CN114597864A - Power supply protection circuit and circuit system - Google Patents
Power supply protection circuit and circuit system Download PDFInfo
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- CN114597864A CN114597864A CN202011394771.5A CN202011394771A CN114597864A CN 114597864 A CN114597864 A CN 114597864A CN 202011394771 A CN202011394771 A CN 202011394771A CN 114597864 A CN114597864 A CN 114597864A
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/10—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers
- H02H7/12—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers
- H02H7/1213—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers for DC-DC converters
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Abstract
The application provides a power protection circuit and circuitry, this power protection circuit includes: overcurrent protection circuit, overvoltage crowbar and two kinds of at least circuits of undervoltage crowbar, power protection circuit still includes: the output of the level signal conversion circuit is connected with load equipment through the control switch; the over-current protection circuit is used for performing over-current detection on the power supply and outputting a first output signal, the over-voltage protection circuit is used for performing over-voltage detection on the power supply and outputting a second output signal, and the under-voltage protection circuit is used for performing under-voltage detection on the power supply and outputting a third output signal; the level signal conversion circuit is used for controlling the control switch according to the first output signal, the second output signal and the third output signal so as to control the on-off between the load equipment and the power supply. The working reliability, the stability and the applicability of the power circuit are improved.
Description
Technical Field
The application relates to the technical field of power protection, in particular to a power protection circuit and a circuit system.
Background
Some unstable factors often exist in the power supply circuit, which can directly or indirectly cause the power supply of the power supply circuit to be abnormal, so that the load equipment works abnormally, and even the whole circuit system is paralyzed. Therefore, when designing an electronic product, a power protection circuit is usually designed on a power circuit to prevent a circuit system from malfunctioning due to various unstable factors.
Faults which may occur in the power supply circuit mainly include overcurrent, undervoltage, overvoltage and the like. In the prior art, in order to ensure that a power supply circuit can operate safely and reliably, corresponding protection schemes (overcurrent protection, overvoltage protection, undervoltage protection and the like) are usually designed separately, for example, a current detection chip or a voltage detection chip and the like are used for monitoring the current or the voltage of the power supply circuit so as to monitor the working condition of the power supply circuit, find a fault in time and cut off the power supply of a fault device, thereby preventing the accident from expanding.
However, in the prior art, each power protection scheme has a single protection function, and the reliability of the power circuit is low.
Disclosure of Invention
The application provides a power supply protection circuit and a circuit system to realize the comprehensive protection of a power supply circuit and improve the reliability of the power supply circuit.
In a first aspect, an embodiment of the present application provides a power protection circuit, including:
the power supply protection circuit comprises at least two circuits of an overcurrent protection circuit, an overvoltage protection circuit and an undervoltage protection circuit, and further comprises a level signal conversion circuit and a control switch;
the input end of the overcurrent protection circuit, the input end of the overvoltage protection circuit and the input end of the undervoltage protection circuit are respectively connected with a power supply, the output end of the overcurrent protection circuit, the output end of the overvoltage protection circuit and the output end of the undervoltage protection circuit are respectively connected with the input of the level signal conversion circuit, and the output of the level signal conversion circuit is connected with load equipment through a control switch;
the over-current protection circuit is used for performing over-current detection on the power supply and outputting a first output signal, the over-voltage protection circuit is used for performing over-voltage detection on the power supply and outputting a second output signal, and the under-voltage protection circuit is used for performing under-voltage detection on the power supply and outputting a third output signal;
the level signal conversion circuit is used for controlling the control switch according to the first output signal, the second output signal and the third output signal so as to control the on-off between the load equipment and the power supply.
In the embodiment of the application, through set up overcurrent protection circuit in power protection circuit, overvoltage crowbar and undervoltage protection circuit, can realize the overcurrent detection to the power respectively, overvoltage detection and undervoltage detection, and, according to overcurrent detection, overvoltage crowbar and undervoltage detection's output signal through level signal converting circuit, control switch, power protection circuit can have overcurrent protection function simultaneously, overvoltage crowbar and undervoltage protection function, power protection circuit's operational reliability and stability have been improved, and can also realize freely switching and selecting of each protect function through level signal converting circuit and accept or reject, power protection circuit's suitability has been improved.
In one possible embodiment, the overcurrent protection circuit includes: a first amplifying circuit and a first resistor;
the first end of the first resistor is connected with the power supply, and the second end of the first resistor is connected with the control switch; the first input end of the first amplifying circuit is connected with the first end of the first resistor, the second input end of the first amplifying circuit is connected with the second end of the first resistor, and the first amplifying circuit is used for amplifying the voltage on the first resistor to generate and output a first output signal.
In the embodiment of the application, the current in the power circuit is detected by detecting the voltage on the first resistor, and the voltage on the first resistor is amplified by the amplifying circuit, so that the reliability of the first output signal can be improved.
In one possible implementation, the first amplification circuit includes: the operational amplifier is connected with the first resistor, the second resistor, the third resistor, the fourth resistor, the fifth resistor and the operational amplifier;
one end of the second resistor is grounded, the other end of the second resistor is connected with a fourth resistor, the fourth resistor is connected with the first end of the first resistor, one end of the third resistor is connected with a fifth resistor, the other end of the third resistor is connected with the output end of the operational amplifier, the fifth resistor is connected with the second end of the first resistor, and the other end of the third resistor is connected with the output end of the operational amplifier; the first input end of the operational amplifier is connected between the second resistor and the fourth resistor, and the second input end of the operational amplifier is connected between the third resistor and the fifth resistor.
In one possible embodiment, the under-voltage protection circuit includes: a first voltage dividing circuit and a first switching circuit;
the first voltage division circuit comprises a seventh resistor and at least one eighth resistor, one end of the seventh resistor is connected with the eighth resistor in series, the other end of the seventh resistor is grounded, and the eighth resistor is connected with a power supply; one end of the first switch circuit is connected between the seventh resistor and the eighth resistor, and the other end of the first switch circuit is connected with the level signal conversion circuit and used for outputting a third output signal to the level signal conversion circuit.
In one possible embodiment, the first switching circuit includes: one end of the ninth resistor is connected between the seventh resistor and the eighth resistor, the other end of the ninth resistor is connected with the grid electrode of the first NMOS, the source electrode of the first NMOS is grounded, and the drain electrode of the first NMOS is connected with the level signal conversion circuit; the first NMOS is configured to output a high level signal to the level signal conversion circuit when the voltage across the seventh resistor is less than a predetermined voltage.
In a possible implementation manner, the number of the eighth resistors is plural, and the plural eighth resistors are connected in series, and the undervoltage protection circuit further includes: a feedback loop compensation circuit; the feedback loop compensation circuit comprises a tenth resistor and a PMOS, wherein the source electrode of the PMOS is connected between the power supply and the tenth resistor, the grid electrode of the PMOS is connected between the tenth resistor and the level signal conversion circuit, and the drain electrode of the PMOS is connected between the eighth resistors.
In one possible embodiment, the overvoltage protection circuit includes: a second voltage dividing circuit and a comparator;
the second voltage division circuit comprises a twelfth resistor and a thirteenth resistor, the twelfth resistor is connected with the thirteenth resistor in series, the twelfth resistor is connected with the power supply, and the thirteenth resistor is grounded; a first input end of the comparator is connected between the twelfth resistor and the thirteenth resistor, a second input end of the comparator is connected between the seventh resistor and the eighth resistor, and an output end of the comparator is connected with the level signal conversion circuit; the comparator is used for outputting a second output signal to the level signal conversion circuit.
In one possible embodiment, at least one of the over-current protection circuit, the over-voltage protection circuit, and the under-voltage protection circuit includes a sequential circuit;
the time sequence circuit is used for filtering and delaying a first output signal of the overcurrent protection circuit; and/or
The time sequence circuit is used for filtering and delaying a second output signal of the overvoltage protection circuit; and/or
And the time sequence circuit is used for filtering and delaying the third output signal of the undervoltage protection circuit.
In one possible implementation, the timing circuit includes a sixth resistor and a first capacitor; one end of a sixth resistor is connected with the output end of the operational amplifier, the other end of the sixth resistor is respectively connected with the first capacitor and the level signal conversion circuit, and the first capacitor is grounded; and/or
The sequential circuit comprises an eleventh resistor and a second capacitor; one end of an eleventh resistor is connected with the drain electrode of the first NMOS, the other end of the eleventh resistor is respectively connected with the second capacitor and the level signal conversion circuit, and the second capacitor is grounded; and/or the timing circuit comprises a fourteenth resistor and a third capacitor; one end of the fourteenth resistor is connected with the output end of the comparator, the other end of the fourteenth resistor is respectively connected with the third capacitor and the level signal conversion circuit, and the third capacitor is grounded.
In the embodiment of the application, the filtering and the time delay of the output signal are realized by arranging the sequential circuit in at least one of the over-current protection circuit/the over-voltage protection circuit and the under-voltage protection circuit.
In one possible implementation, the level signal conversion circuit includes a first diode, a second diode, a third diode, a first transistor and a second transistor,
the anode of the first diode is connected with the output end of the over-current protection circuit, the anode of the second diode is connected with the output end of the under-voltage protection circuit, and the anode of the third diode is connected with the output end of the over-voltage protection circuit; the cathode of the first diode, the cathode of the second diode and the cathode of the third diode are respectively connected with the base of the first triode and the base of the second triode, the emitting electrode of the first triode is connected with the power supply, the emitting electrode of the second triode is grounded, and the collecting electrode of the first triode and the collecting electrode of the second triode are connected with the control switch.
In one possible embodiment, the control switch comprises: the second NMOS is a second NMOS,
the grid electrode of the second NMOS, the collector electrode of the first triode and the collector electrode of the second triode are connected, the source electrode of the second NMOS is connected with the power supply, and the drain electrode of the second NMOS is connected with the control switch.
In one possible embodiment, the control switch further comprises: the third NMOS is a second NMOS,
the grid electrode of the third NMOS, the collector electrode of the first triode and the collector electrode of the second triode are connected, the source electrode of the third NMOS is connected with load equipment, and the drain electrode of the third NMOS is connected with the drain electrode of the second NMOS.
In one possible implementation, the level signal conversion circuit includes a control chip,
a first pin of the control chip is connected with the output end of the overcurrent protection circuit, a second pin of the control chip is connected with the output end of the undervoltage protection circuit, and a third pin of the control chip is connected with the output end of the overvoltage protection circuit; and a fourth pin of the control chip is connected with the control switch.
In a second aspect, an embodiment of the present application provides a circuit system, including: a power supply, a load device and a power supply protection circuit as described in the first aspect and alternatives to the first aspect.
According to the power supply protection circuit and the circuit system, the input end of the overcurrent protection circuit, the input end of the overvoltage protection circuit and the input end of the undervoltage protection circuit are respectively connected with a power supply, the output end of the overcurrent protection circuit, the output end of the overvoltage protection circuit and the output end of the undervoltage protection circuit are respectively connected with the input of the level signal conversion circuit, and the output of the level signal conversion circuit is connected with load equipment through the control switch; the over-current protection circuit is used for performing over-current detection on the power supply and outputting a first output signal, the over-voltage protection circuit is used for performing over-voltage detection on the power supply and outputting a second output signal, and the under-voltage protection circuit is used for performing under-voltage detection on the power supply and outputting a third output signal; the level signal conversion circuit is used for controlling the control switch according to the first output signal, the second output signal and the third output signal so as to control the on-off between the load equipment and the power supply. In the embodiment of the application, because the overcurrent protection circuit is arranged in the power protection circuit, at least two kinds of circuits in the overvoltage protection circuit and the undervoltage protection circuit, at least two kinds of detection functions in overcurrent detection, overvoltage detection and undervoltage detection of the power supply can be realized, and the control switch is controlled according to output signals of overcurrent detection, overvoltage detection and undervoltage detection through the level signal conversion circuit, the power protection circuit can simultaneously have the overcurrent protection function, at least two kinds of functions in the overvoltage protection function and the undervoltage protection function, the working reliability and stability of the power supply circuit are improved, free switching and selective accepting and rejecting of each protection function can also be realized through the level signal conversion circuit, and the applicability of the power protection circuit is improved.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive exercise.
FIG. 1 is an exemplary application scenario architecture diagram provided by an embodiment of the present application;
fig. 2 is a schematic structural diagram of a power protection circuit according to an embodiment of the present application;
fig. 3 is a schematic structural diagram of an overcurrent protection circuit according to an embodiment of the application;
FIG. 4 is a schematic diagram of an under-voltage protection circuit according to an embodiment of the present application;
fig. 5 is a schematic structural diagram of an under-voltage protection circuit according to another embodiment of the present application;
fig. 6 is a schematic structural diagram of an overvoltage protection circuit according to an embodiment of the present application;
fig. 7 is a schematic structural diagram of an overvoltage protection circuit according to another embodiment of the present application;
fig. 8 is a schematic structural diagram of a level signal conversion circuit according to an embodiment of the present application;
fig. 9 is a schematic structural diagram of a control switch according to an embodiment of the present application;
fig. 10 is a schematic structural diagram of a power protection circuit according to yet another embodiment of the present application.
Description of reference numerals:
11: a first amplifying circuit;
12: a sequential circuit;
VCC: a power source;
u1: an operational amplifier;
r1: a first resistor;
r2: a second resistor;
r3: a third resistor;
r4: a fourth resistor;
r5: a fifth resistor;
r6: a sixth resistor;
21: a first voltage dividing circuit;
22: a first switching circuit;
r7: a seventh resistor;
r8: an eighth resistor;
r9: a ninth resistor;
q1: a first NMOS;
23: a feedback loop compensation circuit;
24: a sequential circuit;
r10: a tenth resistor;
Q2：PMOS；
r11: an eleventh resistor;
c2: a second capacitor;
31: a second voltage dividing circuit;
u2: a comparator;
r12: a twelfth resistor;
r13: a thirteenth resistance;
32: a sequential circuit;
r14: a fourteenth resistance;
c3: a third capacitor;
d1: a first diode;
d2: a second diode;
d3: a third diode;
q3: a first triode;
q4: a second triode;
r15: a fifteenth resistor;
q5: a second NMOS;
q6: and a third NMOS.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, 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 some embodiments of the present application, but not all 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.
The terms "first," "second," "third," "fourth," and the like in the description and in the claims of the present application and in the drawings described above, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
Some unstable factors often exist in the power supply circuit, which can directly or indirectly cause the power supply of the power supply circuit to be abnormal, so that the load equipment works abnormally, and even the whole circuit system is paralyzed. Therefore, when designing an electronic product, a power protection circuit is usually designed on a power circuit to prevent a circuit system from malfunctioning due to various unstable factors. Faults that may occur in the power supply circuit mainly include overcurrent, undervoltage, overvoltage, and the like. In the prior art, in order to ensure that a power supply circuit can operate safely and reliably, corresponding protection schemes (overcurrent protection, overvoltage protection, undervoltage protection and the like) are usually designed separately, for example, a current detection chip or a voltage detection chip and the like are used for monitoring the current or the voltage of the power supply circuit so as to monitor the working condition of the power supply circuit, find a fault in time and cut off the power supply of a fault device, thereby preventing the accident from expanding. However, in the prior art, each power protection scheme has a single protection function, and the reliability of the power circuit is low.
The power protection circuit and the circuit system provided by the embodiment of the application have the inventive concept that a plurality of power protection circuits with different functions are simultaneously arranged in the power protection circuit, wherein the power protection circuit comprises an overcurrent protection circuit, an overvoltage protection circuit, an undervoltage protection circuit and the like, and then the power protection circuit simultaneously has the overcurrent protection function, the overvoltage protection function and the undervoltage protection function through the level signal conversion circuit so as to improve the working reliability and stability of the power protection circuit, and can also realize the free switching and selective accepting and rejecting of all protection functions through the level signal conversion circuit, thereby improving the applicability of the power protection circuit. In addition, compared with the prior art that the detection of current or voltage is realized through a current detection chip or a voltage detection chip and the like, the overcurrent protection circuit, the overvoltage protection circuit and the undervoltage protection circuit in the power protection circuit provided by the embodiment of the application all adopt lower hardware cost, and the cost of the power protection circuit is effectively reduced.
An exemplary application scenario of the embodiments of the present application is described below.
The power protection circuit provided by the embodiment of the application can be integrated on a Printed Circuit Board (PCB). Fig. 1 is an exemplary application scenario architecture diagram provided in an embodiment of the present application, and as shown in fig. 1, the architecture mainly includes: a power supply, a power protection circuit, and a load device. The power protection circuit is used to protect the safety of the power circuit, for example, when the voltage or current of the power circuit is too large, the power circuit is disconnected from the load device to protect the load device. The embodiment of the present application does not limit the types of the power supply and the load device, wherein the working voltage of the power supply may be, for example, 3.3 volts, 5 volts, 12 volts, and the like, and the load device may be a gas meter, a water meter, a chromatograph, a flow meter, a terminal device, and the like, or may be a motor, a main control board, a communication module, and the like.
The following describes the power protection circuit provided in the embodiments of the present application, where each of the embodiments may be implemented separately, and any two or more embodiments may also be implemented in combination with each other, and the embodiments of the present application do not limit this.
Fig. 2 is a schematic structural diagram of a power protection circuit according to an embodiment of the present application, and as shown in fig. 2, the power protection circuit according to the embodiment of the present application may include: the device comprises an overcurrent protection circuit, an overvoltage protection circuit, an undervoltage protection circuit, a level signal conversion circuit and a control switch.
The input end of the overcurrent protection circuit, the input end of the overvoltage protection circuit and the input end of the undervoltage protection circuit are respectively connected with a power supply, the output end of the overcurrent protection circuit, the output end of the overvoltage protection circuit and the output end of the undervoltage protection circuit are respectively connected with the input of the level signal conversion circuit, and the output of the level signal conversion circuit is connected with load equipment through a control switch; the over-current protection circuit is used for performing over-current detection on the power supply and outputting a first output signal, the over-voltage protection circuit is used for performing over-voltage detection on the power supply and outputting a second output signal, and the under-voltage protection circuit is used for performing under-voltage detection on the power supply and outputting a third output signal; the level signal conversion circuit is used for controlling the control switch according to the first output signal, the second output signal and the third output signal so as to control the on-off between the load equipment and the power supply.
When a short circuit fault occurs in the power supply or an overload large current event occurs, the current of the power supply circuit is excessive, and the load equipment may be damaged. The overcurrent protection circuit is used for detecting the current of the power supply circuit to determine whether the current of the power supply circuit exceeds a preset current or not, and outputting a first output signal to the level signal conversion circuit according to a current detection result, for example, if the current of the power supply circuit exceeds the preset current, the first output signal is a high level signal; if the current of the power circuit does not exceed the predetermined current, the first output signal is a low level signal, which is taken as an example in the embodiment of the present application. The embodiment of the application does not limit the specific circuit structure of the over-current protection circuit.
The supply voltage of the power supply may be unstable, resulting in an excessive voltage condition. The overvoltage protection circuit is used for detecting the voltage of the power supply circuit to determine whether the voltage of the power supply circuit exceeds a first preset voltage, and outputting a second output signal to the level signal conversion circuit according to the voltage detection result, for example, if the voltage of the power supply circuit exceeds the preset voltage, the second output signal is a high level signal; if the voltage of the power circuit does not exceed the preset voltage, the second output signal is a low level signal, which is only taken as an example in the embodiment of the present application. The embodiment of the application does not limit the specific circuit structure of the overvoltage protection circuit.
When an alkaline battery or a lithium battery is used for power supply, the output voltage of the battery may be reduced continuously along with the reduction of the electric quantity of the battery, and the voltage may be too low. The under-voltage protection circuit is used for detecting the voltage of the power supply circuit to determine whether the voltage of the power supply circuit is lower than a second preset voltage, the second preset voltage is lower than a first preset voltage, and outputting a third output signal to the level signal conversion circuit according to the voltage detection result, for example, if the voltage of the power supply circuit is lower than the second preset voltage, the third output signal is a high level signal; if the voltage of the power circuit is not lower than the second predetermined voltage, the third output signal is a low level signal, which is taken as an example in the embodiment of the present application. The embodiment of the application does not limit the specific circuit structure of the under-voltage protection circuit.
After the level signal conversion circuit receives the first output signal, the second output signal and the third output signal, the control logic of the level signal conversion circuit can be designed according to different requirements of users. In one possible embodiment, if any one of the first output signal, the second output signal and the third output signal is at a high level, the power supply circuit and the load device are controlled to be disconnected, and the level signal conversion circuit may be designed as an or gate circuit, or may be designed as an nor gate circuit, etc. The embodiments of the present application are only examples thereof.
The embodiment of the present application does not limit the specific implementation manner of the level signal conversion circuit, for example, the level signal conversion circuit may be implemented by a logic gate circuit, or may be implemented by an electronic element design, or may be implemented by software in a chip, which is not limited in this embodiment of the present application.
The level signal conversion circuit may output a control signal according to the first output signal, the second output signal, and the third output signal to control on/off of the control switch, for example, when the control signal is a high level signal, the control switch is turned off, or when the control signal is a low level signal, the control switch is turned off.
In the embodiment of the application, through set up overcurrent protection circuit in power protection circuit, overvoltage crowbar and undervoltage protection circuit, can realize the overcurrent detection to the power respectively, overvoltage detection and undervoltage detection, and, according to overcurrent detection, overvoltage crowbar and undervoltage detection's output signal through level signal converting circuit, control switch, power protection circuit can have overcurrent protection function simultaneously, overvoltage crowbar and undervoltage protection function, power protection circuit's operational reliability and stability have been improved, and can also realize freely switching and selecting of each protect function through level signal converting circuit and accept or reject, power protection circuit's suitability has been improved.
It should be further noted that, in the embodiment shown in fig. 2, the power protection circuit includes an overcurrent protection circuit, an overvoltage protection circuit, and an undervoltage protection circuit, and overcurrent protection, overvoltage protection, and undervoltage protection can be implemented.
As another possible embodiment, a power protection circuit provided in another embodiment of the present application may include: the device comprises an overcurrent protection circuit, an overvoltage protection circuit, a level signal conversion circuit and a control switch. Namely, the power supply protection circuit can realize overcurrent protection and overvoltage protection.
The connection relationship and the working principle among the overcurrent protection circuit, the overvoltage protection circuit, the level signal conversion circuit and the control switch are the same as those in the embodiment shown in fig. 2, and are not described herein again.
As another possible embodiment, a power protection circuit provided in another embodiment of the present application may include: the device comprises an overcurrent protection circuit, an undervoltage protection circuit, a level signal conversion circuit and a control switch. That is, the power protection circuit can realize overcurrent protection and undervoltage protection.
The connection relationship and the working principle among the overcurrent protection circuit, the undervoltage protection circuit, the level signal conversion circuit and the control switch are the same as those in the embodiment shown in fig. 2, and are not described herein again.
As another possible embodiment, a power protection circuit provided in another embodiment of the present application may include: the overvoltage protection circuit, the undervoltage protection circuit, the level signal conversion circuit and the control switch. Namely, the power supply protection circuit can realize overvoltage protection and undervoltage protection.
The connection relationship and the working principle between the overvoltage protection circuit, the undervoltage protection circuit, the level signal conversion circuit and the control switch are the same as those in the embodiment shown in fig. 2, and are not described herein again.
In a possible implementation manner, fig. 3 is a schematic structural diagram of an overcurrent protection circuit provided in an embodiment of the application, and as shown in fig. 3, the overcurrent protection circuit includes: a first amplifying circuit 11 and a first resistor R1.
A first end of the first resistor R1 is connected with a power supply VCC, and a second end of the first resistor R1 is connected with the control switch; the first input end of the first amplifying circuit is connected with the first end of the first resistor R1, the second input end of the first amplifying circuit is connected with the second end of the first resistor R1, and the first amplifying circuit is used for amplifying the voltage on the first resistor R1 to generate and output a first output signal.
In order to realize the current detection of the power supply circuit, the current detection is generally realized by arranging a first resistor R1 between the power supply and the control switch, wherein, in order to avoid the influence of the first resistor on the power supply circuit and reduce the power consumption, the first resistor R1 with smaller resistance value can be selected. The voltage on the first resistor R1 is obtained by detecting the voltage difference between two ends of the first resistor R1, and then the current of the power supply circuit is determined through ohm's law. Since the resistance of the first resistor R1 is small, the voltage of the first resistor R1 is also relatively small, and in order to facilitate reading and determining the voltage across the first resistor R1, the voltage of the first resistor R1 is amplified by the first amplifying circuit 11, and the specific structure of the first amplifying circuit in the embodiment of the present application is not limited to the structure shown in fig. 3.
The first amplifying circuit outputs a first output signal, wherein the first output signal is the voltage on the amplified first resistor. In one possible implementation, the first output signal may be output to the level signal conversion circuit, and in another possible implementation, the first output signal may be processed by the processor and then output to the level signal conversion circuit. For example, the processor compares the first output signal with a preset voltage signal, and if the first output signal exceeds the preset voltage signal, the first output signal is a high level signal, and if the first output signal does not exceed the preset voltage signal, the first output signal is a low level signal.
In order to adapt to various application scenes, the overcurrent protection circuit can be flexibly set by setting the size of the preset voltage signal, adjusting the amplification factor of the first amplification circuit and the like, so that the flexibility and the applicability of the overcurrent protection circuit are improved. In the embodiment of the application, the detection of the current in the power supply VCC circuit is realized by detecting the voltage on the first resistor, and the reliability of the first output signal can be improved by amplifying the voltage on the first resistor R1 through the amplifying circuit.
In a possible implementation manner, as shown in fig. 3, in the overcurrent protection circuit provided in the embodiment of the present application, the first amplification circuit may include: a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5 and an operational amplifier U1.
One end of a second resistor R2 is grounded, the other end of the second resistor R2 is connected with a fourth resistor R4, a fourth resistor R4 is connected with the first end of a first resistor R1, one end of a third resistor R3 is connected with a fifth resistor R5, the other end of the third resistor R3 is connected with the output end of an operational amplifier U1, a fifth resistor R5 is connected with the second end of the first resistor R1, and the other end of the third resistor R3 is connected with the output end of an operational amplifier U1; a first input terminal of the operational amplifier U1 is connected between the second resistor R2 and the fourth resistor R4, and a second input terminal of the operational amplifier U1 is connected between the third resistor R3 and the fifth resistor R5.
By changing the resistance values of the second resistor, the third resistor, the fourth resistor and the fifth resistor, the amplification factor of the operational amplifier can be adjusted, and further the level value of the output signal of the first amplifying circuit can be adjusted. The embodiment of the application does not limit the specific resistance values of the second resistor, the third resistor, the fourth resistor and the fifth resistor, and the specific resistance values can be specifically set according to user requirements. The first input terminal of the operational amplifier may be a positive input terminal, and the second input terminal of the operational amplifier is a negative input terminal.
In a possible implementation manner, as shown in fig. 3, the overcurrent protection circuit further includes: a sequential circuit 12, preferably an RC circuit, wherein the sequential circuit 12 includes a sixth resistor R6 and a first capacitor; one end of the sixth resistor R6 is connected to the output end of the operational amplifier U1, the other end of the sixth resistor R6 is connected to the first capacitor and the level signal conversion circuit, respectively, and the first capacitor is grounded.
In the embodiment of the application, the filtering and the time delay of the output voltage are realized by arranging the sequential circuit in the overcurrent protection circuit. By adjusting the resistance value of the sixth resistor and the capacitance value of the first capacitor, different delay times can be obtained, the triggering time of the overcurrent protection circuit can be controlled, and the triggering sequence of the overcurrent protection circuit, the overvoltage protection circuit and the undervoltage protection circuit can be further controlled.
In a possible implementation manner, fig. 4 is a schematic structural diagram of an under-voltage protection circuit provided in an embodiment of the present application, and as shown in fig. 4, the under-voltage protection circuit includes: a first voltage dividing circuit 21 and a first switching circuit 22.
The first voltage division circuit 21 comprises a seventh resistor R7 and at least one eighth resistor R8, one end of the seventh resistor R7 is connected with the eighth resistor R8 in series, the other end of the seventh resistor R7 is grounded, and the eighth resistor R8 is connected with a power supply; one end of the first switch circuit 22 is connected between the seventh resistor R7 and the eighth resistor R8, and the other end of the first switch circuit 22 is connected to the level signal conversion circuit, and is configured to output a third output signal to the level signal conversion circuit.
In this embodiment of the present application, the number of the eighth resistors and the connection manner of the multiple eighth resistors are not limited, taking fig. 4 as an example, the number of the eighth resistors is two, two eighth resistors are connected in series, and for example, the multiple eighth resistors may also be connected in parallel, and for example, a part of the eighth resistors may also be connected in parallel and connected in series with a part of the eighth resistors. By arranging a plurality of eighth resistors and not being limited to the series-parallel connection mode of the plurality of eighth resistors, the flexibility of the first voltage division circuit can be improved so as to meet various voltage division design requirements.
Through the series voltage division of the seventh resistor and the eighth resistor, the input signal of the first switch circuit is the voltage on the seventh resistor, and the first switch circuit can output different third output signals by judging the comparison between the voltage on the seventh resistor and the second preset voltage.
In one possible embodiment, as shown in fig. 4, the first switch circuit 22 includes: a ninth resistor R9 and a first NMOS (Q1 in fig. 4), wherein the first NMOS refers to an NMOS. One end of a ninth resistor R9 is connected between the seventh resistor R7 and the eighth resistor R8, the other end of the ninth resistor R9 is connected with the gate of the first NMOS, the source of the first NMOS is grounded, and the drain of the first NMOS is connected with the level signal conversion circuit; the first NMOS is configured to output a high level signal to the level signal conversion circuit when the voltage across the seventh resistor R7 is less than a predetermined voltage.
The gate voltage of the first NMOS is a voltage across the seventh resistor, and when a difference between the gate voltage of the first NMOS and the source voltage of the first NMOS exceeds a certain value, the first NMOS is turned on, and the drain of the first NMOS outputs a low level signal. When the difference value between the grid voltage of the first NMOS and the source voltage of the first NMOS is smaller than a certain value, the first NMOS is disconnected, the drain of the first NMOS outputs a high level signal, and at the moment, the power supply circuit has the condition of undervoltage.
On the basis of the embodiment shown in fig. 4, in a possible implementation manner, fig. 5 is a schematic structural diagram of an under-voltage protection circuit provided in another embodiment of the present application, as shown in fig. 4 and fig. 5, the number of the eighth resistors R8 is multiple, and the multiple eighth resistors R8 are connected in series, and the under-voltage protection circuit further includes:
a feedback loop compensation circuit 23; the feedback loop compensation circuit 23 includes a tenth resistor R10 and a PMOS (Q2 in fig. 5), wherein the PMOS refers to a P-type metal oxide semiconductor. The source of the PMOS is connected between the power supply and the tenth resistor R10, the gate of the PMOS is connected between the tenth resistor R10 and the level signal conversion circuit, and the drain of the PMOS is connected between the plurality of eighth resistors R8.
The source voltage of the PMOS is power supply voltage VCC, when the power supply is powered on or is slightly interfered by the outside world, the VCC voltage may have voltage fluctuation and exceed the power supply voltage VCC, at the moment, the difference value between the source voltage of the PMOS and the grid voltage of the PMOS reaches the conduction threshold value of the PMOS, the PMOS tube is conducted and consumes the overshoot voltage of the power supply voltage, the difference value between the source voltage of the PMOS and the grid voltage of the PMOS is lower than the conduction threshold value of the PMOS, the PMOS tube is turned off, the protection mechanism of an overvoltage circuit or an undervoltage circuit is prevented from being triggered mistakenly in the power-on process, and the stability of the power supply circuit is improved.
In a possible implementation manner, as shown in fig. 5, the under-voltage protection circuit further includes: the timing circuit 24 is preferably an RC circuit, and the timing circuit 24 includes an eleventh resistor R11 and a second capacitor C2; one end of an eleventh resistor R11 is connected to the drain of the first NMOS, the other end of the eleventh resistor R11 is connected to the second capacitor C2 and the level signal conversion circuit, respectively, and the second capacitor C2 is grounded.
In the embodiment of the application, the filtering and the time delay of the output voltage are realized by arranging the sequential circuit in the undervoltage protection circuit. By adjusting the resistance value of the eleventh resistor and the capacitance value of the second capacitor, different delay times can be obtained, the trigger time of the undervoltage protection circuit can be controlled, and the trigger sequence of the overcurrent protection circuit, the overvoltage protection circuit and the undervoltage protection circuit can be further controlled.
On the basis of any one of the foregoing embodiments of fig. 2 to fig. 5, in a possible implementation manner, fig. 6 is a schematic structural diagram of an overvoltage protection circuit provided in an embodiment of the present application, and as shown in fig. 6, the overvoltage protection circuit in the power protection circuit provided in the embodiment of the present application may include: a second voltage divider circuit 31 and a comparator U2.
The second voltage division circuit 31 comprises a twelfth resistor R12 and a thirteenth resistor R13, the twelfth resistor R12 is connected with the thirteenth resistor R13 in series, the twelfth resistor R12 is connected with a power supply, and the thirteenth resistor R13 is grounded; a first input end of the comparator U2 is connected between the twelfth resistor R12 and the thirteenth resistor R13, a second input end of the comparator U2 is connected between the seventh resistor and the eighth resistor R8, and an output end of the comparator U2 is connected with the level signal conversion circuit; the comparator U2 is used to output a second output signal to the level signal conversion circuit.
The twelfth resistor and the thirteenth resistor are used for dividing the power supply voltage so as to input the voltage on the thirteenth resistor to the first input end of the comparator, the voltage input by the second input end of the comparator is the voltage on the seventh resistor, and the second output signal is output through the output end of the comparator. In a possible embodiment, the first input terminal of the comparator may be an inverting input terminal, and the second input terminal of the comparator is a non-inverting input terminal, and in this case, if the voltage across the seventh resistor is greater than the voltage across the thirteenth resistor, the comparator outputs a high level signal indicating that the power supply voltage is over-voltage. If the voltage on the seventh resistor is not greater than the voltage on the thirteenth resistor, the comparator outputs a low level signal, which indicates that the power supply voltage is not over-voltage.
In this embodiment, the power supply circuit can be adapted to power supply circuits with different voltage requirements by adjusting the resistance values of the twelfth resistor and the thirteenth resistor, and in addition, the embodiment of the present invention does not limit the resistance values and the number of the twelfth resistor and the thirteenth resistor, for example, the number of the twelfth resistor may be two or more, and the number of the thirteenth resistor may also be two or more.
On the basis of the embodiment shown in fig. 6, in a possible implementation manner, fig. 7 is a schematic structural diagram of an overvoltage protection circuit provided in another embodiment of the present application, and in combination with fig. 6 and fig. 7, the overvoltage protection circuit provided in the embodiment of the present application includes: a timing circuit 32, preferably an RC circuit, the timing circuit 32 including a fourteenth resistor R14 and a third capacitor C3; one end of a fourteenth resistor R14 is connected with the output end of the comparator U2, the other end of the fourteenth resistor R14 is respectively connected with the third capacitor C3 and the level signal conversion circuit, and the third capacitor is grounded.
In the embodiment of the application, the filtering and the time delay of the output voltage are realized by arranging the sequential circuit in the overvoltage protection circuit. By adjusting the resistance of the fourteenth resistor and the capacitance of the third capacitor, different delay times can be obtained, and the triggering time of the overvoltage protection circuit can be controlled, so that the triggering sequence of the overcurrent protection circuit, the overvoltage protection circuit and the undervoltage protection circuit can be controlled.
On the basis of any of the embodiments of fig. 2 to 7, in the embodiments of the present application, it is described as an example that when the power supply circuit has an overcurrent problem, the first output signal is a high level signal, when the power supply circuit has an overvoltage problem, the second output signal is a high level signal, when the power supply circuit has an undervoltage problem, the third output signal is a high level signal, and when the signal output by the level signal conversion circuit is a low level signal, the control switch is controlled to be turned off. For example, when the signal output by the level signal conversion circuit is a high level signal, the control switch may be controlled to be turned off, and for example, when the power circuit has an overcurrent problem, the first output signal is a low level signal, and so on.
In a possible implementation manner, fig. 8 is a schematic structural diagram of a level signal conversion circuit provided in an embodiment of the present application, and as shown in fig. 8, the level signal conversion circuit in the power protection circuit provided in the embodiment of the present application may include: a first diode D1, a second diode D2, a third diode D3, a first transistor Q3, and a second transistor Q4.
The anode of the first diode D1 is connected with the output end of the over-current protection circuit, the anode of the second diode D2 is connected with the output end of the under-voltage protection circuit, and the anode of the third diode D3 is connected with the output end of the over-voltage protection circuit; the cathode of the first diode D1, the cathode of the second diode D2 and the cathode of the third diode D3 are respectively connected with the base of the first triode Q3 and the base of the second triode Q4, the emitter of the first triode Q3 is connected with the power supply VCC, the emitter of the second triode Q4 is grounded GND, and the collector of the first triode Q3 and the collector of the second triode Q4 are connected with the control switch.
The level signal conversion circuit may further include a fifteenth resistor R15 connected to a low level (-VCC). In this embodiment, if there is a high level signal in the first output signal, the second output signal, and the third output signal, the signal input to the cathode of the first transistor by the diode is a high level signal, at this time, the first transistor is turned off, the second transistor is turned on, and the level signal conversion circuit outputs a low level signal. If the first output signal, the second output signal and the third output signal are all low level signals, the first triode is conducted, the second triode is cut off, and the level signal conversion circuit outputs high level signals.
When the level signal conversion circuit outputs a low level signal, the control switch is controlled to be disconnected with the load equipment, and when the level signal conversion circuit outputs a high level signal, the control switch is controlled to be connected with the load equipment.
In another possible implementation manner, the level signal conversion circuit in the power protection circuit provided in this embodiment may also be implemented by a control chip, where the type of the control chip is not limited in this embodiment, and for example, the control chip may be a Micro Controller Unit (MCU).
In a possible implementation manner, the level signal conversion circuit comprises a control chip, wherein a first pin of the control chip is connected with an output end of the overcurrent protection circuit, a second pin of the control chip is connected with an output end of the undervoltage protection circuit, and a third pin of the control chip is connected with an output end of the overvoltage protection circuit; and a fourth pin of the control chip is connected with the control switch. The control chip is used for controlling the control switch according to the first output signal, the second output signal and the third output signal so as to control the on-off between the load equipment and the power supply.
In the embodiment of the application, the control chip controls the on-off between the load equipment and the power supply according to the output signals of the protection circuits, the types of the protection circuits can be flexibly and freely switched, the mutual combinability of the protection circuits can be coordinated, the triggering sequence of the protection circuits can be set, and the application occasion is more flexible.
On the basis of the embodiment shown in fig. 8, in a possible implementation manner, fig. 9 is a schematic structural diagram of a control switch provided in an embodiment of the present application, and as shown in fig. 9, the control switch of the power protection circuit provided in the embodiment of the present application may include: the second NMOS (Q5 in fig. 9).
The gate of the second NMOS, the collector of the first transistor Q3, and the collector of the second transistor Q4 are connected, the source of the second NMOS is connected to the power supply, and the drain of the second NMOS is connected to the load device.
When the level signal conversion circuit outputs a low level signal, the gate voltage of the second NMOS is lower than the source voltage of the second NMOS, the second NMOS is cut off, and the power supply is disconnected with the load equipment. When the level signal conversion circuit outputs a high level signal, the gate voltage of the second NMOS is higher than the source voltage of the second NMOS, the second NMOS is conducted, and the power supply is conducted with the load equipment.
In one possible implementation, if the power supply is connected reversely, the source power supply of the second NMOS is zero, and whether the level signal conversion circuit outputs a high level signal or a low level signal, the second NMOS is turned off, and the power supply is disconnected from the load device. Therefore, the second NMOS is used as the control switch, so that the on-off of the power supply and the load equipment can be controlled according to the level signal output by the level signal conversion circuit, and the reverse connection of the power supply can be effectively prevented. And compared with the prior art, the reverse connection prevention of the power supply is realized by arranging the diode between the power supply and the load equipment, and the defect of high power consumption caused by inherent large voltage drop and large current passing when the diode is adopted is overcome because the on-resistance of the NMOS is in the milliohm level.
In one possible embodiment, the control switch further comprises: the third NMOS (Q6 in fig. 9).
The gate of the third NMOS, the collector of the first transistor Q3, and the collector of the second transistor Q4 are connected, the source of the third NMOS is connected to the load device, and the drain of the third NMOS is connected to the drain of the second NMOS.
By designing the third NMOS, the third NMOS is cut off when the current in the load equipment flows to the third NMOS through the source electrode of the third NMOS, and the function of preventing reverse flow is achieved.
On the basis of the above embodiments, fig. 10 is a schematic structural diagram of a power protection circuit according to another embodiment of the present application, where reference numerals in fig. 10 refer to reference numerals in fig. 2 to fig. 9, and the working principle thereof may refer to the above embodiments and is not repeated.
The embodiment of the application provides a circuit system, which comprises a power supply, a load device and a power supply protection circuit provided by any one of the above embodiments. The contents and effects of the above embodiments can be referred to, and are not described in detail.
Finally, it should be noted that: the above embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should 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 or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present application.
Claims (14)
1. A power protection circuit, comprising: at least two circuits of an overcurrent protection circuit, an overvoltage protection circuit and an undervoltage protection circuit; the power supply protection circuit also comprises a level signal conversion circuit and a control switch;
the input end of the over-current protection circuit, the input end of the over-voltage protection circuit and the input end of the under-voltage protection circuit are respectively connected with a power supply, the output end of the over-current protection circuit, the output end of the over-voltage protection circuit and the output end of the under-voltage protection circuit are respectively connected with the input of the level signal conversion circuit, and the output of the level signal conversion circuit is connected with load equipment through the control switch;
the over-current protection circuit is used for performing over-current detection on the power supply and outputting a first output signal, the over-voltage protection circuit is used for performing over-voltage detection on the power supply and outputting a second output signal, and the under-voltage protection circuit is used for performing under-voltage detection on the power supply and outputting a third output signal;
the level signal conversion circuit is used for controlling the control switch according to the first output signal, the second output signal and the third output signal so as to control the on-off between the load equipment and the power supply.
2. The power protection circuit according to claim 1, wherein the overcurrent protection circuit comprises: a first amplifying circuit and a first resistor;
the first end of the first resistor is connected with the power supply, and the second end of the first resistor is connected with the control switch;
the first input end of the first amplifying circuit is connected with the first end of the first resistor, the second input end of the first amplifying circuit is connected with the second end of the first resistor, and the first amplifying circuit is used for amplifying the voltage on the first resistor to generate and output the first output signal.
3. The power protection circuit of claim 2, wherein the first amplification circuit comprises: the operational amplifier is connected with the first resistor, the second resistor, the third resistor, the fourth resistor, the fifth resistor and the operational amplifier;
one end of the second resistor is grounded, the other end of the second resistor is connected with the fourth resistor, the fourth resistor is connected with the first end of the first resistor, one end of the third resistor is connected with the fifth resistor, the other end of the third resistor is connected with the output end of the operational amplifier, the fifth resistor is connected with the second end of the first resistor, and the other end of the third resistor is connected with the output end of the operational amplifier;
the first input end of the operational amplifier is connected between the second resistor and the fourth resistor, and the second input end of the operational amplifier is connected between the third resistor and the fifth resistor.
4. The power protection circuit of claim 1, wherein the under-voltage protection circuit comprises: a first voltage dividing circuit and a first switching circuit;
the first voltage division circuit comprises a seventh resistor and at least one eighth resistor, one end of the seventh resistor is connected with the eighth resistor in series, the other end of the seventh resistor is grounded, and the eighth resistor is connected with the power supply;
one end of the first switch circuit is connected between the seventh resistor and the eighth resistor, and the other end of the first switch circuit is connected with the level signal conversion circuit and is used for outputting the third output signal to the level signal conversion circuit.
5. The power protection circuit of claim 4, wherein the first switching circuit comprises: a ninth resistor and a first NMOS;
one end of the ninth resistor is connected between the seventh resistor and the eighth resistor, the other end of the ninth resistor is connected with the grid electrode of the first NMOS, the source electrode of the first NMOS is grounded, and the drain electrode of the first NMOS is connected with the level signal conversion circuit;
and the first NMOS is used for outputting a high level signal to the level signal conversion circuit when the voltage of the seventh resistor is less than a preset voltage.
6. The power protection circuit according to claim 4, wherein the number of the eighth resistors is plural, and plural ones of the eighth resistors are connected in series with each other,
the undervoltage protection circuit further comprises: a feedback loop compensation circuit;
the feedback loop compensation circuit comprises a tenth resistor and a PMOS, wherein the source electrode of the PMOS is connected between the power supply and the tenth resistor, the grid electrode of the PMOS is connected between the tenth resistor and the level signal conversion circuit, and the drain electrode of the PMOS is connected between the eighth resistors.
7. The power protection circuit of claim 4, wherein the over-voltage protection circuit comprises: a second voltage dividing circuit and a comparator;
the second voltage division circuit comprises a twelfth resistor and a thirteenth resistor, the twelfth resistor is connected with the thirteenth resistor in series, the twelfth resistor is connected with the power supply, and the thirteenth resistor is grounded;
a first input end of the comparator is connected between the twelfth resistor and the thirteenth resistor, a second input end of the comparator is connected between the seventh resistor and the eighth resistor, and an output end of the comparator is connected with the level signal conversion circuit;
the comparator is used for outputting the second output signal to the level signal conversion circuit.
8. The power protection circuit according to any one of claims 1 to 7, wherein at least one of the over-current protection circuit, the over-voltage protection circuit, and the under-voltage protection circuit comprises a sequential circuit;
the sequential circuit is used for carrying out time delay processing on a first output signal of the overcurrent protection circuit; and/or
The sequential circuit is used for carrying out time delay processing on a second output signal of the overvoltage protection circuit; and/or
And the sequential circuit is used for carrying out time delay processing on a third output signal of the undervoltage protection circuit.
9. The power protection circuit of claim 8, wherein:
the sequential circuit comprises a sixth resistor and a first capacitor; one end of the sixth resistor is connected with the output end of the operational amplifier, the other end of the sixth resistor is respectively connected with the first capacitor and the level signal conversion circuit, and the first capacitor is grounded; and/or
The sequential circuit comprises an eleventh resistor and a second capacitor; one end of the eleventh resistor is connected with the drain electrode of the first NMOS, the other end of the eleventh resistor is respectively connected with the second capacitor and the level signal conversion circuit, and the second capacitor is grounded; and/or
The timing circuit comprises a fourteenth resistor and a third capacitor; one end of the fourteenth resistor is connected with the output end of the comparator, the other end of the fourteenth resistor is respectively connected with the third capacitor and the level signal conversion circuit, and the third capacitor is grounded.
10. The power protection circuit of claim 1, wherein the level signal conversion circuit comprises a first diode, a second diode, a third diode, a first transistor, and a second transistor,
the anode of the first diode is connected with the output end of the over-current protection circuit, the anode of the second diode is connected with the output end of the under-voltage protection circuit, and the anode of the third diode is connected with the output end of the over-voltage protection circuit;
the cathode of the first diode, the cathode of the second diode and the cathode of the third diode are respectively connected with the base electrode of the first triode and the base electrode of the second triode, the emitting electrode of the first triode is connected with the power supply, the emitting electrode of the second triode is grounded, and the collecting electrode of the first triode and the collecting electrode of the second triode are connected with the control switch.
11. The power protection circuit of claim 10, wherein the control switch comprises: the second NMOS is used for carrying out the second NMOS,
the grid electrode of the second NMOS, the collector electrode of the first triode and the collector electrode of the second triode are connected, the source electrode of the second NMOS is connected with the power supply, and the drain electrode of the second NMOS is connected with the load equipment.
12. The power protection circuit of claim 11, wherein the control switch further comprises: the third NMOS is a second NMOS,
the grid electrode of the third NMOS, the collector electrode of the first triode and the collector electrode of the second triode are connected, the source electrode of the third NMOS is connected with the load equipment, and the drain electrode of the third NMOS is connected with the drain electrode of the second NMOS.
13. The power protection circuit of claim 1, wherein the level signal conversion circuit comprises a control chip,
a first pin of the control chip is connected with the output end of the over-current protection circuit, a second pin of the control chip is connected with the output end of the under-voltage protection circuit, and a third pin of the control chip is connected with the output end of the over-voltage protection circuit; and a fourth pin of the control chip is connected with the control switch.
14. A circuit system comprising a power supply, a load device and a power protection circuit as claimed in any one of claims 1 to 13.
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| CN202011394771.5A CN114597864A (en) | 2020-12-02 | 2020-12-02 | Power supply protection circuit and circuit system |
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| CN202011394771.5A CN114597864A (en) | 2020-12-02 | 2020-12-02 | Power supply protection circuit and circuit system |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114661649A (en) * | 2022-04-12 | 2022-06-24 | 湖南国科微电子股份有限公司 | Bias circuit |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105305797A (en) * | 2015-10-15 | 2016-02-03 | 中国兵器工业集团第二一四研究所苏州研发中心 | Overvoltage and undervoltage protection circuit for output of DC/DC power supply |
| CN111952938A (en) * | 2020-07-31 | 2020-11-17 | 深圳市信锐网科技术有限公司 | Input protection circuit and method of power supply |
| CN213817224U (en) * | 2020-12-02 | 2021-07-27 | 金卡智能集团股份有限公司 | Power supply protection circuit and circuit system |
-
2020
- 2020-12-02 CN CN202011394771.5A patent/CN114597864A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105305797A (en) * | 2015-10-15 | 2016-02-03 | 中国兵器工业集团第二一四研究所苏州研发中心 | Overvoltage and undervoltage protection circuit for output of DC/DC power supply |
| CN111952938A (en) * | 2020-07-31 | 2020-11-17 | 深圳市信锐网科技术有限公司 | Input protection circuit and method of power supply |
| CN213817224U (en) * | 2020-12-02 | 2021-07-27 | 金卡智能集团股份有限公司 | Power supply protection circuit and circuit system |
Non-Patent Citations (1)
| Title |
|---|
| 李艳丽: "开关电源中保护电路的研究与设计", 《中国优秀硕士学位论文全文数据库（电子期刊）·工程科技Ⅱ辑》, no. 1, 15 January 2016 (2016-01-15), pages 13 - 14 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114661649A (en) * | 2022-04-12 | 2022-06-24 | 湖南国科微电子股份有限公司 | Bias circuit |
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