Power circuit and applicable control method thereof

Abstract

The invention relates to a power circuit and an applicable control method thereof, and the power circuit comprises a switch assembly which comprises a control end, a first current conduction end and a second current conduction end; the switch driving chip comprises a desaturation detection circuit which comprises a comparator, the non-reverse input end of the comparator is electrically connected to the current source and the first current conduction end, and the reverse input end of the comparator receives the reference voltage; the switch driving circuit is used for outputting a first control signal to control the switch assembly according to a comparator output signal output by the comparator; the clamping circuit is used for clamping the voltage on the non-reverse input end when the switch assembly is switched on; the capacitor is electrically connected to the non-reverse input end and the grounding end; wherein the voltage value of the reference voltage is regulated according to the capacitance value of the capacitor and the switch specification of the switch assembly, and when the capacitance voltage of the capacitor is greater than the reference voltage, the switch driving circuit controls the switch assembly to be switched off.

Description

Technical Field

[0001] This case pertains to the technical field of power circuits, and in particular to a power circuit that can optimize the protection of switching components and the applicable control method thereof. Background Technology

[0002] In a typical power circuit, such as a power circuit used in an electric vehicle drive, there is at least one switching component. The switching component can be any power semiconductor device, such as an insulated gate bipolar transistor (IGBT), a silicon carbide power device (SiC-MOSFET), a silicon power device (Si-MOSFET), and / or a gallium nitride power device (GaN FET), to switch the voltage and / or current by switching the switching component.

[0003] However, different switching components have different switching specifications and characteristics. For example, when the switching component is made of insulated gate bipolar transistor (IGBT) or silicon carbide (SiC), the current protection response time of IGBT and SiC differs greatly. That is, the current protection response time of IGBT is about 10µs, while that of SiC is about 2µs. Therefore, the same protection circuit cannot meet the requirements of both at the same time. For example, when SiC protection circuit is used to protect IGBT, the slower current protection response time of IGBT may cause the protection circuit to be easily interfered with, resulting in the risk of protection malfunction. Therefore, the versatility of traditional power circuits is not good.

[0004] Therefore, how to develop power circuits that can protect switching components of different switch specifications and characteristics, and the applicable control methods therein, is an urgent issue that needs to be addressed in this field. Summary of the Invention

[0005] This invention relates to a power circuit and its applicable control method. The power circuit can provide protection by meeting the current protection response time of switching components with different characteristics, thereby improving the versatility of the power circuit.

[0006] To achieve the above objectives, one embodiment of this application provides a power circuit comprising: at least one switching component, including a control terminal, a first current conduction terminal, and a second current conduction terminal, wherein the at least one switching component includes a first switching component; a switch driver chip for controlling the operation of the at least one switching component, and including: a desaturation detection circuit, including a comparator, the non-inverting input terminal of the comparator being electrically connected to a first current source and each of the first current conduction terminals, and the inverting input terminal of the comparator being electrically connected to an adjustable voltage source to receive a reference voltage provided by the adjustable voltage source; and a first switch driving circuit electrically connected to the output terminal of the comparator and the control terminal of the first switching component. The first switch driving circuit is used to output a first control signal to the control terminal according to the comparator output signal output by the comparator output terminal, so as to control the operation of the first switch component; and a clamping circuit is electrically connected between the non-inverting input terminal and each first current conduction terminal, used to clamp the voltage on the non-inverting input terminal when at least one switch component is turned on; and a capacitor is electrically connected between the non-inverting input terminal and the ground terminal, and has a capacitor voltage; wherein the voltage value of the reference voltage is adjusted according to the capacitance value of the capacitor and the switching 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 turn off.

[0007] To achieve the above objectives, another embodiment of this application provides a control method applied to a power circuit. The power circuit includes at least one switching component, a switch driver chip, a clamping circuit, and a capacitor. Each switching component includes a control terminal, a first current conduction terminal, and a second current conduction terminal. The at least one switching component includes a first switching component. The switch driver chip controls the operation of the at least one switching component and includes a desaturation detection circuit and a first switch driving circuit. The desaturation detection circuit includes a comparator. The non-inverting input terminal of the comparator is electrically connected to a first current source and each first current conduction terminal. The inverting 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 switch driving circuit is connected to the output terminal of the comparator and the corresponding switch. The control terminal of the component is electrically connected. The first switch driving circuit is used to output a first control signal to the control terminal according to the comparator output signal output by the comparator output terminal, so as to control the operation of the first switch component. The clamping circuit is electrically connected between the non-inverting input terminal and each first current conduction terminal, so as to clamp the voltage on the non-inverting input terminal when at least one switch component is turned on. The capacitor is electrically connected between the non-inverting input terminal and the ground terminal and has a capacitor voltage. The control method includes: (S1) adjusting the voltage value of the reference voltage according to the capacitance value of the capacitor and the switching specifications of the first switch component; and (S2) when the capacitor voltage is greater than the reference voltage, the first switch driving circuit outputs a first control signal according to the comparator output signal, so as to control the first switch component to turn off. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of the power circuit structure of the first preferred embodiment of this case;

[0009] Figure 2 This is a schematic diagram of the power circuit structure of the second preferred embodiment of this case;

[0010] Figure 3 This is a schematic diagram of the power circuit structure of the third preferred embodiment of this case;

[0011] Figure 4A , Figure 4B , Figure 4C and Figure 4D They are respectively Figure 3 The diagram shows the waveforms 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 in different modes of the power circuit shown.

[0012] Figure 5 For application Figure 1 The flowchart of the control method for the power circuit shown; and

[0013] Figure 6 For application Figure 3 The flowchart shows the steps of the control method for the power circuit.

[0014] [Symbol Explanation]

[0015] 1. 1a: Power circuit

[0016] 3: Switch driver chip

[0017] 4: Clamping circuit

[0018] Cblk: Capacitor

[0019] 2a: First switch assembly

[0020] T1, T4: Control terminals

[0021] T2, T5: First current conduction terminals

[0022] T3, T6: Second current conduction terminals

[0023] G: Grounding terminal

[0024] 30: Desaturation detection circuit

[0025] CP: Comparator

[0026] CS1: First current source

[0027] Uref: Adjustable voltage source

[0028] VDD: Voltage source

[0029] 31a: First switch drive circuit

[0030] Vd: Comparator output signal

[0031] R1: First resistor

[0032] D1: First diode

[0033] 5, 5a: Control loop

[0034] Fault: First Input Terminal

[0035] Fault_out: First output terminal

[0036] Gate_IN: Second input terminal

[0037] PWM_IN: Second output terminal

[0038] 310, 312: Logic circuits

[0039] 311, 313: Switching circuit

[0040] Q1, Q3: First switch

[0041] Q2, Q4: Second switches

[0042] CS2: Second current source

[0043] R2: Second resistor

[0044] D2: Second diode

[0045] Z: Jina Diode

[0046] 2b: Second switch assembly

[0047] 31b: Second switch drive circuit

[0048] Gate_IN1: Third input terminal

[0049] PWM_IN1: Third output terminal

[0050] CS3: Third Current Source

[0051] VDD1: First voltage source

[0052] VDD2: Second voltage source

[0053] S1~S2, S10~S20: Steps of the control method Detailed Implementation

[0054] Some typical embodiments that embody the features and advantages of this invention will be described in detail in the following description. It should be understood that this invention can have various variations in different forms, all of which do not depart from the scope of this invention, and the descriptions and illustrations therein are for illustrative purposes only, and are not intended to limit this invention.

[0055] Please see Figure 1 This is a schematic diagram of the power circuit structure of the first preferred embodiment of this invention. The power circuit 1 of this embodiment can be applied, for example, in an electric vehicle drive system, and includes at least one switching component, a switch driver chip 3, a clamping circuit 4, and a capacitor Cblk. At least one switching component, for example... Figure 1 The first switching component 2a shown may be, but is not limited to, any power semiconductor element selected from insulated gate bipolar transistors, silicon carbide power elements, silicon power elements and / or gallium nitride power elements, and includes a control terminal T1, a first current conduction terminal T2 and a second current conduction terminal T3.

[0056] The switch driver chip 3 is electrically connected to the control terminal T1 of each switch component, such as the control terminal T1 of the first switch component 2a, to control the operation of the first switch component 2a, and includes a desaturation detection circuit 30 and at least one switch drive circuit. The desaturation detection circuit 30 is electrically connected to the first current conduction terminal T2 of the first switch component 2a and each switch drive circuit to provide a comparator output signal Vd to each switch drive circuit. The desaturation detection circuit 30 includes a comparator CP. The non-inverting input terminal of the comparator CP is electrically connected to the first current source CS1 and the first current conduction terminal T2. The inverting input terminal of the comparator CP is electrically connected to an adjustable voltage source Uref to receive a reference voltage provided by the adjustable voltage source Uref, wherein the voltage value of the reference voltage is adjusted according to the capacitance value of the capacitor Cblk and the switching specifications of the first switch component 2a. In some embodiments, the first current source CS1 is also electrically connected to the voltage source VDD.

[0057] At least one switch drive circuit, for example Figure 1 The first switch drive circuit 31a shown is electrically connected to the output terminal of the comparator CP and the control terminal T1 of the first switch assembly 2a. The first switch drive circuit 31a is used to output a first control signal to the control terminal T1 to control the operation of the corresponding first switch assembly 2a. The voltage level of the first 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.

[0058] The first terminal of clamping circuit 4 is electrically connected to the non-inverting input terminal of comparator CP, and the second terminal of clamping circuit 4 is electrically connected to the first current conduction terminal T2 of the first switching component 2a. Clamping circuit 4 is used to clamp the voltage on the non-inverting input terminal of comparator CP when the first switching component 2a is turned on. The first terminal of capacitor Cblk is electrically connected to the non-inverting input terminal of comparator CP and the first terminal of clamping circuit 4, and the second terminal of capacitor Cblk is electrically connected to ground terminal G, and capacitor Cblk has a capacitor voltage.

[0059] When the first switching component 2a malfunctions and short-circuits, the capacitor voltage Cblk will increase and be reflected at the non-inverting input terminal of the comparator CP, making the voltage at the non-inverting input terminal of the comparator CP greater than the reference voltage provided by the adjustable voltage source Uref. At this time, the comparator output signal Vd is a high-level voltage. Therefore, the first switch drive circuit 31a outputs the corresponding first control signal to the control terminal T1 of the first switching component 2a to control the corresponding first switching component 2a to disconnect and protect the first switching component 2a.

[0060] In this case, since the reference voltage provided by the adjustable voltage source Uref is freely set according to the capacitance value of capacitor Cblk and the switching specifications of the first switching component 2a, when the first switching component 2a is, for example, composed of an insulated gate bipolar transistor, the reference voltage of the adjustable voltage source Uref increases, so that the current protection response time of the first switching component 2a is within 10µs. Conversely, when the first switching component 2a is, for example, composed of silicon carbide, the reference voltage of the adjustable voltage source Uref decreases, so that the current protection response time of the first switching component 2a is within 2µs. Therefore, the power circuit 1 of this case can meet the current protection response time of the first switching component 2a regardless of the switching specifications of the first switching component 2a, making the power circuit 1 highly versatile.

[0061] In some embodiments, the reference voltage of the adjustable voltage source Uref can be generated internally by the switch driver chip 3 or by connecting a variable external voltage to the pin of the switch driver chip 3. Additionally, 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-inverting input terminal of the comparator CP, and the second end of the first resistor R1 is electrically connected to the anode terminal of the first diode D1. The cathode terminal of the first diode D1 is electrically connected to the first current conduction terminal T2 of the first switching component 2a. In other embodiments, the capacitance value of capacitor Cblk can be 1000pF to improve the anti-interference capability of the power circuit 1, but this is not a limitation. The capacitance value of capacitor Cblk is adjusted according to the characteristics of the first switching component 2a. By increasing the capacitance value of capacitor Cblk, the anti-interference tolerance can be improved, and the protection time requirement can also be met.

[0062] In some embodiments, the power circuit 1 further includes a control loop 5. The first input terminal Fault of the control loop 5 is electrically connected to the output terminal of the comparator CP to receive the comparator output signal Vd. The first output terminal Fault_out of the control loop 5 outputs an alarm signal based on the comparator output signal Vd received at the first input terminal. The second input terminal Gate_IN of the control loop 5 is electrically connected to the microcontroller unit (not shown) to receive the control signal output by the microcontroller unit. The control loop 5 performs logic control with reference to the second input terminal Gate_IN. The second output terminal PWM_IN of the control loop 5 is electrically connected to the first switch drive circuit 31a to provide a pulse width modulation signal according to the logic control of the control loop 5 at the second input terminal Gate_IN to control the control terminal T1 of the first switch assembly 2a.

[0063] In some embodiments, the first switch driving circuit 31a includes a logic circuit 310 and a switch switching circuit 311. The first input terminal of the logic circuit 310 is electrically connected to the output terminal of the comparator CP to receive the comparator output signal Vd. The second input terminal of the logic circuit 310 is electrically connected to the second output terminal PWM_IN of the control loop 5 to receive the pulse width modulation signal. Based on the pulse width modulation signal and the comparator output signal Vd, the logic circuit 310 outputs a first switching signal to the switch switching circuit 311. The switch switching circuit 311 includes a first switch Q1 and a second switch Q2. The control terminal of the first switch Q1 is electrically connected to the output terminal of the logic circuit 310, and the first current conduction terminal of the first switch Q1 is electrically connected to the first voltage source VDD1. The first voltage source VDD1 is connected to the voltage source VDD. The control terminal of the second switch Q2 is electrically connected to the output terminal of the logic circuit 310. The first current conduction terminal of the second switch Q2 is electrically connected to the second current conduction terminal of the first switch Q1 and the corresponding control terminal T1 of the first switch assembly 2a. The first control signal output by the first switch drive circuit 31a is transmitted to the first switch assembly 2a through the first current conduction terminal of the second switch Q2 and the second current conduction terminal of the first switch Q1. The first current conduction terminal of the second switch Q2 is electrically connected to the ground terminal G. When the first switch assembly 2a malfunctions and short-circuits, causing the comparator output signal Vd to be a high-level voltage, the first switching signal output by the logic circuit 310 controls the first switch Q1 to turn off and the second switch Q2 to turn on, thereby controlling the corresponding first switch assembly 2a to turn off to protect the first switch assembly 2a.

[0064] In some embodiments, the power circuit 1 further includes a second current source CS2, which is electrically connected between the first current conduction terminal of the first switch Q1 of the first switch drive circuit 31a and the first terminal 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 even when the capacitance value is increased.

[0065] Please see Figure 2 This is a schematic diagram of the power circuit structure of the second preferred embodiment of this case. In some embodiments, such as... Figure 2 As shown, the power circuit 1 also includes a first voltage protection circuit, which is composed of a second diode D2. The cathode of the second diode D2 is connected to the voltage source VDD, and the anode of the second diode D2 is connected between the first terminal of the clamping circuit 4 and the non-inverting input terminal of the comparator CP. The first voltage protection circuit can provide a conduction path in the event of an abnormal sudden transient high voltage (ELECTROSTATIC DISCHARGE, ESD). To further explain, when an abnormal sudden transient high voltage occurs and the voltage on the anode of the second diode D2 is greater than the voltage of the voltage source VDD, the second diode D2 conducts, allowing the transient energy to flow into the line of the voltage source VDD and be absorbed by the capacitor in its path, thereby achieving the function of overvoltage protection.

[0066] In other embodiments, the power circuit 1 further includes a second voltage protection circuit, which is composed of a Zener diode Z. The cathode of the Zener diode Z is electrically connected between the first terminal of the clamping circuit 4 and the non-inverting input terminal of the comparator CP, and the anode of the Zener diode Z is electrically connected to the ground terminal G. The second voltage protection circuit can provide a conduction path under abnormal sudden transient high voltage. More specifically, when an abnormal sudden transient high voltage occurs and the voltage at the cathode of the Zener diode Z exceeds the breakdown voltage of the Zener diode Z, the Zener diode Z conducts, allowing transient energy to flow through the Zener diode Z into the ground terminal G instead of into the internal circuit of the switch driver chip 3. This achieves overvoltage protection by changing the noise path. The power circuit 1 may include one or both of the first and second voltage protection circuits.

[0067] Please see Figure 3 This is a schematic diagram of the power circuit structure of the third preferred embodiment of this case. Part of the circuit structure of the power circuit 1a in this embodiment is similar to... Figure 2The circuit structures of the power circuits 1 shown are similar, so they are represented by the same symbols and will not be described again. In this embodiment, in addition to the first switching component 2a, the power circuit 1a also includes a second switching component 2b. The second switching component includes 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 may be composed of any power semiconductor element selected from insulated-gate bipolar transistors, silicon carbide power elements, silicon power elements, and / or gallium nitride power elements. Furthermore, the first switching component 2a and the second switching component 2b may be composed of different types of power semiconductor elements. For example, the first switching component 2a may be composed of silicon carbide, and the second switching component 2b may be composed of insulated-gate bipolar transistors.

[0068] In addition, the switch driver chip 3 includes a first switch driver circuit 31a and a second switch driver circuit 31b. The second switch driver circuit 31b is electrically connected to the output terminal of the comparator CP and the control terminal T4 of the second switch assembly 2b. The second switch driver circuit 31b is used to output a second control signal to the control terminal T4 to control the operation of the second switch assembly 2b. 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.

[0069] In addition, control loop 5a also includes a third input terminal Gate_IN1 and a third output terminal PWM_IN1. The third input terminal Gate_IN1 is electrically connected to the microcontroller unit to receive the control signal output by the microcontroller unit, and control loop 5a performs logic control with reference to the third input terminal Gate_IN1. The third output terminal PWM_IN1 is electrically connected to the second switch drive circuit 31b to provide another pulse width modulation signal according to the logic control of control loop 5a at the third input terminal Gate_IN1, so as to control the control terminal T4 of the second switching component 2b.

[0070] In some embodiments, the second switch driving circuit 31b includes 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. 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 a second switching signal to the switch switching circuit 313 based on the pulse width modulation signal output from the third output terminal PWM_IN1 and the comparator output signal Vd. The switch switching circuit 313 includes 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 conduction terminal of the first switch Q3 is electrically connected to the second voltage source VDD2. The second voltage source VDD2 is 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 conduction terminal of the second switch Q4 is electrically connected to the second current conduction terminal of the first switch Q3 and the control terminal T1 of the second switch assembly 2b. The second control signal output by the second switch drive circuit 31b is transmitted to the second switch assembly 2b through the first current conduction terminals of the second switch Q4 and the second current conduction terminals of the first switch Q3. The first current conduction terminal of the second switch Q2 is electrically connected to the ground terminal. When the second switch assembly 2b malfunctions and short-circuits, causing the comparator output signal Vd to be a high-level voltage, the fourth control signal output by the logic circuit 312 controls the third switch Q3 to turn off and the fourth switch Q4 to turn on, thereby controlling the second switch assembly 2b to disconnect to protect the second switch assembly 2b.

[0071] In addition, in some embodiments, the power circuit 1a also includes a third current source CS3, which is electrically connected between the first current conduction terminal of the first switch Q3 of the second switch drive circuit 31b and the first terminal of the capacitor Cblk, and is composed of a 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 assembly 2a even when the capacitance value is increased.

[0072] Furthermore, in some embodiments, the voltage source VDD is supplied to the first voltage source VDD1 and the second voltage source VDD2 with different voltages according to the Vgs specifications of the first switching component 2a and the second switching component 2b, respectively. For example, when the Vgs specifications of the first switching component 2a and the second switching component 2b are different, the voltage source VDD is supplied to the first voltage source VDD1 and the second voltage source VDD2 with different voltages, respectively. For instance, if the first switching component 2a is selected as an IGBT with a Vgs of 15V and the second switching component 2b is selected as a GaN with a Vgs of 8V, the VDD voltage is respectively regulated to supply a 15V voltage source to the first voltage source VDD1 and an 8V voltage source to the second voltage source VDD.

[0073] 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 the system where the power circuit is located via peripheral circuits (not shown in the figure). For example, if the power circuit is located on the motherboard, then the motherboard provides different voltage sources.

[0074] Please see Figure 4A , Figure 4B , Figure 4C and Figure 4D , Figures 4A to 4D They are respectively Figure 3 The diagram shows the waveforms 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 in different modes of the power circuit. First, if the first switching component 2a and the second switching component 2b are operating in the first mode, i.e. Figure 4A As shown, 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-level voltage, such as 14V, when the first switching component 2a and the second switching component 2b begin to conduct. Here, 14V is the voltage corresponding to the current protection response time of the second switching component 2b, which is 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-level voltage, such as 6V, where 6V is the voltage corresponding to the current protection response time of the first switching component 2a, which is composed of silicon carbide. When the first switching component 2a and the second switching component 2b begin to turn off from fully turned on, the reference voltage provided by the voltage source Uref can be adjusted to the first-level voltage.

[0075] If the first switch assembly 2a and the second switch assembly 2b operate in the second mode, that is Figure 4BAs shown, the first switching component 2a and the second switching component 2b are turned on simultaneously, but the first switching component 2a begins to turn off later than the second switching component 2b. Therefore, the reference voltage provided by the voltage source Uref can be adjusted to a first-level voltage when the first switching component 2a and the second switching component 2b begin to turn on. 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-level voltage. When the second switching component 2b begins to turn off from being fully turned on, the reference voltage provided by the voltage source Uref can be adjusted to a second-level voltage.

[0076] If the first switch assembly 2a and the second switch assembly 2b operate in the third mode, that is Figure 4C As shown, the first switch component 2a starts conducting earlier than the second switch component 2b, and the first switch component 2a starts turning off later than the second switch component 2b. Therefore, the reference voltage provided by the voltage source Uref can be adjusted to the second level voltage when the first switch component 2a starts conducting. When both the first switch component 2a and the second switch component 2b are fully conducting, the reference voltage provided by the voltage source Uref can be adjusted to the second level voltage. When the second switch component 2b starts turning off from fully conducting, the reference voltage provided by the voltage source Uref can be adjusted to the second level voltage.

[0077] If the first switch assembly 2a and the second switch assembly 2b operate in the fourth mode, that is Figure 4D As shown, the second switch component 2b starts conducting earlier than the first switch component 2a, while the first switch component 2a starts turning off later than the second switch component 2b. Therefore, the reference voltage provided by the voltage source Uref can be adjusted to a first-level voltage when the second switch component 2b starts conducting. When both the first and second switch components 2a are fully conducting, the reference voltage provided by the voltage source Uref can be adjusted to a second-level voltage. When the second switch component 2b begins to turn off from its fully conducting state, the reference voltage provided by the voltage source Uref can be adjusted to a second-level voltage.

[0078] Please see Figure 5 It is for application Figure 1 The flowchart illustrates the steps of a control method for a power circuit. The control method of this embodiment can be applied to… Figure 1 The power circuit 1 shown includes the following steps.

[0079] Step (S1) involves adjusting the reference voltage value based on the capacitance value of capacitor Cblk and the switching specifications of the first switching component 2a.

[0080] In step (S2), when the capacitor voltage of 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 open.

[0081] Please see Figure 6 It is for application Figure 3 The flowchart shown illustrates the steps of the control method for the power circuit. The control method of this embodiment can be applied to... Figure 3 The power circuit 1a shown includes the following steps.

[0082] Step (S10): The voltage value of the reference voltage is adjusted according to the capacitance value of capacitor Cblk and the switching specifications of the first switching component 2a and the second switching component 2b.

[0083] In step (S20), when the capacitor voltage of 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 open, 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 open.

[0084] In some embodiments, if the first switch component 2a and the second switch component 2b are simultaneously turned on and off, then in step (S1), the reference voltage provided by the voltage source Uref can be adjusted to a first level voltage when the first switch component 2a and the second switch component 2b begin to turn 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 a second level voltage, and when the first switch component 2a and the second switch component 2b begin to turn off from being fully turned on, the reference voltage provided by the voltage source Uref can be adjusted to a first level voltage.

[0085] In some embodiments, if the first switch component 2a and the second switch component 2b are turned on simultaneously, and the first switch component 2a begins to turn off later than the second switch component 2b begins to turn off, then in step (S1), the reference voltage provided by the voltage source Uref can be adjusted to a first level voltage when the first switch component 2a and the second switch component 2b begin to turn 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 a second level voltage, and when the second switch component 2b begins to turn off from being fully turned on, the reference voltage provided by the voltage source Uref can be adjusted to a second level voltage.

[0086] In some embodiments, if the first switch component 2a starts conducting earlier than the second switch component 2b starts conducting, and the first switch component 2a starts turning off later than the second switch component 2b starts turning off, then in step (S1), the reference voltage provided by the voltage source Uref can be adjusted to a second level voltage when the first switch component 2a starts conducting, and when the first switch component 2a and the second switch component 2b are fully conducting, the reference voltage provided by the voltage source Uref can be adjusted to a second level voltage, and when the second switch component 2b starts turning off from being fully conducting, the reference voltage provided by the voltage source Uref can be adjusted to a second level voltage.

[0087] In some embodiments, if the second switch component 2b starts conducting earlier than the first switch component 2a starts conducting, and the first switch component 2a starts turning off later than the second switch component 2b starts turning off, then in step (S1), the reference voltage provided by the voltage source Uref can be adjusted to a first level voltage when the second switch component 2b starts conducting, and when the first switch component 2a and the second switch component 2b are fully conducting, the reference voltage provided by the voltage source Uref can be adjusted to a second level voltage, and when the second switch component 2b starts turning off from being fully conducting, the reference voltage provided by the voltage source Uref can be adjusted to a second level voltage.

[0088] In summary, this invention provides a power circuit and a suitable control method thereof. The inverting input terminal of the comparator in the switch driving circuit within the switch driving chip is electrically connected to an adjustable voltage source to receive a reference voltage provided by the adjustable voltage source. Therefore, the current protection response time of switch components with different characteristics can be satisfied by adjusting the reference voltage, thereby protecting switch components of different specifications. Thus, the power circuit of this invention has high versatility.

Claims

1. A power circuit, characterized in that, Include: At least one switching component, each of the switching components includes a control terminal, a first current conduction terminal and a second current conduction terminal, wherein the at least one switching component includes a first switching component; A switch driver chip for controlling the operation of the at least one switch assembly, and comprising: A desaturation detection circuit includes a comparator, a non-inverting input terminal of the comparator being electrically connected to a first current source and each of the first current conduction terminals, and an inverting input terminal of the comparator being electrically connected to an adjustable voltage source to receive a reference voltage provided by the adjustable voltage source. as well as A first switch driving circuit is electrically connected to an output terminal of the comparator and a control terminal of the first switch assembly. The first switch driving circuit is used to output a first control signal to the control terminal according to a comparator output signal output from the output terminal of the comparator, so as to control the operation of the first switch assembly. as well as A clamping circuit, electrically connected between the non-inverting input terminal and each of the first current conduction terminals, is used to clamp the voltage on the non-inverting input terminal when the at least one switching component is turned on; and A capacitor is electrically connected between the non-inverting input terminal and a ground terminal, and has a capacitor voltage; wherein the voltage value of the reference voltage is adjusted according to the capacitance value of the capacitor and the switching specifications of the at least one switching component, and when the capacitor voltage is greater than the reference voltage, the first switch driving circuit controls the first switching component to open.

2. The power circuit according to claim 1, characterized in that, The reference voltage is generated internally by the switch driver chip or provided by an external voltage connected to a pin of the switch driver chip.

3. The power circuit according to claim 1, characterized in that, The clamping circuit includes a first resistor and a first diode. A first end of the first resistor is electrically connected to the non-inverting input terminal of the comparator, a second end of the first resistor is electrically connected to the anode terminal of the first diode, and a cathode terminal of the first diode is electrically connected to the first current conduction terminal of the first switching assembly.

4. The power circuit according to claim 1, characterized in that, The capacitance value of this capacitor is 1000pF.

5. The power circuit according to claim 1, characterized in that, The power circuit also includes a second current source electrically connected between the first switch drive circuit and the capacitor, and is composed of a second resistor. The second current source is used to generate an additional charging current to charge the capacitor.

6. The power circuit according to claim 1, characterized in that, The power circuit also includes a first voltage protection circuit, which is composed of a second diode. One cathode of the second diode is electrically connected to a voltage source, and one anode of the second diode is electrically connected between the clamping circuit and the non-inverting input terminal of the comparator.

7. The power circuit according to claim 1, characterized in that, The power circuit also includes a second voltage protection circuit, which is composed of a Zener diode, wherein one cathode of the Zener diode is electrically connected between the clamping circuit and the non-inverting input terminal of the comparator, and one anode of the Zener diode is electrically connected to the ground terminal.

8. The power circuit according to claim 1, characterized in that, The switching assembly further includes a second switching assembly, wherein the first switching assembly and the second switching assembly are different types of power semiconductor elements.

9. The power circuit according to claim 8, characterized in that, The first switching component and the second switching component have different current protection response times, and the switching driver chip also includes a second switching driver circuit. The second switching driver circuit is electrically connected to the output terminal of the comparator and the control terminal of the second switching component. The second switching driver circuit is used to output a second control signal to the control terminal of the second switching component according to the comparator output signal, so as to control the operation of the second switching component.

10. The power circuit according to claim 9, characterized in that, The first switching component and the second switching component are simultaneously turned on and off. When the first switching component and the second switching component begin to turn on, the reference voltage is adjusted to a first level voltage, wherein the first level voltage is the voltage corresponding to the current protection response time of the second switching component. When the first switching component and the second switching component are fully turned on, the reference voltage is adjusted to a second level voltage, wherein the second level voltage is the voltage corresponding to the current protection response time of the first switching component. When the first switching component and the second switching component begin to turn off from being fully turned on, the reference voltage is adjusted to the first level voltage.

11. The power circuit according to claim 9, characterized in that, The first switching component and the second switching component are turned on simultaneously, and the first switching component starts to turn off later than the second switching component starts to turn off. The reference voltage is adjusted to a first level voltage when the first switching component and the second switching component start to turn on, and to a second level voltage when the first switching component and the second switching component are fully turned on. The reference voltage is adjusted to the second level voltage when the second switching component starts to turn off from being fully turned on.

12. The power circuit according to claim 9, characterized in that, The first switching component starts conducting earlier than the second switching component starts conducting, and the first switching component starts turning off later than the second switching component starts turning off. The reference voltage is adjusted to a second level voltage when the first switching component starts conducting, and is adjusted to the second level voltage when the first and second switching components are fully conducting. The reference voltage is adjusted to the second level voltage when the second switching component starts turning off from full conduction.

13. The power circuit according to claim 9, characterized in that, The second switching component starts conducting earlier than the first switching component starts conducting, and the first switching component starts turning off later than the second switching component starts turning off. The reference voltage is adjusted to a first level voltage when the second switching component starts conducting, and to a second level voltage when the first and second switching components are fully conducting. When the second switching component starts turning off from being fully conducting, the reference voltage is adjusted to the second level voltage.

14. The power circuit according to claim 9, characterized in that, The voltage source supplies different voltages to a first voltage source and a second voltage source respectively through voltage regulation according to the Vgs specifications of the first switching assembly and the second switching assembly.

15. A control method, characterized in that, This invention relates to a power circuit comprising at least one switching assembly, a switching driver chip, a clamping circuit, and a capacitor. Each switching assembly includes a control terminal, a first current conduction terminal, and a second current conduction terminal. The at least one switching assembly includes a first switching assembly. The switching driver chip controls the operation of the at least one switching assembly and includes a desaturation detection circuit and a first switching drive circuit. The desaturation detection circuit includes a comparator. A non-inverting input of the comparator is electrically connected to a first current source and each of the first current conduction terminals. An inverting input of the comparator is electrically connected to an adjustable voltage source to receive voltage signals. The adjustable voltage source provides a reference voltage. The first switch driving circuit is electrically connected to an output terminal of the comparator and the corresponding control terminal of the switching assembly. The first switch driving circuit outputs a first control signal to the control terminal according to a comparator output signal output from the comparator output terminal to control the operation of the first switching assembly. The clamping circuit is electrically connected between the non-inverting input terminal and each of the first current conduction terminals to clamp the voltage on the non-inverting input terminal when at least one switching assembly is turned on. The capacitor is electrically connected between the non-inverting input terminal and a ground terminal and has a capacitor voltage. The control method includes: (S1) The voltage value of the reference voltage is adjusted according to the capacitance value of the capacitor and the switching specifications of the first switching assembly; as well as (S2) When the capacitor voltage is greater than the reference voltage, the first switch drive circuit outputs the first control signal according to the comparator output signal to control the first switch component to open.

16. The control method according to claim 15, characterized in that, The at least one of the switching components further includes a second switching component. The first switching component and the second switching component are different types of power semiconductor devices, and the first switching component and the second switching component have different current protection response times. The switch driver chip also includes a second switching driver circuit, which is electrically connected to the output terminal of the comparator and the control terminal of the second switching component. The second switching driver 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 step (S1), the voltage value of the reference voltage is also adjusted according to the switching specifications of the second switching component. In step (S2), when the capacitor voltage is greater than the reference voltage, the second switching driver circuit outputs a second control signal according to the comparator output signal to control the second switching component to disconnect.

17. The control method according to claim 16, characterized in that, The first switching component and the second switching component are simultaneously turned on and off. In step (S1), the reference voltage is adjusted to a first level voltage when the first switching component and the second switching component begin to turn on, wherein the first level voltage is the voltage corresponding to the current protection response time of the second switching component. When the first switching component and the second switching component are fully turned on, the reference voltage is adjusted to a second level voltage, wherein the second level voltage is the voltage corresponding to the current protection response time of the first switching component. When the first switching component and the second switching component begin to turn off from being fully turned on, the reference voltage is adjusted to the first level voltage.

18. The control method according to claim 16, characterized in that, The first switching component and the second switching component are turned on simultaneously, and the first switching component starts to turn off later than the second switching component starts to turn off. In this step (S1), the reference voltage is adjusted to a first level voltage when the first switching component and the second switching component start to turn on, and the reference voltage is adjusted to a second level voltage when the first switching component and the second switching component are fully turned on. When the second switching component starts to turn off from being fully turned on, the reference voltage is adjusted to the second level voltage.

19. The control method according to claim 16, characterized in that, The first switching component starts conducting earlier than the second switching component starts conducting, and the first switching component starts turning off later than the second switching component starts turning off. In this step (S1), the reference voltage is adjusted to a second level voltage when the first switching component starts conducting, and when the first and second switching components are fully conducting, the reference voltage is adjusted to the second level voltage. When the second switching component starts turning off from being fully conducting, the reference voltage is adjusted to the second level voltage.

20. The control method according to claim 16, characterized in that, The second switching component starts conducting earlier than the first switching component starts conducting, and the first switching component starts turning off later than the second switching component starts turning off. In step (S1), the reference voltage is adjusted to a first level voltage when the second switching component starts conducting, and to a second level voltage when the first and second switching components are fully conducting. When the second switching component starts turning off from being fully conducting, the reference voltage is adjusted to the second level voltage.

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