CN116865208A - Undervoltage protection circuit - Google Patents

Undervoltage protection circuit Download PDF

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Publication number
CN116865208A
CN116865208A CN202310756926.2A CN202310756926A CN116865208A CN 116865208 A CN116865208 A CN 116865208A CN 202310756926 A CN202310756926 A CN 202310756926A CN 116865208 A CN116865208 A CN 116865208A
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China
Prior art keywords
electrically connected
module
node
power supply
resistor
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CN202310756926.2A
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Chinese (zh)
Inventor
范超
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Shanghai Xinggan Semiconductor Co ltd
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Shanghai Xinggan Semiconductor Co ltd
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Priority to CN202310756926.2A priority Critical patent/CN116865208A/en
Publication of CN116865208A publication Critical patent/CN116865208A/en
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Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
    • H02H3/24—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to undervoltage or no-voltage
    • H02H3/243—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to undervoltage or no-voltage for DC systems
    • 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
    • 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
    • H02M1/0048—Circuits or arrangements for reducing losses
    • H02M1/0054—Transistor switching losses
    • 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
    • H02M1/14—Arrangements for reducing ripples from dc input or output
    • 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
    • H02M1/44—Circuits or arrangements for compensating for electromagnetic interference in converters or inverters

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Measurement Of Current Or Voltage (AREA)

Abstract

The application provides an undervoltage protection circuit. The undervoltage protection circuit includes: one end of the power supply voltage sampling module is electrically connected to the power supply end to acquire power supply voltage, and the other end of the power supply voltage sampling module is electrically connected to the ground end; the input end of the band-gap reference module is electrically connected to the power supply end, the power supply voltage sampling module and the ground end respectively, and the output end of the band-gap reference module is electrically connected to the first node; the switch module is electrically connected with the power supply voltage sampling module at a first end, the ground terminal at a second end and the output terminal of the circuit at a control end through a first inverter; a pull-up module, one end of which is electrically connected to the power supply end, and the other end of which is electrically connected to the first node; the driving module is electrically connected with the power supply end at a first end, the second end is electrically connected with the second node, and the control end is electrically connected with the first node; the current detection module is electrically connected with the second node at one end and the ground at the other end; and one end of the trigger module is electrically connected to the second node, and the other end of the trigger module is coupled to the output end of the circuit. According to the technical scheme, the undervoltage protection circuit without a voltage stabilizing tube is provided, so that the power consumption and the complexity of the circuit can be reduced, and the noise immunity is improved; the stability of the product parameters is improved, and the manufacturing cost is not increased.

Description

Undervoltage protection circuit
Technical Field
The application relates to the technical field of integrated circuits, in particular to an undervoltage protection circuit.
Background
The traditional undervoltage protection circuit consists of a power supply voltage sampling circuit, a reference circuit, a voltage comparator circuit and a filter circuit. The sampling circuit generally adopts a resistor voltage division mode to obtain the proportional voltage value of the power supply VCC, the reference circuit generally adopts a Zener reference or a band gap reference as the reference voltage of the comparator, the filter circuit generally adopts a filter consisting of a current source and a capacitor, the filter consisting of a resistor and a capacitor can also be adopted, the output of the comparator is also used as a feedback signal to control the adoption circuit, so that the negative threshold value is lower than the positive threshold value, the difference value of the negative threshold value and the positive threshold value is the hysteresis voltage, and the hysteresis voltage is used for stabilizing the output of the undervoltage protection circuit and preventing oscillation.
The reference circuit of the traditional undervoltage protection circuit is provided by a voltage stabilizing tube or a band gap reference circuit, and because the voltage stabilizing tube or the voltage stabilizing tube which is not matched cannot be provided in certain processes, and in order to reduce the power consumption and the complexity of the circuit, the redundant band gap reference circuit cannot be used, the design of the undervoltage protection circuit is very complex, and the power consumption and the circuit area are also increased.
Aiming at the problem that a voltage stabilizing tube cannot be provided or is not suitable in certain processes, or an excessive band gap reference circuit cannot be used in order to reduce power consumption and circuit complexity, the undervoltage protection circuit capable of greatly reducing power consumption and circuit complexity and improving noise resistance is needed.
Disclosure of Invention
The application aims to solve the technical problem of providing an undervoltage protection circuit which can greatly reduce power consumption and complexity of the circuit and improve noise immunity.
In order to solve the above problems, the present application provides an undervoltage protection circuit, comprising: one end of the power supply voltage sampling module is electrically connected to the power supply end to acquire power supply voltage, and the other end of the power supply voltage sampling module is electrically connected to the ground end; the input end of the band-gap reference module is electrically connected to the power supply end, the power supply voltage sampling module and the ground end respectively, and the output end of the band-gap reference module is electrically connected to the first node; the switch module is electrically connected with the power supply voltage sampling module at a first end, the ground terminal at a second end and the output terminal of the circuit at a control end through a first inverter; a pull-up module, one end of which is electrically connected to the power supply end, and the other end of which is electrically connected to the first node; the driving module is electrically connected with the power supply end at a first end, the second end is electrically connected with the second node, and the control end is electrically connected with the first node; the current detection module is electrically connected with the second node at one end and the ground at the other end; and one end of the trigger module is electrically connected to the second node, and the other end of the trigger module is coupled to the output end of the circuit.
In some embodiments, when the circuit starts to power up, the power supply voltage is lower than a first threshold voltage, the switch module is turned on, and an output end of the circuit outputs a first level and enters an under-voltage locking state; when the power supply voltage starts to rise, the band gap reference module pulls down the voltage of the first node, so that the current flowing through the driving module is increased, the voltage of the second node is increased, when the voltage of the second node is increased to a first threshold voltage, the triggering module outputs a second level, and the output end of the circuit outputs the second level so as to release the under-voltage locking state and start to work normally; wherein the second level is greater than the first level.
In some embodiments, when the power supply voltage starts to drop from the second level, the bandgap reference module raises the voltage of the first node, so that the current flowing through the driving module decreases, the voltage of the second node drops, when the voltage of the second node is lower than a second threshold voltage, the triggering module outputs a first level, the switching module is turned on, and the output terminal of the circuit outputs the first level and enters an under-voltage locking state.
In some embodiments, the power supply voltage sampling module is composed of a first resistor, a second resistor and a third resistor connected in series; one end of the first resistor is electrically connected to the power supply end, and the other end of the first resistor is electrically connected to a third node; one end of the second resistor is electrically connected to the third node, and the other end of the second resistor is electrically connected to a fourth node; one end of the third resistor is electrically connected to the fourth node, and the other end of the third resistor is electrically connected to the ground; wherein the bandgap reference module is electrically connected to the third node of the supply voltage sampling module, and the first end of the switching module is electrically connected to the fourth node of the supply voltage sampling module.
In some embodiments, the bandgap reference module includes a first transistor, a second transistor, a third transistor, a fourth transistor; the emitter of the first triode is electrically connected to the power supply end, and the collector and the base of the first triode are electrically connected to the base of the second triode and the collector of the third triode after being short-circuited; the emitter of the second triode is electrically connected to the power supply end, and the collector of the second triode is electrically connected to the first node; the emitter of the third triode is electrically connected to the ground through a fourth resistor and a fifth resistor which are connected in series, and the base of the third triode is respectively and electrically connected to the power supply voltage sampling module and the base of the fourth triode; and the emitter electrode of the fourth triode is electrically connected to the common end of the fourth resistor and the fifth resistor, and the collector electrode of the fourth triode is electrically connected to the first node.
In some embodiments, the switch module employs an NMOS transistor having a source electrically connected to ground, a drain electrically connected to the fourth node, and a gate electrically connected to the output of the circuit.
In some embodiments, the driving module employs a PMOS transistor having a source electrically connected to the power supply terminal, a drain electrically connected to the second node, and a gate electrically connected to the first node.
In some embodiments, the pull-up module employs a pull-up resistor, the current detection module employs a current detection resistor, and the trigger module employs a schmitt trigger.
In some embodiments, the circuit further comprises a filtering module electrically connected to the triggering module and the ground, respectively, and to an output of the circuit through the first inverter.
In some embodiments, the filtering module includes a sixth resistor, a first capacitor, a second inverter, and a second capacitor; one end of the sixth resistor is connected with the output end of the trigger module, and the other end of the sixth resistor is electrically connected to the first polar plate of the first capacitor and the second inverter respectively; the second electrode plate of the first capacitor is electrically connected to the ground terminal; the second inverter is electrically connected to the first inverter; the first polar plate of the second capacitor is electrically connected to the output end of the second inverter, and the second polar plate of the second capacitor is electrically connected to the ground end.
According to the technical scheme, the undervoltage protection circuit without a voltage stabilizing tube is provided, so that the power consumption and the complexity of the circuit can be reduced, and the noise immunity is improved; the stability of the product parameters is improved, and the manufacturing cost is not increased.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application as claimed. Techniques, methods, and apparatus known to one of ordinary skill in the relevant art may not be discussed in detail, but should be considered part of the specification where appropriate.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments of the present application will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort for a person of ordinary skill in the art.
FIG. 1 is a schematic diagram of an embodiment of an under-voltage protection circuit according to the present application;
FIG. 2 is a schematic circuit diagram illustrating the connection of an embodiment of the undervoltage protection circuit according to the present application;
Detailed Description
The following description of the embodiments of the present application will be made more apparent and fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the application are shown. All other embodiments, which can be made by those skilled in the art without the exercise of inventive faculty, are intended to be within the scope of the present application, based on the embodiments herein.
An embodiment of the application provides an undervoltage protection circuit.
Please refer to fig. 1, which is a schematic diagram illustrating a structure of an embodiment of the undervoltage protection circuit according to the present application. As shown in fig. 1, the undervoltage protection circuit according to this embodiment includes: the power supply voltage sampling module 10, one end of which is electrically connected to a power supply end to acquire a power supply voltage VCC, and the other end of which is electrically connected to a ground end GND; the band gap reference module 11, the input end is electrically connected to the power supply end, the power supply voltage sampling module 10 and the ground end GND respectively, and the output end is electrically connected to the first node A1; a switch module 12 having a first terminal electrically connected to the power voltage sampling module 10, a second terminal electrically connected to the ground terminal GND, and a control terminal electrically connected to an output terminal OUT of the circuit through a first inverter B1; a pull-up module 13 having one end electrically connected to the power supply terminal and the other end electrically connected to the first node A1; a driving module 14 having a first end electrically connected to the power supply end, a second end electrically connected to the second node A2, and a control end electrically connected to the first node A1; a current detection module 15, one end of which is electrically connected to the second node A2, and the other end of which is electrically connected to the ground GND; the trigger module 16 has one end electrically connected to the second node A2 and the other end coupled to the output terminal OUT of the circuit.
In this embodiment, when the circuit starts to power up, the power supply voltage sampling module 10 may obtain that the power supply voltage VCC is lower than the first threshold voltage, the switch module 12 is turned on, and the output terminal OUT of the circuit outputs the first level and enters the under-voltage locking state; when the power supply voltage VCC starts to rise, the bandgap reference module 11 pulls down the voltage of the first node A1, so that the current flowing through the driving module 14 increases, the voltage of the second node A2 increases, when the voltage of the second node A2 increases to the first threshold voltage, the triggering module 15 outputs a second level, and the output terminal OUT of the circuit outputs the second level to release the under-voltage locking state to start normal operation; wherein the second level is greater than the first level.
In this embodiment, when the power supply voltage VCC starts to decrease from the second level, the bandgap reference module 11 increases the voltage of the first node A1, so that the current flowing through the driving module 14 decreases, the voltage of the second node A2 decreases, and when the voltage of the second node A2 is lower than the second threshold voltage, the triggering module 16 outputs the first level, the switching module 12 is turned on, and the output terminal OUT of the circuit outputs the first level and enters the under-voltage locking state.
Please refer to fig. 2, which is a schematic circuit connection diagram of an embodiment of the undervoltage protection circuit according to the present application. As shown in fig. 2, the undervoltage protection circuit according to this embodiment includes: the power supply voltage sampling module 10, one end of which is electrically connected to a power supply end to acquire a power supply voltage VCC, and the other end of which is electrically connected to a ground end GND; the band gap reference module 11, the input end is electrically connected to the power supply end, the power supply voltage sampling module 10 and the ground end GND respectively, and the output end is electrically connected to the first node A1; a switch module 12 having a first terminal electrically connected to the power voltage sampling module 10, a second terminal electrically connected to the ground terminal GND, and a control terminal electrically connected to an output terminal OUT of the circuit through a first inverter B1; a pull-up module 13 having one end electrically connected to the power supply terminal and the other end electrically connected to the first node A1; a driving module 14 having a first end electrically connected to the power supply end, a second end electrically connected to the second node A2, and a control end electrically connected to the first node A1; a current detection module 15, one end of which is electrically connected to the second node A2, and the other end of which is electrically connected to the ground GND; the trigger module 16 has one end electrically connected to the second node A2 and the other end coupled to the output terminal OUT of the circuit.
In this embodiment, the power supply voltage sampling module 10 is configured to obtain a power supply voltage VCC. The power supply voltage sampling module 10 is formed by connecting a first resistor R1, a second resistor R2 and a third resistor R3 in series. One end of the first resistor R1 is electrically connected to the power supply end to acquire a power supply voltage VCC, and the other end is electrically connected to a third node A3; one end of the second resistor R2 is electrically connected to the third node A3, and the other end is electrically connected to the fourth node A4; one end of the third resistor R3 is electrically connected to the fourth node A4, and the other end is electrically connected to the ground GND; wherein the bandgap reference module 11 is electrically connected to the third node A3 of the supply voltage sampling module 10, and the first end of the switching module 12 is electrically connected to the fourth node A4 of the supply voltage sampling module 10.
In this embodiment, the bandgap reference module 11 is configured to compensate the temperature of the circuit, so as to obtain a high-precision reference voltage. The band gap reference module 11 comprises a first triode Q1, a second triode Q2, a third triode Q3 and a fourth triode Q4. The emitter of the first triode Q1 is electrically connected to the power supply end, and the collector and the base of the first triode Q1 are electrically connected to the base of the second triode Q2 and the collector of the third triode Q3 after being short-circuited; the emitter of the second triode Q2 is electrically connected to the power supply end, and the collector of the second triode Q2 is electrically connected to the first node A1; the emitter of the third triode Q3 is electrically connected to the ground GND through a fourth resistor R4 and a fifth resistor R5 connected in series, and the base thereof is electrically connected to the third node A3 of the power supply voltage sampling module 10 and the base of the fourth triode Q4, respectively; an emitter of the fourth triode Q4 is electrically connected to a common terminal of the fourth resistor R4 and the fifth resistor R5, and a collector thereof is electrically connected to the first node A1.
In this embodiment, the switch module 12 is configured to control the circuit to enter the undervoltage lock state at a low level. The switch module 12 employs an NMOS transistor D1, wherein a source of the NMOS transistor D1 is electrically connected to the ground GND, a drain thereof is electrically connected to the fourth node A4, and a gate thereof is electrically connected to the output terminal OUT of the circuit. In other embodiments, the switch module 12 may also employ at least one of a diode, a triode, a field effect transistor, and a thyristor.
In this embodiment, the pull-up module 13 is used for dividing the voltage of the circuit. The pull-up module 13 adopts a pull-up resistor R7, and the specific resistance value of the pull-up resistor R7 is selected according to the actual power consumption requirement. One end of the pull-up resistor R7 is electrically connected to the power supply end, and the other end of the pull-up resistor R7 is electrically connected to the first node A1.
In this embodiment, the driving module 14 employs a PMOS transistor D2, where a source of the PMOS transistor D2 is electrically connected to the power supply terminal, a drain of the PMOS transistor D2 is electrically connected to the second node A2, and a gate of the PMOS transistor D2 is electrically connected to the first node A1.
In this embodiment, the current detection module 15 adopts a current detection resistor R8, and a specific resistance value of the current detection circuit R8 is selected according to an actual power consumption requirement. The current detection resistor R8 has one end electrically connected to the second node A2 and the other end electrically connected to the ground GND.
In this embodiment, the triggering module 16 employs a schmitt trigger D3, where the schmitt trigger D3 has two threshold voltages, and an input voltage that changes a circuit state when the input voltage rises from a low level to a high level is a first threshold voltage; the input voltage that changes the state of the circuit in the process of decreasing the input voltage from the high level to the low level is the second threshold voltage. The schmitt trigger D3 has one end electrically connected to the second node A2 and the other end coupled to the output OUT of the circuit.
In this embodiment, the circuit further comprises a filtering module 17. The circuit can generate narrower descending pulse, namely noise, in the working process, at the moment, the undervoltage protection circuit can induce the descending two-off working state of the power supply voltage to cause false triggering, and not only can the working efficiency of the circuit be influenced, but also the circuit is burnt out, so that the filter module 17 is designed in the undervoltage protection circuit to resist noise. The filter module 17 is electrically connected to the trigger module 16 and the ground GND, respectively, and to the output terminal OUT of the circuit through the first inverter B1.
In this embodiment, the filtering module 17 includes a sixth resistor R6, a first capacitor C1, a second inverter B2, and a second capacitor C2. One end of the sixth resistor R6 is connected to the output end of the trigger module 16, and the other end is electrically connected to the first polar plate of the first capacitor C1 and the second inverter B2, respectively; the second plate of the first capacitor C1 is electrically connected to the ground GND; the second inverter B2 is electrically connected to the first inverter B1; the first plate of the second capacitor C2 is electrically connected to the output terminal of the second inverter B2, and the second plate thereof is electrically connected to the ground GND.
The working principle of the undervoltage protection circuit according to the present application is further explained below with reference to fig. 2.
When the under-voltage protection circuit starts to power up, the power supply voltage VCC is lower than a first threshold voltage, the NMOS transistor D1 is turned on, and the output terminal OUT of the circuit outputs a first level and enters an under-voltage locking state. When the power supply voltage VCC starts to rise, the base voltage of the third transistor Q3 and the base voltage of the fourth transistor Q4 rise, and V of the third transistor Q3 BE Voltage and V of the fourth triode Q4 BE The voltage can be regarded as substantially unchanged, and it is possible to obtain an increase in the emitter voltage of the third transistor Q3 and an increase in the emitter voltage of the fourth transistor Q4, resulting in an increase in the current flowing through the fifth resistor R5, the current flowing through the fourth resistor R4 being unchanged, so that the current increasing through the fifth resistor R5 flows from the fourth transistor Q4. Because the current mirror formed by the first triode Q1 and the second triode Q2 makes the current of the first triode Q1 and the current of the second triode Q2 equal, the increased current of the fourth triode Q4 can be obtained and provided by the pull-up resistor R7, so that the voltage of the first node A1 is reduced, the current flowing through the PMOS transistor D2 is increased, and the voltage of the second node A2 is increased. When the voltage of the second node A2 rises to the first threshold voltage of the schmitt trigger D3, the schmitt trigger D3 outputs a second level, and the output terminal OUT of the undervoltage protection circuit outputs the second level so as to release the undervoltage locking state and start to work normally. Wherein the second level is greater than the first levelFlat.
When the power supply voltage VCC decreases from the second level, the base voltage of the third transistor Q3 and the base voltage of the fourth transistor Q4 also decrease, V of the third transistor Q3 BE Voltage and V of the fourth triode Q4 BE The voltage can be regarded as being substantially unchanged, and the emitter voltage of the third transistor Q3 and the emitter voltage of the fourth transistor Q4 can be obtained to be reduced, resulting in a reduction of the current flowing through the fifth resistor R5, and the current flowing through the fourth transistor Q4 is reduced as the current flowing through the fourth resistor R4 is unchanged. Since the current mirror formed by the first transistor Q1 and the second transistor Q2 makes the currents of the first transistor Q1 and the second transistor Q2 equal, the current of the pull-up resistor R7 decreases accordingly, resulting in an increase in the voltage of the first node A1, a decrease in the current flowing through the PMOS transistor D2, and a decrease in the voltage of the second node A2. When the voltage of the second node A2 is lower than the second threshold voltage of the schmitt trigger D3, the schmitt trigger D3 outputs a first level, the NMOS transistor D1 is turned on, and the output terminal OUT of the under-voltage protection circuit outputs the first level and enters an under-voltage locking state.
According to the technical scheme, the undervoltage protection circuit without a voltage stabilizing tube is provided, so that the power consumption and the complexity of the circuit can be reduced, and the noise immunity is improved; the stability of the product parameters is improved, and the manufacturing cost is not increased.
It should be noted that in this document, relational terms such as "first" and "second" and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, the statement "comprises" and "comprising" does not exclude the presence of other elements than those listed in any process, method, article, or apparatus that comprises the element.
The embodiments of the present application are described in a related manner, and identical and similar parts of the embodiments are all referred to each other, and each embodiment is mainly different from other embodiments.
The foregoing is merely a preferred embodiment of the present application and is not intended to limit the scope of the present application. It should be noted that modifications and adaptations to the present application may occur to one skilled in the art without departing from the principles of the present application and are intended to be comprehended within the scope of the present application.

Claims (10)

1. An undervoltage protection circuit, comprising:
one end of the power supply voltage sampling module is electrically connected to the power supply end to acquire power supply voltage, and the other end of the power supply voltage sampling module is electrically connected to the ground end;
the input end of the band-gap reference module is electrically connected to the power supply end, the power supply voltage sampling module and the ground end respectively, and the output end of the band-gap reference module is electrically connected to the first node;
the switch module is electrically connected with the power supply voltage sampling module at a first end, the ground terminal at a second end and the output terminal of the circuit at a control end through a first inverter;
a pull-up module, one end of which is electrically connected to the power supply end, and the other end of which is electrically connected to the first node; the driving module is electrically connected with the power supply end at a first end, the second end is electrically connected with the second node, and the control end is electrically connected with the first node;
the current detection module is electrically connected with the second node at one end and the ground at the other end;
and one end of the trigger module is electrically connected to the second node, and the other end of the trigger module is coupled to the output end of the circuit.
2. The undervoltage protection circuit of claim 1, wherein,
when the circuit starts to be electrified, the power supply voltage is lower than a first threshold voltage, the switch module is conducted, and the output end of the circuit outputs a first level and enters an under-voltage locking state;
when the power supply voltage starts to rise, the band gap reference module pulls down the voltage of the first node, so that the current flowing through the driving module is increased, the voltage of the second node is increased, when the voltage of the second node is increased to a first threshold voltage, the triggering module outputs a second level, and the output end of the circuit outputs the second level so as to release the under-voltage locking state and start to work normally; wherein the second level is greater than the first level.
3. The undervoltage protection circuit of claim 2, wherein,
when the power supply voltage starts to drop from the second level, the band gap reference module lifts the voltage of the first node, so that the current flowing through the driving module is reduced, the voltage of the second node drops, when the voltage of the second node is lower than a second threshold voltage, the triggering module outputs the first level, the switching module is conducted, and the output end of the circuit outputs the first level and enters an under-voltage locking state.
4. The undervoltage protection circuit of claim 1, wherein the supply voltage sampling module is comprised of a first resistor, a second resistor, and a third resistor in series;
one end of the first resistor is electrically connected to the power supply end, and the other end of the first resistor is electrically connected to a third node;
one end of the second resistor is electrically connected to the third node, and the other end of the second resistor is electrically connected to a fourth node;
one end of the third resistor is electrically connected to the fourth node, and the other end of the third resistor is electrically connected to the ground;
wherein the bandgap reference module is electrically connected to the third node of the supply voltage sampling module, and the first end of the switching module is electrically connected to the fourth node of the supply voltage sampling module.
5. The undervoltage protection circuit of claim 1, wherein the bandgap reference module comprises a first transistor, a second transistor, a third transistor, and a fourth transistor;
the emitter of the first triode is electrically connected to the power supply end, and the collector and the base of the first triode are electrically connected to the base of the second triode and the collector of the third triode after being short-circuited;
the emitter of the second triode is electrically connected to the power supply end, and the collector of the second triode is electrically connected to the first node;
the emitter of the third triode is electrically connected to the ground through a fourth resistor and a fifth resistor which are connected in series, and the base of the third triode is respectively and electrically connected to the power supply voltage sampling module and the base of the fourth triode;
and the emitter electrode of the fourth triode is electrically connected to the common end of the fourth resistor and the fifth resistor, and the collector electrode of the fourth triode is electrically connected to the first node.
6. The undervoltage protection circuit of claim 1, wherein the switching module employs an NMOS transistor having a source electrically connected to ground, a drain electrically connected to the fourth node, and a gate electrically connected to an output of the circuit.
7. The undervoltage protection circuit of claim 1, wherein the drive module employs a PMOS transistor having a source electrically connected to the power supply terminal, a drain electrically connected to the second node, and a gate electrically connected to the first node.
8. The undervoltage protection circuit of claim 1, wherein,
the pull-up module adopts a pull-up resistor, the current detection module adopts a current detection resistor, and the trigger module adopts a Schmitt trigger.
9. The undervoltage protection circuit of claim 1, further comprising a filter module electrically connected to the trigger module and ground, respectively, and to an output of the circuit through the first inverter.
10. The undervoltage protection circuit of claim 9, wherein the filter module comprises a sixth resistor, a first capacitor, a second inverter, and a second capacitor;
one end of the sixth resistor is connected with the output end of the trigger module, and the other end of the sixth resistor is electrically connected to the first polar plate of the first capacitor and the second inverter respectively;
the second electrode plate of the first capacitor is electrically connected to the ground terminal;
the second inverter is electrically connected to the first inverter;
the first polar plate of the second capacitor is electrically connected to the output end of the second inverter, and the second polar plate of the second capacitor is electrically connected to the ground end.
CN202310756926.2A 2023-06-25 2023-06-25 Undervoltage protection circuit Pending CN116865208A (en)

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Application Number Priority Date Filing Date Title
CN202310756926.2A CN116865208A (en) 2023-06-25 2023-06-25 Undervoltage protection circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
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CN116865208A true CN116865208A (en) 2023-10-10

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117595626A (en) * 2023-11-28 2024-02-23 北京伽略电子股份有限公司 Multi-output enabling circuit
CN118630696A (en) * 2024-08-08 2024-09-10 电子科技大学 Anti-radiation high-voltage undervoltage protection circuit

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117595626A (en) * 2023-11-28 2024-02-23 北京伽略电子股份有限公司 Multi-output enabling circuit
CN117595626B (en) * 2023-11-28 2024-05-31 北京伽略电子股份有限公司 Multi-output enabling circuit
CN118630696A (en) * 2024-08-08 2024-09-10 电子科技大学 Anti-radiation high-voltage undervoltage protection circuit

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