and the second current conducting terminal of the first switch Q3. In addition, the first current conducting terminal of the second switch Q2 is electrically connected to the ground terminal. When the second switch component 2b is short-circuited abnormally, so that the comparator output signal Vd is a high voltage, the fourth control signal outputted by the logic circuit 312 controls the third switch Q3 to be off and the fourth switch Q4 to be on, thereby controlling the second switch component 2b to be off to protect the second switch component 2b.

[0033] In addition, in some embodiments, the power circuit 1a further comprises a third current source CS3 electrically connected between the first current conducting terminal of the first switch Q3 of the second switch driving circuit 31b and the first terminal of the capacitor Cblk, and composed of the third resistor R3. The third current source CS3 is used to generate an additional charging current to charge the capacitor Cblk, so that the capacitor Cblk can still meet the current protection response time of the first switch component 2a in the case of increasing the capacitance value.

[0034] Further, in some embodiments, the voltage source VDD voltage is regulated to provide different voltages to the first voltage source VDD1 and the second voltage source VDD2 according to the Vgs specifications of the first switching component 2a and the second switching component 2b. For example, when the Vgs specifications of the first switching component 2a and the second switching component 2b are different, the voltage source VDD voltage is regulated to provide different voltages to the first voltage source VDD1 and the second voltage source VDD2. For example, if the first switching component 2a selects an IGBT with a Vgs of 15V and the second switching component 2b selects a GaN with a Vgs of 8V, the VDD voltage is regulated to provide a 15V voltage source to the first voltage source VDD1 and an 8V voltage source to the second voltage source VDD2.

[0035] In the foregoing embodiments, the voltage source VDD, the first voltage source VDD1 and the second voltage source VDD2 can also be different voltage sources provided by a system in which the power circuit is located via a peripheral circuit (not shown in the figures). For example, if the power circuit is disposed on a motherboard, the motherboard provides different voltage sources.

[0036] Referring to FIGS. 4A, 4B, 4C and 4D, FIGS. 4A to 4D are waveform diagrams of the first control signal received by the control terminal of the first switching component and the second control signal received by the control terminal of the second switching component of the power circuit shown in FIG. 3 in different modes. First, if the first switching component 2a and the second switching component 2b operate in the first mode, i.e., as shown in FIG. 4A, when the first switching component 2a and the second switching component 2b are simultaneously turned on and off, the reference voltage provided by the voltage source Uref can be adjusted to a first voltage level, e.g., 14V, when the first switching component 2a and the second switching component 2b start to turn on, where 14V is the voltage corresponding to the current protection response time of the second switching component 2b composed of an insulated gate bipolar transistor. When the first switching component 2a and the second switching component 2b are fully turned on, the reference voltage provided by the voltage source Uref can be adjusted to a second voltage level, e.g., 6V, where 6V is the voltage corresponding to the current protection response time of the first switching component 2a composed of silicon carbide. When the first switching component 2a and the second switching component 2b start to turn off from being fully turned on, the reference voltage provided by the voltage source Uref can be adjusted to the first voltage level.

[0037] If the first switch component 2a and the second switch component 2b operate in the second mode, as shown in FIG. 4B, the first switch component 2a and the second switch component 2b are simultaneously turned on, but the first switch component 2a starts to turn off later than the second switch component 2b, the reference voltage provided by the adjustable voltage source Uref is regulated to the first voltage level when the first switch component 2a and the second switch component 2b start to turn on. When the first switch component 2a and the second switch component 2b are fully turned on, the reference voltage provided by the adjustable voltage source Uref is regulated to the second voltage level. When the second switch component 2b starts to turn off from fully turned on, the reference voltage provided by the adjustable voltage source Uref is regulated to the second voltage level.

[0038] If the first switch component 2a and the second switch component 2b operate in the third mode, as shown in FIG. 4C, the first switch component 2a starts to turn on earlier than the second switch component 2b, and the first switch component 2a starts to turn off later than the second switch component 2b, the reference voltage provided by the adjustable voltage source Uref is regulated to the second voltage level when the first switch component 2a starts to turn on. When the first switch component 2a and the second switch component 2b are fully turned on, the reference voltage provided by the adjustable voltage source Uref is regulated to the second voltage level. When the second switch component 2b starts to turn off from fully turned on, the reference voltage provided by the adjustable voltage source Uref is regulated to the second voltage level.

[0039] If the first switch component 2a and the second switch component 2b operate in the fourth mode, as shown in FIG. 4D, the second switch component 2b starts to turn on earlier than the first switch component 2a, and the first switch component 2a starts to turn off later than the second switch component 2b, the reference voltage provided by the adjustable voltage source Uref is regulated to the first voltage level when the second switch component 2b starts to turn on. When the first switch component 2a and the second switch component 2b are fully turned on, the reference voltage provided by the adjustable voltage source Uref is regulated to the second voltage level. When the second switch component 2b starts to turn off from fully turned on, the reference voltage provided by the adjustable voltage source Uref is regulated to the second voltage level.

[0040] Please refer to FIG. 5, which is a flow chart of the control method applied to the power circuit shown in FIG. 1. The control method of the present embodiment can be applied to the power circuit 1 shown in FIG. 1, and includes the following steps.

[0041] Step (S1), the voltage value of the reference voltage is regulated according to the capacitance value of the capacitor Cblk and the switch specification of the first switch component 2a.

[0042] Step (S2), when the capacitor voltage of the capacitor Cblk is greater than the reference voltage, the first switch driving circuit 31a outputs a first control signal according to the comparator output signal to control the first switch component 2a to be turned off.

[0043] Please refer to FIG. 6, which is a flow chart of the control method applied to the power circuit shown in FIG. 3. The control method of the present embodiment can be applied to the power circuit 1a shown in FIG. 3, and includes the following steps.

[0044] Step (S10), the voltage value of the reference voltage is adjusted according to the capacitance value of the capacitor Cblk, the switch specifications of the first switch component 2a and the second switch component 2b.

[0045] Step (S20), when the capacitor voltage of the capacitor Cblk is greater than the reference voltage, the first switch driving circuit 31a outputs a first control signal according to the comparator output signal to control the first switch component 2a to be turned off, and the second switch driving circuit 31b outputs a second control signal according to the comparator output signal to control the second switch component 2b to be turned off.

[0046] In some embodiments, if the first switch component 2a and the second switch component 2b are turned on and turned off at the same time, in step (S1), the reference voltage provided by the voltage source Uref can be adjusted to the first voltage level when the first switch component 2a and the second switch component 2b start to be turned on, and when the first switch component 2a and the second switch component 2b are fully turned on, the reference voltage provided by the voltage source Uref can be adjusted to the second voltage level, and when the first switch component 2a and the second switch component 2b start to be turned off from being fully turned on, the reference voltage provided by the voltage source Uref can be adjusted to the first voltage level.

[0047] In some embodiments, if the first switch component 2a and the second switch component 2b are turned on at the same time, and the first switch component 2a starts to be turned off later than the second switch component 2b, in step (S1), the reference voltage provided by the voltage source Uref can be adjusted to the first voltage level when the first switch component 2a and the second switch component 2b start to be turned on, and when the first switch component 2a and the second switch component 2b are fully turned on, the reference voltage provided by the voltage source Uref can be adjusted to the second voltage level, and when the second switch component 2b starts to be turned off from being fully turned on, the reference voltage provided by the voltage source Uref can be adjusted to the second voltage level.

[0048] In some embodiments, if the first switch component 2a starts to turn on earlier than the second switch component 2b, and the first switch component 2a starts to turn off later than the second switch component 2b, in step (S1), the reference voltage provided by the adjustable voltage source Uref is adjusted to the second voltage level when the first switch component 2a starts to turn on, and the reference voltage provided by the adjustable voltage source Uref is adjusted to the second voltage level when the first switch component 2a and the second switch component 2b are fully turned on, and the reference voltage provided by the adjustable voltage source Uref is adjusted to the second voltage level when the second switch component 2b starts to turn off from being fully turned on.

[0049] In some embodiments, if the second switch component 2b starts to turn on earlier than the first switch component 2a, and the first switch component 2a starts to turn off later than the second switch component 2b, in step (S1), the reference voltage provided by the adjustable voltage source Uref is adjusted to the first voltage level when the second switch component 2b starts to turn on, and the reference voltage provided by the adjustable voltage source Uref is adjusted to the second voltage level when the first switch component 2a and the second switch component 2b are fully turned on, and the reference voltage provided by the adjustable voltage source Uref is adjusted to the second voltage level when the second switch component 2b starts to turn off from being fully turned on.

[0050] In summary, the power circuit and the control method thereof provided in the present application can satisfy the current protection response time of switch components with different characteristics by adjusting the reference voltage provided by the adjustable voltage source, so as to protect switch components with different specifications, and therefore the power circuit provided in the present application has high versatility.

Claims

1. An electric power circuit, characterized by The power circuit comprises: at least one switch component, each of the switch components comprising a control terminal, a first current conducting terminal and a second current conducting terminal, wherein the at least one switch component comprises a first switch component; a switch driving chip for controlling the operation of the at least one switch component, and comprising: a desaturation detection circuit comprising a comparator, a non-inverted input terminal of the comparator being electrically connected to a first current source and each of the first current conducting terminals, an inverted input terminal of the comparator being electrically connected to an adjustable voltage source for receiving a reference voltage provided by the adjustable voltage source; a first switch driving circuit electrically connected to an output terminal of the comparator and the control terminal of the first switch component, the first switch driving circuit being configured to output a first control signal to the control terminal according to a comparator output signal output by the output terminal of the comparator, so as to control the operation of the first switch component; and a clamping circuit electrically connected between the non-inverted input terminal and each of the first current conducting terminals, for clamping the voltage on the non-inverted input terminal when the at least one switch component is turned on; and a capacitor electrically connected between the non-inverted input terminal and a ground terminal, and having a capacitor voltage; wherein the voltage value of the reference voltage is regulated according to the capacitor value of the capacitor and the switch specifications of the at least one switch component, and when the capacitor voltage is greater than the reference voltage, the first switch driving circuit controls the first switch component to be turned off. The reference voltage is generated internally by the switch driving chip or is provided by an external voltage externally connected to a pin of the switch driving chip. The clamping circuit comprises a first resistor and a first diode, a first end of the first resistor being electrically connected to the non-inverted input terminal of the comparator, a second end of the first resistor being electrically connected to an anode terminal of the first diode, and a cathode terminal of the first diode being electrically connected to the first current conducting terminal of the first switch component.

2. The power circuit of claim 1, wherein, The capacitor value of the capacitor is 1000 pF.

3. The power circuit of claim 1, wherein, The power circuit further comprises a second current source electrically connected between the first switch driving circuit and the capacitor, and composed of a second resistor, the second current source being configured to generate an additional charging current to charge the capacitor.

4. The power circuit of claim 1, wherein, The power circuit further comprises a first voltage protection circuit composed of a second diode, a cathode terminal of the second diode being electrically connected to a voltage source, and an anode terminal of the second diode being electrically connected between the clamping circuit and the non-inverted input terminal of the comparator.

5. The power circuit of claim 1, wherein, The power circuit further comprises a second voltage protection circuit composed of a snubber diode, wherein a cathode terminal of the snubber diode is electrically connected between the clamping circuit and the non-inverted input terminal of the comparator, and an anode terminal of the snubber diode is electrically connected to the ground terminal.

6. The power circuit of claim 1, wherein, The switch component further comprises a second switch component, the first switch component and the second switch component being different types of power semiconductor elements.

7. The power circuit of claim 1, wherein, ​ 8. The power circuit of claim 1, wherein, ​ 9. The power circuit of claim 8, wherein, The first switch component and the second switch component have different current protection response times, and the switch driving chip further comprises a second switch driving circuit electrically connected to the output terminal of the comparator and the control terminal of the second switch component, and configured to output a second control signal to the control terminal of the second switch component according to the output signal of the comparator, so as to control the operation of the second switch component.

10. The power circuit of claim 9, wherein, The first switch component and the second switch component are simultaneously turned on and turned off, and the reference voltage is regulated to a first voltage level when the first switch component and the second switch component start to be turned on, wherein the first voltage level is a voltage corresponding to the current protection response time of the second switch component, and the reference voltage is regulated to a second voltage level when the first switch component and the second switch component are fully turned on, wherein the second voltage level is a voltage corresponding to the current protection response time of the first switch component, and the reference voltage is regulated to the first voltage level when the first switch component and the second switch component start to be turned off.

11. The power circuit of claim 9, wherein, The first switch component and the second switch component are simultaneously turned on, and the first switch component starts to be turned off later than the second switch component, and the reference voltage is regulated to a first voltage level when the first switch component and the second switch component start to be turned on, and the reference voltage is regulated to a second voltage level when the first switch component and the second switch component are fully turned on, and the reference voltage is regulated to the second voltage level when the second switch component starts to be turned off.

12. The power circuit of claim 9, wherein, The first switch component starts to be turned on earlier than the second switch component, and the first switch component starts to be turned off later than the second switch component, and the reference voltage is regulated to a second voltage level when the first switch component starts to be turned on, and the reference voltage is regulated to the second voltage level when the first switch component and the second switch component are fully turned on, and the reference voltage is regulated to the second voltage level when the second switch component starts to be turned off.

13. The power circuit of claim 9, wherein, The second switch component starts to be turned on earlier than the first switch component, and the first switch component starts to be turned off later than the second switch component, and the reference voltage is regulated to a first voltage level when the second switch component starts to be turned on, and the reference voltage is regulated to a second voltage level when the first switch component and the second switch component are fully turned on, and the reference voltage is regulated to the second voltage level when the second switch component starts to be turned off.

14. The power circuit of claim 9, wherein, The voltage source supplies a first voltage source and a second voltage source with different voltages according to the Vgs specifications of the first switch component and the second switch component.

15. A control method characterized by, The application is applied to a power circuit, which comprises at least one switching component, a switching driving chip, a clamping circuit and a capacitor. Each of the switching components comprises a control terminal, a first current conducting terminal and a second current conducting terminal. The at least one switching component comprises a first switching component. The switching driving chip is used to control the operation of the at least one switching component and comprises a desaturation detection circuit and a first switching driving circuit. The desaturation detection circuit comprises a comparator. A non-inverted input terminal of the comparator is electrically connected to a first current source and each of the first current conducting terminals. An inverted input terminal of the comparator is electrically connected to an adjustable voltage source to receive a reference voltage provided by the adjustable voltage source. The first switching driving circuit is electrically connected to an output terminal of the comparator and the control terminal of the corresponding switching component. The first switching driving circuit is used to output a first control signal to the control terminal according to a comparator output signal output by the output terminal of the comparator to control the operation of the first switching component. The clamping circuit is electrically connected between the non-inverted input terminal and each of the first current conducting terminals to clamp the voltage on the non-inverted input terminal when the at least one switching component is turned on. The capacitor is electrically connected between the non-inverted input terminal and a ground terminal and has a capacitor voltage. The control method comprises: (S1) adjusting the voltage value of the reference voltage according to the capacitor value of the capacitor and the switching specification of the first switching component; and (S2) when the capacitor voltage is greater than the reference voltage, the first switching driving circuit outputs the first control signal according to the comparator output signal to control the first switching component to be turned off.

16. The control method according to claim 15, characterized by The at least one switching component further comprises a second switching component. The first switching component and the second switching component are different power semiconductor element types. The first switching component and the second switching component have different current protection response times. The switching driving chip further comprises a second switching driving circuit. The second switching driving circuit is electrically connected to the output terminal of the comparator and the control terminal of the second switching component. The second switching driving circuit is used to output a second control signal to the control terminal of the second switching component according to the comparator output signal to control the operation of the second switching component. In the step (S1), the voltage value of the reference voltage is also adjusted according to the switching specification of the second switching component. In the step (S2), when the capacitor voltage is greater than the reference voltage, the second switching driving circuit outputs the second control signal according to the comparator output signal to control the second switching component to be turned off.

17. The control method according to claim 16, characterized by The first switch assembly and the second switch assembly are simultaneously turned on and turned off, and in the step (S1), the reference voltage is regulated to a first level voltage when the first switch assembly and the second switch assembly start to be turned on, wherein the first level voltage is a voltage corresponding to a current protection response time of the second switch assembly, and the reference voltage is regulated to a second level voltage when the first switch assembly and the second switch assembly are completely turned on, wherein the second level voltage is a voltage corresponding to a current protection response time of the first switch assembly, and the reference voltage is regulated to the first level voltage when the first switch assembly and the second switch assembly start to be turned off from being completely turned on.

18. The control method according to claim 16, wherein The first switch assembly and the second switch assembly are simultaneously turned on, and the first switch assembly starts to be turned off later than the second switch assembly, and in the step (S1), the reference voltage is regulated to a first level voltage when the first switch assembly and the second switch assembly start to be turned on, and the reference voltage is regulated to a second level voltage when the first switch assembly and the second switch assembly are completely turned on, and the reference voltage is regulated to the second level voltage when the second switch assembly starts to be turned off from being completely turned on.

19. The control method according to claim 16, wherein The first switch assembly starts to be turned on earlier than the second switch assembly, and the first switch assembly starts to be turned off later than the second switch assembly, and in the step (S1), the reference voltage is regulated to a second level voltage when the first switch assembly starts to be turned on, and the reference voltage is regulated to the second level voltage when the first switch assembly and the second switch assembly are completely turned on, and the reference voltage is regulated to the second level voltage when the second switch assembly starts to be turned off from being completely turned on.

20. The control method according to claim 16, wherein The second switch assembly starts to be turned on earlier than the first switch assembly, and the first switch assembly starts to be turned off later than the second switch assembly, and in the step (S1), the reference voltage is regulated to a first level voltage when the second switch assembly starts to be turned on, and the reference voltage is regulated to a second level voltage when the first switch assembly and the second switch assembly are completely turned on, and the reference voltage is regulated to the second level voltage when the second switch assembly starts to be turned off from being completely turned on.

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