CN111342647A - Current-limiting protection method and circuit for high-side power switch - Google Patents
Current-limiting protection method and circuit for high-side power switch Download PDFInfo
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- CN111342647A CN111342647A CN202010238204.4A CN202010238204A CN111342647A CN 111342647 A CN111342647 A CN 111342647A CN 202010238204 A CN202010238204 A CN 202010238204A CN 111342647 A CN111342647 A CN 111342647A
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- 238000005070 sampling Methods 0.000 claims abstract description 153
- 238000007599 discharging Methods 0.000 claims abstract description 15
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/32—Means for protecting converters other than automatic disconnection
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/0003—Details of control, feedback or regulation circuits
- H02M1/0038—Circuits or arrangements for suppressing, e.g. by masking incorrect turn-on or turn-off signals, e.g. due to current spikes in current mode control
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Abstract
The invention discloses a current-limiting protection method and a circuit for a high-side power switch, wherein the method comprises the following steps: generating a trigger signal according to a sampling parameter, wherein the sampling parameter is sampling current or sampling voltage; discharging a gate charge of a main power transistor of the high-side power switch based on the trigger signal; the sampling current is the current which is characterized to flow through the main power tube, and the sampling voltage is the voltage which is characterized to be applied to the main power tube, so that when the parameters in the high-side power switch meet the short-circuit or overload protection condition, the grid voltage of the main power tube is reduced relative to the drain voltage VGS, the current value flowing through the main power tube is reduced, the main power tube is prevented from being damaged due to delay protection during short-circuit or overload, and the stability and the reliability of the high-side power switch are further improved.
Description
Technical Field
The present disclosure relates to the field of switching power supply technologies, and more particularly, to a current limiting protection method and circuit for a high-side power switch.
Background
The high-side power switch is an economic and efficient integrated power switch of an analog circuit and a powerful load/output driver, is used as a key device for controlling circuits such as a motor, a relay and lighting, and plays a significant role in the efficiency, reliability and the like of systems such as an aviation equipment flight control system, an electric power system and a lighting system.
The traditional high-side power switch comprises a main power tube, a sampling power tube, a logic circuit, a driving circuit, a protection circuit and the like, and in order to realize short-circuit or overload protection and ensure the stability of the high-side power switch in the power-on process, time delay protection is designed in the short-circuit or overload protection circuit, namely when the voltage or current in the high-side power switch meets the short-circuit or overload protection condition, the short-circuit or overload protection circuit does not immediately take protection action but keeps the working state for a period of time to start the protection function, and the power switch is damaged due to short circuit or overload current, so that the stability of the high-side power switch is challenged.
Disclosure of Invention
The invention provides a current-limiting protection method for a high-side power switch, which is used for solving the technical problem that the stability of the high-side power switch in the prior art is not high when the time-delay protection mode is adopted, and comprises the following steps:
generating a trigger signal according to a sampling parameter, wherein the sampling parameter is sampling current or sampling voltage;
discharging a gate charge of a main power transistor of the high-side power switch based on the trigger signal;
wherein the sampled current is indicative of a current flowing through the main power tube, and the sampled voltage is indicative of a voltage applied to the main power tube.
Preferably, discharging the gate charge of the main power transistor of the high-side power switch based on the trigger signal specifically includes:
receiving the trigger signal;
and turning on a turn-on circuit connected with the grid electrode of the main power tube based on the trigger signal so as to discharge the grid electrode charge.
Preferably, before generating the trigger signal according to the sampling parameter, the method further includes:
generating the sampling current based on the current of the main power tube, and taking the sampling current as the sampling parameter;
or the like, or, alternatively,
and generating the sampling voltage based on the voltage of the main power tube, and taking the sampling voltage as the sampling parameter.
Preferably, the trigger signal is a high level signal or a low level signal, and a turn-on circuit connected to the gate of the main power transistor is turned on based on the trigger signal, specifically:
when the trigger signal is a high level signal, the conducting circuit is conducted based on the high level signal;
and when the trigger signal is a low level signal, the conducting circuit is conducted based on the low level signal.
Preferably, the sampling current is in direct proportion or inverse proportion to the current of the main power tube, and the sampling voltage is in direct proportion or inverse proportion to the voltage of the main power tube.
Correspondingly, the invention also provides a current-limiting protection circuit for the high-side power switch, which comprises a main power tube and further comprises:
the signal generating circuit is used for sensing sampling parameters and outputting a trigger signal to the conducting circuit according to the sampling parameters, wherein the sampling parameters are sampling current or sampling voltage;
the conducting circuit is used for discharging grid charges of the main power tube according to the trigger signal;
wherein the sampled current is indicative of a current flowing through the main power tube, and the sampled voltage is indicative of a voltage applied to the main power tube.
Preferably, the signal generating circuit is connected with the main power tube, or the signal generating circuit is connected with a sampling circuit of the main power tube.
Preferably, the conduction circuit is any one or any combination of circuits or devices that conduct according to the trigger signal and discharge the gate charge.
Preferably, the conduction circuit includes a switching tube or a power tube.
Preferably, the signal generating circuit is a circuit or a component capable of generating any one or any combination of the trigger signals according to the sensed sampling parameters.
Compared with the prior art, the invention has the following beneficial effects:
the invention discloses a current-limiting protection method and a circuit for a high-side power switch, wherein the method comprises the following steps: generating a trigger signal according to a sampling parameter, wherein the sampling parameter is sampling current or sampling voltage; discharging a gate charge of a main power transistor of the high-side power switch based on the trigger signal; the sampling current is the current which is characterized to flow through the main power tube, and the sampling voltage is the voltage which is characterized to be applied to the main power tube, so that when the parameters in the high-side power switch meet the short-circuit or overload protection condition, the grid voltage of the main power tube is reduced relative to the drain voltage VGS, the current value flowing through the main power tube is reduced, the main power tube is prevented from being damaged due to delay protection during short-circuit or overload, and the stability and the reliability of the high-side power switch are further improved.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
Fig. 1 is a schematic flow chart illustrating a current limiting protection method for a high-side power switch according to an embodiment of the present invention;
fig. 2 is a schematic diagram illustrating a current limiting protection circuit for a high-side power switch according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of a signal generating circuit according to an embodiment of the present invention;
FIG. 4 is a schematic diagram showing the structure of another signal generating circuit according to the embodiment of the present invention;
fig. 5 is a schematic diagram illustrating a current limiting protection circuit for a high-side power switch according to another embodiment of the present invention;
fig. 6 shows a schematic structural diagram of a turn-on circuit in an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
As described in the background art, in order to implement short circuit or overload protection and ensure the stability of the high-side power switch during power-on process in the prior art, a time delay protection is designed in a short circuit or overload protection circuit, that is, when the voltage or current in the high-side power switch meets the short circuit or overload protection condition, the short circuit or overload protection circuit does not immediately take a protection action but keeps working for a period of time before starting a protection function, and the time delay protection mode can damage the power switch due to short circuit or overload current, so that the stability of the high-side power switch is affected.
In order to solve the above problem, an embodiment of the present application provides a current limiting protection method for a high-side power switch, as shown in fig. 1, including the following steps:
step S101: and generating a trigger signal according to a sampling parameter, wherein the sampling parameter is sampling current or sampling voltage. Wherein the sampling current is a current representing the current flowing through the main power tube, and the sampling voltage is a voltage representing the voltage applied to the main power tube end.
Specifically, in order to ensure the power-on stability of the high-side power switch and avoid triggering short circuit or overload protection due to the fact that the difference value between the power supply voltage and the source voltage of the main power tube exceeds a preset voltage difference range in the power-on process, short circuit or overload protection time delay is designed in the circuit. When the high-voltage power switch is short-circuited, the current or voltage of the main power tube rises, and if the protection action cannot be timely performed or the voltage or current of the end of the main power tube cannot be reduced, the main power tube can be burnt or damaged due to temperature rise, so that the power switch cannot normally work, and the stability and reliability of the whole system are affected. Therefore, when the high-side power switch is ensured to be electrified stably, and the high-side power switch is ensured not to be damaged due to short circuit or overload in the normal working process, current-limiting protection is required, namely, the current or the voltage of the main power switch is acquired, the acquired sampling parameters are compared with corresponding preset parameter thresholds, and a trigger signal is generated according to the comparison result, so that the grid charge of the main power tube is discharged, and the current-limiting protection is realized.
In order to ensure the sampling accuracy of the high-side power switch, in a preferred embodiment of the present application, before generating the trigger signal according to the sampling parameter, the method further includes:
generating the sampling current based on the current of the main power tube, and taking the sampling current as the sampling parameter;
or the like, or, alternatively,
and generating the sampling voltage based on the voltage of the main power tube, and taking the sampling voltage as the sampling parameter.
Specifically, in order to ensure the sampling accuracy of the high-side power switch in the short-circuit or overload protection process, the sampling current which is collected and represents the current of the main power tube can be used as the sampling parameter, and the sampling voltage which is collected and represents the voltage of the main power tube can also be used as the sampling parameter.
It should be noted that the above solution of the preferred embodiment is only a specific implementation solution provided by the present application, and a person skilled in the art can flexibly select different signal acquisition manners in the case of short circuit or overload occurring in the high-side power open tube according to actual conditions, for example, a trigger signal can be generated by acquiring a power change of the main power tube, when a short circuit or overload occurs, the power of the main power tube changes, and the trigger signal is generated according to a comparison result by comparing the acquired power of the main power tube with a preset power value; or judging according to the power, current or voltage variation trend of the main power tube, judging whether the high-side power switch is short-circuited or overloaded, and if the high-side power switch is short-circuited or overloaded, discharging the grid current of the main power switch through an external circuit or performing creative design on an original control circuit.
For the sampling current or the sampling voltage, in the preferred embodiment of the present application, the sampling current is in a direct proportion or inverse proportion relation with the current of the main power tube, and the sampling voltage is in a direct proportion or inverse proportion relation with the voltage of the main power tube.
Specifically, in order to accurately determine the operating state of the high-side power switch, the current or voltage flowing through the main power transistor needs to be collected. Therefore, the sampling current or the sampling voltage can be directly collected at the end of the main power tube and has a 1:1 relation with the current or the voltage of the main power tube, or can be derived from a sampling circuit connected with the main power tube, and the current or the voltage of the sampling circuit is in a direct proportion or inverse proportion relation with the current or the voltage of the main power tube.
Step S102: discharging a gate charge of a main power transistor of the high-side power switch based on the trigger signal.
Specifically, when the high-side power switch is short-circuited or overloaded, the source of the main power tube is grounded, and the gate voltage of the main power tube is increased relative to the source voltage VGS, so that the current flowing through the main power tube is increased, and the main power tube is damaged due to overcurrent. Therefore, when the sampling current or the sampling voltage rises to a certain value and is greater than the corresponding preset parameter threshold value, a trigger signal is output to discharge the grid charge of the main power tube; or when the sampling current or the sampling voltage rises to a certain value and is smaller than the preset parameter threshold, outputting a trigger signal to discharge the gate charge of the main power tube, in a specific application scenario of the present application, referring to fig. 3, a schematic structural diagram of a signal generating circuit in an embodiment of the present invention is shown, a positive input end a of a comparator com1 is used for sensing a sampling parameter (e.g., sampling current CS), an output end is connected to a conducting circuit, and when the sampling parameter is larger than the corresponding preset parameter threshold (e.g., current value), outputting a trigger signal which is a high level signal to the conducting circuit to conduct the conducting circuit, thereby realizing the gate charge discharge of the main power tube M1 and reducing the current flowing through the main power tube M1. Fig. 4 shows a schematic structural diagram of another signal generating circuit according to an embodiment of the present invention, in which an inverting input terminal B of the comparator com1 is used for sensing a sampling parameter (e.g., sampling current CS), and an output terminal thereof is connected to the conducting circuit, and when the sampling parameter is smaller than a corresponding preset parameter threshold (e.g., current value), a trigger signal which is a low-level signal is output to the conducting circuit to conduct the conducting circuit, so as to discharge gate charges of the main power transistor M1 and reduce current flowing through the main power transistor M1.
In order to implement main power tube gate charge draining, in a preferred embodiment of the present application, the draining of the gate charge of the main power tube of the high-side power switch based on the trigger signal specifically includes:
receiving the trigger signal;
and turning on a turn-on circuit connected with the grid electrode of the main power tube based on the trigger signal so as to discharge the grid electrode charge.
Specifically, when the high-side power switch normally works, the difference between the gate voltage of the main power tube relative to the source voltage VGS and the starting voltage VTh is greater than the drain voltage of the main power tube relative to the source voltage VDS, the sampling parameter cannot reach the condition of forming the trigger signal, the high-side power switch conduction circuit is turned off, and the gate charge of the main power switch cannot be discharged.
When short circuit or overload occurs, the difference value between the grid voltage of the main power tube relative to the source voltage VGS and the starting voltage VTh is larger than the drain voltage of the main power tube relative to the source voltage VDS, the sampling parameter is larger than the preset parameter threshold value, or the sampling parameter is smaller than the preset parameter threshold value, the high-side power switch signal generating circuit outputs a trigger signal, so that a conducting circuit connected with the grid of the main power tube is conducted, the grid charge of the main power tube is discharged, and the current-limiting protection of the high-side power switch is realized.
For the on-circuit control, in the preferred embodiment of the present application,
the trigger signal is a high level signal or a low level signal, and a conduction circuit connected with the grid electrode of the main power tube is conducted based on the trigger signal, specifically:
when the trigger signal is a high level signal, the conducting circuit is conducted based on the high level signal;
and when the trigger signal is a low level signal, the conducting circuit is conducted based on the low level signal.
Specifically, the conduction circuit disclosed by the disclosure is mainly controlled by a trigger signal, and when the trigger signal is at a high level, a circuit or a component which is conducted by receiving the high-level signal can be selected; when the trigger signal is at low level, the circuit or the component which is conducted by receiving the low level signal can be selected, and both the two modes can realize that the conducting circuit is conducted according to the trigger signal, so that the charge discharge of the grid electrode of the main power tube is realized.
By applying the technical scheme, when the high-side power switch works in a short-circuit or overload delay protection state and parameters in the high-side power switch meet short-circuit or overload protection conditions, a trigger signal is generated according to sampling parameters, wherein the sampling parameters are sampling current or sampling voltage; discharging a gate charge of a main power transistor of the high-side power switch based on the trigger signal; the sampling current is the current which is characterized to flow through the main power tube, the sampling voltage is the voltage which is characterized to be applied to the main power tube, the grid voltage of the main power tube is reduced relative to the drain voltage VGS of the main power tube, the current value which flows through the main power tube is reduced, the main power tube is prevented from being damaged due to time delay protection when the main power tube is in short circuit or overload, and therefore the stability and the reliability of the high-side power switch are improved.
In order to further illustrate the technical idea of the present invention, the technical solution of the present invention will now be described with reference to specific application scenarios.
The circuit corresponding to the current-limiting protection method for the high-side power switch is provided with a signal generating circuit connected with the main power tube, wherein the signal generating circuit is used for sensing sampling parameters and outputting a trigger signal to a conducting circuit according to the sampling parameters; the conducting circuit is used for discharging grid charges of the main power tube according to the trigger signal, so that the stability and the reliability of the high-side power switch are improved.
The principle of the current-limiting protection method for the high-side power switch in the embodiment of the invention is as follows:
the method comprises the steps of firstly, collecting current or voltage of a main power tube of a high-side power switch to generate sampling parameters, wherein the sampling parameters are sampling current or sampling voltage;
secondly, comparing the sampling parameter with a preset current or a preset voltage, and generating a trigger signal according to a comparison result;
and thirdly, conducting a conducting circuit connected with the grid electrode of the main power tube according to a trigger signal so as to discharge the grid electrode charge of the main power tube.
Fig. 2 is a schematic structural diagram of a current-limiting protection circuit for a high-side power switch according to an embodiment of the present invention, in which a signal generating circuit senses a sampling current CS and outputs a trigger signal to a conducting circuit according to the sampling current CS; or the signal generating circuit senses the sampling voltage and outputs a trigger signal to the conducting circuit according to the sampling voltage; the conducting circuit is conducted according to the received trigger signal, so that grid charges of the main power tube M1 are discharged, and therefore when the high-side power switch is in short circuit or overload and enters time-delay protection, the current flowing through the main power tube M1 is reduced, and the reliability and the stability of the high-side power switch are improved.
For the signal generating circuit, it is mainly used for sensing sampling parameters, the sampling parameters may be sampling current CS, sampling voltage or sampling power corresponding to the main power tube M1, and outputs a trigger signal to the conducting circuit according to the sampling parameters. Referring to fig. 3, which shows a schematic structural diagram of a signal generating circuit in an embodiment of the present invention, a positive input end a of the comparator com1 is used for sensing a sampling parameter (e.g., a sampling current CS), and an output end is connected to the conducting circuit, and when the sampling parameter is greater than a corresponding preset parameter threshold (e.g., a current value), a trigger signal that is a high-level signal is output to the conducting circuit to conduct the conducting circuit, so as to implement gate charge draining of the main power transistor M1 and reduce a current flowing through the main power transistor M1.
Fig. 4 shows a schematic structural diagram of another signal generating circuit according to an embodiment of the present invention, in which an inverting input terminal B of the comparator com1 is used for sensing a sampling parameter (e.g., sampling current CS), and an output terminal thereof is connected to the conducting circuit, and when the sampling parameter is smaller than a corresponding preset parameter threshold (e.g., current value), a trigger signal which is a low-level signal is output to the conducting circuit to conduct the conducting circuit, so as to discharge gate charges of the main power transistor M1 and reduce current flowing through the main power transistor M1.
Fig. 5 is a schematic structural diagram of a current-limiting protection circuit for a high-side power switch according to another embodiment of the present invention, in which a signal generation circuit senses a sampling current CS through a single-chip ADC, and outputs N digital trigger signals to a conduction circuit according to a value of the sampling current CS, so as to control the conduction times of the conduction circuit and implement current control on a main power transistor M1.
The signal generating circuit senses the sampling parameters and outputs trigger signals to the conducting circuit according to the sampling parameters so as to realize the control of the conducting circuit, and the conducting circuit is conducted based on the trigger signals so as to discharge the grid charges of the main power tube M1.
Referring to fig. 6, the turn-on circuit includes a switch M3, and when the received trigger signal is at a high level, the switch M3 is turned on, so that the gate of the main power transistor M1 is grounded, and the charge discharge of the gate of the main power transistor M1 is realized.
Referring to the conduction circuit in fig. 5, another conduction circuit structure is shown, the conduction circuit includes a plurality of switching tubes Mn1-Mnn, and as the sampling current CS sensed by the signal generating circuit increases, the number of the switching tubes Mn connected to the gate of the main power tube M1 is increased, that is, a plurality of the switching tubes Mn are turned on, so as to discharge the charge of the main power tube M1.
Referring to fig. 4, the turn-on circuit includes a P-type power transistor M4, when the comparator com1 outputs a low level signal, the power switch M4 is turned on, so that the gate of the main power transistor M1 is grounded, and the charge discharge of the gate of the main power transistor M1 is realized.
The turn-on circuit may be turned on according to a trigger signal received as a high level signal or a low level signal, so as to discharge the gate charge of the main power transistor M1.
The signal generating circuit can sense and represent the current or voltage or power flowing through the main power tube M1, so that the signal generating circuit can be directly connected with the main power tube M1 to acquire sampling parameters required for generating the trigger signal; in addition, the signal generating circuit may be further connected to a sampling circuit of the main power tube MI, as shown in fig. 2, the signal generating current may be connected to the sampling tube M2 to collect sampling parameters, because the sampling parameters output by the sampling circuit of the main power tube M1 reflect corresponding proportional parameters on the main power tube M1, and may represent the current or voltage or power flowing through the main power tube M1.
In the above process, the signal generating circuit is connected to the sampling circuit of the main power tube M1 or the main power tube M1, collects the sampling parameters, and generates the trigger signal which is a high level signal or a low level signal according to the sampling parameters to the conducting circuit connected to the gate of the main power tube M1, so that the conducting circuit is conducted according to the trigger signal, and the gate of the main power tube M1 is grounded, thereby discharging the charges.
In order to achieve the above technical object, an embodiment of the present application further provides a current limiting protection circuit for a high-side power switch, including a main power transistor, further including:
the signal generating circuit is used for sensing sampling parameters and outputting a trigger signal to the conducting circuit according to the sampling parameters, wherein the sampling parameters are sampling current or sampling voltage;
the conducting circuit is used for discharging grid charges of the main power tube according to the trigger signal;
wherein the sampled current is indicative of a current flowing through the main power tube, and the sampled voltage is indicative of a voltage applied to the main power tube.
Specifically, when the high-side power switch is short-circuited or overloaded, the signal generating circuit generates a trigger signal to the conducting circuit according to the sensed sampling parameter, and the conducting circuit is conducted according to the received trigger signal, so that the charge discharge of the grid electrode of the main power tube is realized.
In order to achieve the accuracy of control, in a preferred embodiment of the present application, the signal generating circuit is connected to the main power tube, or the signal generating circuit is connected to a sampling circuit of the main power tube.
Specifically, for the connection mode of the signal generating circuit and the main power tube, the current or voltage or power flowing through the main power tube can be directly collected, and the signal generating circuit can also be connected with the sampling circuit of the main power tube, so that the accuracy of information extraction is improved.
In a preferred embodiment of the present invention, the conducting circuit is a circuit or a component that conducts according to the trigger signal and discharges the gate charge, or any combination of the circuits.
Specifically, the on circuit is mainly used to discharge the charge on the gate of the main power transistor by turning on the main power transistor according to the trigger signal, and therefore, the on circuit can be used for any device or circuit capable of achieving the function.
For the conducting circuit, in the preferred embodiment of the present application, the conducting circuit includes a switching tube or a power tube.
For the signal generating circuit, in the preferred embodiment of the present application, the signal generating circuit is a circuit or a component capable of generating any one or any combination of the trigger signals according to the sensed sampling parameter.
Specifically, the signal generating circuit is used for sensing a sampling parameter and outputting a trigger signal to the conducting circuit according to the sampling parameter, so that the signal generating circuit can be used for components or circuits capable of achieving the function.
By applying the technical scheme, the signal generating circuit is used for sensing sampling parameters and outputting a trigger signal to the conducting circuit according to the sampling parameters, wherein the sampling parameters are sampling current or sampling voltage; the conducting circuit is used for discharging grid charges of the main power tube according to the trigger signal, wherein the sampling current is used for representing the current flowing through the main power tube, and the sampling voltage is used for representing the voltage applied to the main power tube, so that the stability and the reliability of the high-side power switch are improved.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not necessarily depart from the spirit and scope of the corresponding technical solutions in the embodiments of the present application.
Claims (10)
1. A method of current limiting protection for a high side power switch, the method comprising:
generating a trigger signal according to a sampling parameter, wherein the sampling parameter is sampling current or sampling voltage;
discharging a gate charge of a main power transistor of the high-side power switch based on the trigger signal;
wherein the sampled current is indicative of a current flowing through the main power tube, and the sampled voltage is indicative of a voltage applied to the main power tube.
2. The method of claim 1, wherein discharging the gate charge of a main power transistor of the high-side power switch based on the trigger signal comprises:
receiving the trigger signal;
and turning on a turn-on circuit connected with the grid electrode of the main power tube based on the trigger signal so as to discharge the grid electrode charge.
3. The method of claim 1, prior to generating the trigger signal according to the sampling parameter, further comprising:
generating the sampling current based on the current of the main power tube, and taking the sampling current as the sampling parameter;
or the like, or, alternatively,
and generating the sampling voltage based on the voltage of the main power tube, and taking the sampling voltage as the sampling parameter.
4. The method according to claim 2, wherein the trigger signal is a high level signal or a low level signal, and a turn-on circuit connected to the gate of the main power transistor is turned on based on the trigger signal, specifically:
when the trigger signal is a high level signal, the conducting circuit is conducted based on the high level signal;
and when the trigger signal is a low level signal, the conducting circuit is conducted based on the low level signal.
5. The method of claim 1 or 3, wherein the sampled current is directly or inversely proportional to the current of the main power tube, and the sampled voltage is directly or inversely proportional to the voltage of the main power tube.
6. A current-limiting protection circuit for a high-side power switch, comprising a main power transistor, further comprising:
the signal generating circuit is used for sensing sampling parameters and outputting a trigger signal to the conducting circuit according to the sampling parameters, wherein the sampling parameters are sampling current or sampling voltage;
the conducting circuit is used for discharging grid charges of the main power tube according to the trigger signal;
wherein the sampled current is indicative of a current flowing through the main power tube, and the sampled voltage is indicative of a voltage applied to the main power tube.
7. The current-limiting protection circuit for a high-side power switch of claim 6, wherein the signal generating circuit is connected to the main power transistor or the signal generating circuit is connected to a sampling circuit of the main power transistor.
8. The current-limiting protection circuit for a high-side power switch of claim 6, wherein the turn-on circuit is any one or any combination of a circuit or a component that turns on and discharges the gate charge according to the trigger signal.
9. The current-limiting protection circuit for a high-side power switch of claim 8, wherein the turn-on circuit comprises a switch tube or a power tube.
10. The current-limiting protection circuit for a high-side power switch of claim 6, wherein the signal generating circuit is any one or any combination of circuits or components capable of generating the trigger signal based on sensing the sampling parameter.
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| CN (1) | CN111342647A (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111864701A (en) * | 2020-07-27 | 2020-10-30 | 深圳青铜剑技术有限公司 | Reference voltage generating circuit and method for IGBT short-circuit protection |
| CN113054975A (en) * | 2021-03-31 | 2021-06-29 | 中国科学院微电子研究所 | Low-side power switch integrated module and driving chip |
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| US20080030174A1 (en) * | 2006-08-01 | 2008-02-07 | Kenichi Niiyama | Load driving circuit and protection method |
| CN101409545A (en) * | 2008-11-13 | 2009-04-15 | 何岳明 | Overload protection circuit for switch type transistor |
| CN105048422A (en) * | 2015-09-02 | 2015-11-11 | 何岳明 | Switch transistor voltage drop holding circuit and application of switch transistor voltage drop holding circuit in lithium battery protection circuit |
| CN105577152A (en) * | 2016-01-07 | 2016-05-11 | 圣邦微电子（北京）股份有限公司 | Protection circuit in load switch |
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| US20080030174A1 (en) * | 2006-08-01 | 2008-02-07 | Kenichi Niiyama | Load driving circuit and protection method |
| CN101087103A (en) * | 2007-04-13 | 2007-12-12 | 珠海格力电器股份有限公司 | Method of DC power device for improving power factor and adjusting output voltage |
| CN101409545A (en) * | 2008-11-13 | 2009-04-15 | 何岳明 | Overload protection circuit for switch type transistor |
| CN105048422A (en) * | 2015-09-02 | 2015-11-11 | 何岳明 | Switch transistor voltage drop holding circuit and application of switch transistor voltage drop holding circuit in lithium battery protection circuit |
| CN105577152A (en) * | 2016-01-07 | 2016-05-11 | 圣邦微电子（北京）股份有限公司 | Protection circuit in load switch |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111864701A (en) * | 2020-07-27 | 2020-10-30 | 深圳青铜剑技术有限公司 | Reference voltage generating circuit and method for IGBT short-circuit protection |
| CN111864701B (en) * | 2020-07-27 | 2023-03-21 | 深圳青铜剑技术有限公司 | Reference voltage generating circuit and method for IGBT short-circuit protection |
| CN113054975A (en) * | 2021-03-31 | 2021-06-29 | 中国科学院微电子研究所 | Low-side power switch integrated module and driving chip |
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