TW202608024A - Power circuit and control method thereof - Google Patents

Abstract

A power circuit is disclosed. The power circuit comprises a switch assembly, a switch driving chip, a clamp circuit and a capacitor. The switch assembly comprises a control terminal, a first current conducting terminal and a second current conducting terminal. The switch driving chip comprises a switch driving circuit and a desaturation detection circuit with a comparator. A non-inverting input terminal of the comparator is electrically connected to a current source and the first current conduction terminal, and an inverting input terminal of the comparator receives a reference voltage. The switch driving circuit outputs a first control signal to control the switch assembly according to a comparator output signal output by the comparator. The clamp circuit clamps a voltage on the non-inverting input terminal when the switch assembly is turned on. The capacitor is electrically connected to the non-inverting input terminal and a ground terminal. A voltage value of the reference voltage is controlled according to a capacitance value of the capacitor and the switch specification of the switch assembly. When a capacitor voltage of the capacitor is greater than the reference voltage, the switch driving circuit controls the switch assembly to be turned off.

Description

Power circuits and their applicable control methods

This case falls within the technical field of power circuits, specifically referring to a power circuit that optimizes the protection of switching components and the control method applicable thereto.

In general power circuits, such as those used in electric vehicle drives, there is at least one switching component. The switching component can be any of the following power semiconductor devices: insulated gate bipolar transistor (IGBT), silicon carbide power device (SiC-MOSFET), silicon power device (Si-MOSFET), and/or gallium nitride power device (GaN FET), to switch voltage and/or current by switching the switching component.

However, different switching components have different switching specifications and characteristics. For example, when the switching component is composed of an insulated gate bipolar transistor or silicon carbide, the current protection response time of the insulated gate bipolar transistor and silicon carbide differs greatly. That is, the current protection response time of the insulated gate bipolar transistor is about 10µs, while that of silicon carbide is about [missing information]. The current protection time is 2µs, so the same protection circuit cannot meet both requirements at the same time. For example, when silicon carbide protection circuit is used to protect insulated gate bipolar transistors, the current protection response time of the insulated gate bipolar transistors may be slow, which may cause the protection circuit to be easily interfered with and pose a risk of protection malfunction. Therefore, the versatility of traditional power circuits is not good.

Therefore, how to develop power circuits that can protect switching components with different specifications and characteristics, and the control methods applicable to them, is an urgent issue that needs to be addressed in this field.

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

To achieve the above objectives, one embodiment of this invention provides a power circuit comprising: at least one switching component, including a control terminal, a first current conducting terminal, and a second current conducting terminal, wherein the at least one switching component includes a first switching component; a switching driver chip for controlling the operation of the at least one switching component, and comprising: a desaturation detection circuit including a comparator, wherein the non-inverting input terminal of the comparator is electrically connected to a first current source and each first current conducting terminal, and 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; and a first switching driver circuit electrically connected to the output terminal of the comparator and the control terminal of the first switching component. The first switch drive 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, electrically connected between the non-inverting input terminal and each first current conduction terminal, is used to clamp the voltage on the non-inverting input terminal when at least one switch component is turned on; and a capacitor, electrically connected between the non-inverting input terminal and the ground terminal, and having 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 at least one switch component, and when the capacitor voltage is greater than the reference voltage, the first switch drive circuit controls the first switch component to turn off.

To achieve the above objectives, another embodiment of this application provides a control method for use in a power circuit. The power circuit includes at least one switching component, a switching driver chip, a clamping circuit, and a capacitor. Each switching component includes a control terminal, a first current-carrying terminal, and a second current-carrying terminal. At least one switching component includes a first switching component. The switching driver chip is used to control the at least one switching component. The device operates and includes a desaturation detection circuit and a first switch driver circuit. The desaturation detection circuit includes a comparator. The non-inverting input of the comparator is electrically connected to a first current source and each first current conduction terminal. The inverting input 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 driver circuit is connected to the output of the comparator and a corresponding switch. The control terminal of the component is electrically connected. The first switch driver circuit outputs a first control signal to the control terminal according to the comparator output signal, thereby controlling the operation of the first switching component. The clamping circuit is electrically connected between the non-inverting input terminal and each first current conduction terminal to clamp the voltage on the non-inverting input terminal when at least one switching component is turned on. The capacitor is electrically connected. Between the non-reverse input terminal and the ground terminal, and having 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 switching component; and (S2) when the capacitor voltage is greater than the reference voltage, the first switching drive circuit outputs a first control signal according to the comparator output signal to control the first switching component to open.

Some typical implementations that embody the characteristics and advantages of this case will be described in detail in the following section. It should be understood that this case can have various variations in different forms, all of which do not depart from the scope of this case, and the descriptions and illustrations therein are essentially for illustrative purposes, rather than constituting a framework for limiting this case.

Please refer to Figure 1, which 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 to, for example, an electric vehicle drive, and includes at least one switching component, a switching driver chip 3, a clamping circuit 4, and a capacitor Cblk. The at least one switching component, such as the first switching component 2a shown in Figure 1, can be, but is not limited to, any power semiconductor device selected from insulated gate bipolar transistors, silicon carbide power devices, silicon power devices, and/or gallium nitride power devices, and includes a control terminal T1, a first current conduction terminal T2, and a second current conduction terminal T3.

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 driver circuit. The desaturation detection circuit 30 is electrically connected to the first current conduction terminal T2 of the first switching component 2a and each switch driver circuit to provide a comparator output signal Vd to each switch driver 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 the adjustable voltage source Uref to receive a reference voltage provided by the adjustable voltage source Uref. The reference voltage value is adjusted according to the capacitance value of capacitor Cblk and the switching specifications of the first switching component 2a. In some embodiments, the first current source CS1 is further electrically connected to the voltage source VDD.

At least one switching drive circuit, such as the first switching drive circuit 31a shown in Figure 1, is electrically connected to the output terminal of the comparator CP and the control terminal T1 of the first switching component 2a. The first switching drive circuit 31a is used to output a first control signal to the control terminal T1 to control the operation of the corresponding first switching component 2a. The voltage level of the first control signal is 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.

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 the ground terminal G. Capacitor Cblk has a capacitive voltage.

When the first switching component 2a malfunctions and short-circuits, the capacitor voltage of capacitor Cblk increases and is reflected at the non-inverting input terminal of comparator CP, making the voltage at the non-inverting input terminal of 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 a corresponding first control signal to the control terminal T1 of the first switching component 2a to control the corresponding first switching component 2a to open and protect the first switching component 2a.

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 value of the adjustable voltage source Uref increases, so that the current protection response time of the first switching component 2a meets the requirement of 10µs. Conversely, when the first switching component 2a is made of silicon carbide, for example, the reference voltage value of the adjustable voltage source Uref becomes smaller, so that the current protection response time of the first switching component 2a is within 2µs. Therefore, the power circuit 1 of this invention can meet the current protection response time of the first switching component 2a regardless of the switching specification of the first switching component 2a, making the power circuit 1 highly versatile.

In some embodiments, the reference voltage of the adjustable voltage source Uref can be generated internally by the switch driver chip 3 or by an externally variable voltage connected to a pin of the switch driver chip 3. Additionally, the clamping circuit 4 includes a first resistor R1 and a first diode D1. The first terminal of the first resistor R1 is electrically connected to the non-inverting input terminal of the comparator CP, and the second terminal 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 power circuit 1, but is not limited thereto. 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.

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

In some embodiments, the first switching drive circuit 31a includes a logic circuit 310 and a 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. The logic circuit 310 outputs a first switching signal to the switching circuit 311 at its output terminal according to the pulse width modulation signal and the comparator output signal Vd. The 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. The first current conduction terminal of the first switch Q1 is electrically connected to the first voltage source VDD1, and 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 switching component 2a. The first control signal output by the first switch drive circuit 31a is transmitted to the first switching component 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 switching component 2a malfunctions and short-circuits, causing the comparator output signal Vd to reach a high level, 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 switching component 2a to turn off to protect the first switching component 2a.

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 increases.

Please refer to Figure 2, which is a schematic diagram of the power circuit structure of the second preferred embodiment of this invention. In some embodiments, as shown in Figure 2, the power circuit 1 further 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 protect against abnormal sudden transient high voltage (ELECTROSTATIC) events. The overvoltage protection circuit provides a conduction path under the overvoltage condition (ESD). To further explain, when an abnormal sudden transient high voltage occurs, causing the voltage at the anode of the second diode D2 to be greater than the voltage of the voltage source VDD, the second diode D2 conducts, allowing transient energy to flow into the circuit of the voltage source VDD. This transient energy is absorbed by the capacitor in its path, thereby achieving the function of overvoltage protection.

In other embodiments, the power circuit 1 further includes a second voltage protection circuit, which is composed of a receiver diode Z. The cathode of the receiver diode Z is 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 receiver diode Z is connected to the ground terminal G. The second voltage protection circuit can protect against abnormal sudden transient high voltage. The pressure provides a conduction path. To further explain, when an abnormal sudden high voltage occurs, causing the voltage at the cathode of the receiver diode Z to exceed its breakdown voltage, the receiver diode Z conducts. This allows transient energy to flow through the receiver diode Z into the ground terminal G instead of into the internal circuitry of the switch driver chip 3, thereby achieving overvoltage protection by changing the noise path. The power circuit 1 may include one or both of a first voltage protection circuit and a second voltage protection circuit.

Please refer to Figure 3, which is a schematic diagram of the power circuit structure of the third preferred embodiment of this case. Part of the circuit structure of power circuit 1a in this embodiment is similar to the circuit structure of power circuit 1 shown in Figure 2; therefore, the same symbols are used to indicate similar circuit structures, and further description is unnecessary. In this embodiment, power circuit 1a includes a first switching component 2a and a second switching component 2b. The second switching component includes a control terminal T4, a first current conducting terminal T5, and a second current conducting terminal T6. In some embodiments, the second switching component 2b may be composed of any power semiconductor device selected from insulated gate bipolar transistors, silicon carbide power devices, silicon power devices, and/or gallium nitride power devices, and the first switching component 2a and the second switching component 2b may be composed of different types of power semiconductor devices. 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.

In addition to the first switch driver circuit 31a, the switch driver chip 3 also includes 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 component 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 component 2b. The voltage level of the second control signal is 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.

Furthermore, control circuit 5a 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 (MCU) to receive the control signal output by the MCU, and control circuit 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 drive circuit 31b to provide another pulse width modulation signal according to the logical control of control circuit 5a at the third input terminal Gate_IN1, so as to control the control terminal T4 of the second switching component 2b.

In some embodiments, the second switch drive 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 circuit 5a to receive the pulse width modulation signal. The logic circuit 310 outputs a second switching signal to the switch switching circuit 313 at its output terminal 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. The first current conduction terminal of the first switch Q3 is electrically connected to the second voltage source VDD2, and 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 switching component 2b. The second control signal output by the second switch drive circuit 31b is transmitted to the second switching component 2b through the first current conduction terminal of the second switch Q4 and the second current conduction terminal 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 switching component 2b malfunctions and short-circuits, causing the comparator output signal Vd to be at a high level, 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 switching component 2b to turn off to protect the second switching component 2b.

Furthermore, in some embodiments, the power circuit 1a further 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 increases.

Furthermore, in some embodiments, based on the Vgs specifications of the first switching component 2a and the second switching component 2b, the voltage source VDD is supplied to the first voltage source VDD1 and the second voltage source VDD2 at different voltages through separate voltage regulation. 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 at different voltages through separate voltage regulation. For instance, if the first switching component 2a is selected with an IGBT of 15V Vgs and the second switching component 2b is selected with an 8V Vgs value... When using GaN, the VDD voltage is adjusted to supply a 15V voltage source to the first voltage source VDD1 and an 8V voltage source to the second voltage source VDD.

In the aforementioned 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 through 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.

Please refer to Figures 4A, 4B, 4C, and 4D. Figures 4A to 4D are waveform diagrams showing 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 in Figure 3. First, if the first switching component 2a and the second switching component 2b operate in the first mode, as shown in Figure 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 adjustable voltage source Uref is adjusted to the first level voltage, for example, 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 adjustable 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 made of silicon carbide. When the first switching component 2a and the second switching component 2b are turned off from the fully turned-on state, the reference voltage provided by the adjustable voltage source Uref can be adjusted to a first level voltage.

If the first switching component 2a and the second switching component 2b operate in the second mode, as shown in Figure 4B, where both components are simultaneously turned on, but the first switching component 2a begins to turn off later than the second switching component 2b, then the reference voltage provided by the adjustable voltage source Uref is adjusted to the first level voltage when both components begin to turn on. When both components are fully turned on, the reference voltage provided by the adjustable voltage source Uref is adjusted to the second level voltage. When the second switching component 2b begins to turn off from fully turned on, the reference voltage provided by the adjustable voltage source Uref is adjusted to the second level voltage.

If the first switching component 2a and the second switching component 2b operate in the third mode, as shown in Figure 4C, where the first switching component 2a begins to conduct earlier than the second switching component 2b, and the first switching component 2a begins to turn off later than the second switching component 2b, then the reference voltage provided by the adjustable voltage source Uref is adjusted to the second level voltage when the first switching component 2a begins to conduct. When the first switching component 2a and the second switching component 2b are fully conducting, the reference voltage provided by the adjustable voltage source Uref is adjusted to the second level voltage. When the second switching component 2b begins to turn off from fully conducting, the reference voltage provided by the adjustable voltage source Uref is adjusted to the second level voltage.

If the first switching component 2a and the second switching component 2b operate in the fourth mode, as shown in Figure 4D, where the second switching component 2b begins to conduct earlier than the first switching component 2a, and the first switching component 2a begins to turn off later than the second switching component 2b, then the reference voltage provided by the adjustable voltage source Uref is adjusted to the first level voltage when the second switching component 2b begins to conduct. When the first switching component 2a and the second switching component 2b are fully conducting, the reference voltage provided by the adjustable voltage source Uref is adjusted to the second level voltage. When the second switching component 2b begins to turn off from fully conducting, the reference voltage provided by the adjustable voltage source Uref is adjusted to the second level voltage.

Please refer to Figure 5, which is a flowchart of the control method applied to the power circuit shown in Figure 1. The control method of this embodiment can be applied to the power circuit 1 shown in Figure 1 and includes the following steps.

Step (S1): Adjust the reference voltage value according to the capacitance value of capacitor Cblk and the switching specifications of the first switching component 2a.

In step (S2), when the capacitor voltage of capacitor Cblk is greater than the reference voltage, the first switch drive circuit 31a outputs a first control signal according to the comparator output signal to control the first switch component 2a to turn off.

Please refer to Figure 6, which is a flowchart of the control method applied to the power circuit shown in Figure 3. The control method of this embodiment can be applied to the power circuit 1a shown in Figure 3 and includes the following steps.

Step (S10): Adjust the voltage value of the reference voltage according to the capacitance value of capacitor Cblk and the switching specifications of the first switching component 2a and the second switching component 2b.

In step (S20), when the capacitor voltage of capacitor Cblk is greater than the reference voltage, the first switch drive 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 drive circuit 31b outputs a second control signal according to the comparator output signal to control the second switch component 2b to open.

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

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

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

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

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

1. 1a: Power circuit 3: Switch driver chip 4: Clamping circuit Cblk: Capacitor 2a: First switching component T1, T4: Control terminals T2, T5: First current conduction terminals T3, T6: Second current conduction terminals G: Ground terminal 30: Desaturation detection circuit CP: Comparator CS1: First current source Uref: Adjustable voltage source VDD: Voltage source 31a: First switch driver circuit Vd: Comparator output signal R1: First resistor D1: First diode 5. 5a: Control circuit 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: Zener 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: Control Method Steps

Figure 1 is a schematic diagram of the power circuit structure of the first preferred embodiment of this invention; Figure 2 is a schematic diagram of the power circuit structure of the second preferred embodiment of this invention; Figure 3 is a schematic diagram of the power circuit structure of the third preferred embodiment of this invention; Figures 4A, 4B, 4C, and 4D are respectively schematic diagrams of 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 in Figure 3; Figure 5 is a flowchart of the steps of the control method applied to the power circuit shown in Figure 1; and Figure 6 is a flowchart of the steps of the control method applied to the power circuit shown in Figure 3.

1: Power Circuit

3: Switch driver chip

4: Clamping Circuit

Cblk: Capacitor C ...ellular

2a: First switching component

T1: Control terminal

T2: First current conduction terminal

T3: Second current conduction terminal

G: Grounding terminal

30: Desaturation Detection Circuit

CP: Comparator

CS1: First Current Source

Uref: Adjustable voltage source

VDD: Voltage source

31a: First Switch Drive Circuit

Vd: Comparator output signal

R1: First resistor

D1: First Dipolar Body

5: Control loop

Fault: First Input Terminal

Fautt_out: First output terminal

Gate_IN: Second input terminal

PWM_IN: Second output terminal

310: Logic Circuits

311: Switching circuit

Q1: First switch

Q2: Second switch

CS2: Second Current Source

R2: Second resistor

Claims (20)

A power circuit comprising: at least one switching component, each switching component including a control terminal, a first current conducting terminal, and a second current conducting terminal, wherein the at least one switching component includes a first switching component; a switching driver chip for controlling the operation of the at least one switching component, and comprising: a desaturation detection circuit including a comparator, a non-inverting input terminal of the comparator electrically connected to a first current source and each of the first current conducting terminals, and an inverting input terminal of the comparator electrically connected to an adjustable voltage source to receive a reference voltage provided by the adjustable voltage source; and A first switch driver circuit is electrically connected to an output terminal of the comparator and a control terminal of the first switching assembly. The first switch driver circuit outputs a first control signal to the control terminal in response to a comparator output signal from the comparator output terminal, thereby controlling the operation of the first switching assembly. A clamping circuit is electrically connected between the non-inverting input terminal and each of the first current conducting terminals, for clamping the voltage on the non-inverting input terminal when the at least one switching assembly is turned on. A capacitor is electrically connected between the non-inverting input terminal and a ground terminal, and has a capacitor voltage. The reference voltage is adjusted based on the capacitance value of the capacitor and the switching specifications of the at least one switching component. When the capacitor voltage is greater than the reference voltage, the first switching drive circuit controls the first switching component to open. The power circuit as described in claim 1, wherein 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. The power circuit as claimed in claim 1, wherein the clamping circuit includes a first resistor and a first diode, a first terminal of the first resistor is electrically connected to the non-inverting input terminal of the comparator, a second terminal 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 component. The power circuit as described in claim 1, wherein the capacitance value of the capacitor is 1000pF. The power circuit as claimed in claim 1, wherein the power circuit further includes a second current source electrically connected between the first switch drive circuit and the capacitor, and consisting of a second resistor, the second current source being used to generate an additional charging current to charge the capacitor. The power circuit as claimed in claim 1, wherein the power circuit further includes a first voltage protection circuit, the first voltage protection circuit being composed of a second diode, a cathode terminal of the second diode being connected to a voltage source, and an anode terminal of the second diode being connected between the clamping circuit and the non-inverting input terminal of the comparator. The power circuit as claimed in claim 1, further comprising a second voltage protection circuit, the second voltage protection circuit being composed of a Zener diode, wherein a cathode terminal of the Zener diode is electrically connected between the clamping circuit and the non-inverting input terminal of the comparator, and an anode terminal of the Zener diode is electrically connected to the ground terminal. The power circuit as claimed in claim 1, wherein the switching component further includes a second switching component, the first switching component and the second switching component being of different power semiconductor device types. The power circuit as described in claim 8, wherein the first switching component and the second switching component have different current protection response times, and the switching driver chip further 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 in accordance with the output signal of the comparator, so as to control the operation of the second switching component. The power circuit of claim 9, wherein the first switching component and the second switching component are simultaneously turned on and off, and the reference voltage is adjusted to a first level voltage when the first switching component and the second switching component begin to conduct, 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; and 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. The power circuit of claim 9, wherein the first switching component and the second switching component are simultaneously turned on, and the first switching component begins to turn off later than the second switching component begins to turn off, and the reference voltage is adjusted to a first level voltage when the first switching component and the second switching component begin to turn on, and is adjusted to a second level voltage when the first switching component and the second switching component are fully turned on, and is adjusted to the second level voltage when the second switching component begins to turn off from being fully turned on. The power circuit of claim 9, wherein the first switching component begins to conduct earlier than the second switching component begins to conduct, and the first switching component begins to turn off later than the second switching component begins to turn off, and the reference voltage is adjusted to a second level voltage when the first switching component begins to conduct, and when the first switching component and the second switching component are fully conducting, the reference voltage is adjusted to the second level voltage, and when the second switching component turns off from fully conducting, the reference voltage is adjusted to the second level voltage. The power circuit of claim 9, wherein the second switching component begins to conduct earlier than the first switching component begins to conduct, and the first switching component begins to turn off later than the second switching component begins to turn off, and the reference voltage is adjusted to a first level voltage when the second switching component begins to conduct, the reference voltage is adjusted to a second level voltage when the first and second switching components are fully conducting, and the reference voltage is adjusted to the second level voltage when the second switching component begins to turn off from fully conducting. The power circuit as described in claim 9, wherein the voltage source supplies different voltages to a first voltage source and a second voltage source respectively via voltage regulation according to the Vgs specifications of the first switching component and the second switching component. A control method is applied to a power circuit, the power circuit including at least one switching component, a switching driver chip, a clamping circuit, and a capacitor, wherein each of the switching components includes a control terminal, a first current conducting terminal, and a second current conducting terminal, and the at least one switching component includes a first switching component; the switching driver chip is used to control the operation of the at least one switching component, and includes a desaturation detection circuit and a first switching driver circuit, the desaturation detection circuit including a comparator, a non-inverting input terminal of the comparator being electrically connected to a first current source and each of the first current conducting terminals, and an inverting input terminal of the comparator being electrically connected to an adjustable voltage source. The control method includes receiving a reference voltage from an adjustable voltage source. A first switch driver circuit is electrically connected to an output terminal of the comparator and a corresponding control terminal of the switching component. The first switch driver circuit outputs a first control signal to the control terminal based on a comparator output signal from the comparator's output terminal to control the operation of the first switching component. A 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 component is turned on. A capacitor is electrically connected between the non-inverting input terminal and a ground terminal and has a capacitive 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 component; and (S2) When the capacitor voltage is greater than the reference voltage, the first switching drive circuit outputs the first control signal corresponding to the comparator output signal to control the first switching component to turn off. The control method as described in claim 15, wherein the at least one switching component further includes a second switching component, the first switching component and the second switching component are different power semiconductor device types, and the first switching component and the second switching component have different current protection response times, and the switching driver chip further includes a second switching driver circuit, the second switching driver circuit being electrically connected to the output terminal of the comparator and the control terminal of the second switching component, the second switching driver circuit... The 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. In step (S1), the voltage value of the reference voltage is further 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 drive circuit outputs a second control signal according to the comparator output signal, so as to control the second switching component to turn off. The control method of claim 16, wherein the first switching component and the second switching component are simultaneously turned on and off, and 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 conduct, wherein the first level voltage is the voltage corresponding to the current protection response time of the second switching component, and 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, and 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. The control method of claim 16, wherein the first switching component and the second switching component are simultaneously turned on, and the first switching component begins to turn off later than the second switching component begins to turn off, and 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, and is adjusted to a second level voltage when the first switching component and the second switching component are fully turned on, and is adjusted to the second level voltage when the second switching component begins to turn off from being fully turned on. The control method of claim 16, wherein the first switching component begins to conduct earlier than the second switching component begins to conduct, and the first switching component begins to turn off later than the second switching component begins to turn off, and in step (S1), the reference voltage is adjusted to a second level voltage when the first switching component begins to conduct, and when the first switching component and the second switching component are fully conducting, the reference voltage is adjusted to the second level voltage, and when the second switching component begins to turn off from fully conducting, the reference voltage is adjusted to the second level voltage. The control method of claim 16, wherein the second switching component begins to conduct earlier than the first switching component begins to conduct, and the first switching component begins to turn off later than the second switching component begins to turn off, and in step (S1), the reference voltage is adjusted to a first level voltage when the second switching component begins to conduct, the reference voltage is adjusted to a second level voltage when the first switching component and the second switching component are fully conducting, and the reference voltage is adjusted to the second level voltage when the second switching component begins to turn off from fully conducting.