CN114583663A - Monitoring protection circuit and step-down switching power supply circuit - Google Patents

Monitoring protection circuit and step-down switching power supply circuit Download PDF

Info

Publication number
CN114583663A
CN114583663A CN202210238720.6A CN202210238720A CN114583663A CN 114583663 A CN114583663 A CN 114583663A CN 202210238720 A CN202210238720 A CN 202210238720A CN 114583663 A CN114583663 A CN 114583663A
Authority
CN
China
Prior art keywords
voltage
circuit
monitored
output
protection circuit
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202210238720.6A
Other languages
Chinese (zh)
Other versions
CN114583663B (en
Inventor
郇伟伟
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Suzhou Inspur Intelligent Technology Co Ltd
Original Assignee
Suzhou Inspur Intelligent Technology Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Suzhou Inspur Intelligent Technology Co Ltd filed Critical Suzhou Inspur Intelligent Technology Co Ltd
Priority to CN202210238720.6A priority Critical patent/CN114583663B/en
Publication of CN114583663A publication Critical patent/CN114583663A/en
Application granted granted Critical
Publication of CN114583663B publication Critical patent/CN114583663B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • 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
    • 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
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
    • H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
    • H02M3/10—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M3/145—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M3/155—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/156—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
    • Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

The application relates to a monitoring protection circuit and a step-down switching power supply circuit, wherein the input end of the monitoring protection circuit is connected with the monitored voltage output end of a monitored circuit, and the output end of the monitoring protection circuit is connected with the enabling input end of the monitored circuit; the monitoring protection circuit includes: a comparison unit and a feedback unit; the comparison unit compares the voltage value output by the monitored voltage output end with a preset voltage range, and if the voltage value exceeds the voltage range, a first level is output to the feedback unit; when the feedback unit is input with the first level, the feedback unit outputs a second level to the enable input end of the monitored circuit so as to stop the monitored circuit. The application provides a control protection circuit who contains comparing element and feedback unit carries out real time monitoring and feedback to being monitored control circuit, avoids because of divider resistance inefficacy or the unusual condition that leads to by monitoring control circuit's output voltage abnormality, protection rear end circuit, reduces the risk that components and parts or integrated circuit board burnt, reduces the influence that output voltage is unusual.

Description

Monitoring protection circuit and step-down switching power supply circuit
Technical Field
The present disclosure relates to electronic circuits, and particularly to a monitoring protection circuit and a buck switching power supply circuit.
Background
The power supply requirements of the mainboard and other board cards in the server are low voltage and large current, so a voltage reduction type switching power supply scheme is adopted. The basic circuit of the voltage-reducing type switching power supply comprises a primary rectification and filtering circuit, an energy storage inductor, a secondary filter capacitor, a voltage conversion circuit, a sampling and feedback circuit and the like, and the key for converting high voltage into low voltage and stably outputting the low voltage is to realize the stable work of all board cards in the server.
In a traditional implementation mode, the output voltage is generally regulated by monitoring the voltage of the voltage-dividing resistor, but the effectiveness of the method depends on the performance of the voltage-dividing resistor, and the failure of the voltage-dividing resistor in the application process can cause some adverse effects. For example, when the voltage dividing resistor fails, it may cause the output voltage of the voltage conversion circuit to continuously increase or the output voltage of the voltage conversion circuit to continuously decrease. The continuous increase of the output voltage can cause negative effects on the stability of the board power supply circuit, possibly burn back-end chips, components, loads and the like, and even burn the whole board or server, so that serious economic loss is caused. The continuous reduction of the output voltage can cause the back-end circuit to work abnormally, and part of the board card power supply link falls into a paralyzed state, so that the normal operation of the load is seriously influenced.
Disclosure of Invention
To solve the problems in the prior art, the application provides a monitoring protection circuit and a buck switching power supply circuit so as to deal with the conditions that voltage output is abnormal and affects a rear-end line.
Specifically, the embodiment of the invention provides the following technical scheme:
in a first aspect, a monitoring protection circuit is provided, where an input terminal of the monitoring protection circuit is connected to a monitored voltage output terminal of a monitored circuit, and an output terminal of the monitoring protection circuit is connected to an enable input terminal of the monitored circuit; the monitoring protection circuit includes: a comparison unit and a feedback unit;
the comparison unit compares the voltage value output by the monitored voltage output end with a preset voltage range, and if the voltage value output by the monitored voltage output end exceeds the voltage range, a first level is output to the feedback unit;
when the feedback unit is input with a first level, a second level is output to the enable input end of the monitored circuit, so that the monitored circuit stops working.
According to an implementable manner of an embodiment of the present application, the first level and the second level are both low levels.
According to an implementable manner in an embodiment of the present application, the comparing unit includes: a first operational amplifier and a second operational amplifier;
the inverting input end of the first operational amplifier is connected to the monitored voltage output end, the input voltage of the homodromous input end of the first operational amplifier is set to be the highest value of the preset voltage range, and the output end of the first operational amplifier is connected to the input end of the feedback unit;
the same-direction input end of the second operational amplifier is connected to the monitored voltage output end, the input voltage of the reverse input end of the second operational amplifier is set to be the lowest value of the preset voltage range, and the output end of the second operational amplifier is connected to the input end of the feedback unit.
According to an implementation manner of the embodiment of the present application, the feedback unit is an and gate logic unit.
According to one implementation manner in the embodiment of the present application, the monitoring protection circuit further includes: a power supply unit; the power supply unit comprises a field effect tube; the grid electrode of the field effect transistor is connected with the normal output end of the power supply of the monitored circuit, the source electrode of the field effect transistor is connected with the power supply input ends of the first operational amplifier and the second operational amplifier, and the drain electrode of the field effect transistor is connected with the drain power supply.
According to an implementable manner of an embodiment of the present application, the monitoring protection circuit further includes: an alarm unit; the input end of the alarm unit is connected with the output end of the feedback unit, and when the feedback unit outputs a low level, the alarm unit gives an alarm.
According to an implementation manner in the embodiment of the present application, the alarm unit includes: a NOT gate logic unit and an indicator light; the input end of the NOT gate logic unit is connected with the output end of the feedback unit, and the output end of the NOT gate logic unit is connected with the indicator light.
According to one implementation of an embodiment of the present application, the monitored circuit includes a voltage conversion circuit.
In a second aspect, a buck switching power supply circuit is provided, where the buck switching power supply circuit includes a voltage conversion circuit and the monitoring protection circuit of the first aspect; the voltage conversion circuit converts an input first voltage into a second voltage; the second voltage is lower than the first voltage; the input end of the monitoring protection circuit is connected with the feedback output end of the voltage conversion circuit; and the output end of the monitoring protection circuit is connected with the enabling input end of the voltage conversion circuit.
According to an implementation manner in the embodiment of the present application, the feedback output terminal of the voltage conversion circuit adjusts the output voltage through the connected first voltage-dividing resistor and the second voltage-dividing resistor.
According to the technical content provided by the embodiment of the application, the application provides the monitoring protection circuit comprising the comparison unit and the feedback unit, the monitoring protection circuit is connected with the monitored voltage output end of the monitored circuit, the monitored voltage of the monitored circuit is compared with the preset voltage range, the voltage value output by the monitored voltage output end is fed back to the monitored circuit when abnormal, the monitored circuit stops working, real-time monitoring and feedback can be carried out on the monitored circuit, the condition that the output voltage of the monitored circuit is abnormal due to the failure or abnormality of a divider resistor is effectively avoided, the rear-end circuit is protected, the risk of burning of rear ends such as components or boards can be reduced, the influence range of the abnormality of the monitored voltage is reduced, and the economic loss is reduced.
Drawings
FIG. 1 is a circuit schematic of a monitoring protection circuit according to one embodiment;
FIG. 2 is a circuit diagram of a monitoring protection circuit according to an embodiment;
FIG. 3 is a circuit diagram of a buck switching power supply circuit according to an embodiment;
Detailed Description
The present application will be described in further detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.
Fig. 1 is a schematic circuit diagram of a monitoring protection circuit according to an embodiment of the present disclosure, and as shown in fig. 1, an input terminal of the monitoring protection circuit 1 is connected to a monitored voltage output terminal of a monitored circuit 2, and an output terminal of the monitoring protection circuit 1 is connected to an enable input terminal of the monitored circuit 2; the monitoring protection circuit 1 includes: a comparison unit 11 and a feedback unit 12; the comparison unit 11 compares the voltage value output by the monitored voltage output end with a preset voltage range, and outputs a first level to the feedback unit 12 if the voltage value output by the monitored voltage output end exceeds the voltage range; when the first level is inputted to the feedback unit 12, the second level is outputted to the enable input terminal of the monitored circuit 2, so that the monitored circuit 2 stops operating.
Specifically, the input terminal of the monitoring protection circuit 1 is connected to the monitored voltage output terminal of the monitored circuit 2, the output terminal of the monitoring protection circuit 1 is connected to the enable input terminal of the monitored circuit 2, wherein the enable input terminal can control the operating state of the monitored circuit 2, the output voltage of the output terminal of the monitored circuit 2 has a voltage range of normal operation when the monitored circuit 2 is in normal operation, the voltage range is preset for the comparison unit 11, the voltage value output by the monitored voltage output terminal is compared with the preset voltage range, if the voltage value output by the monitored voltage output terminal exceeds the preset voltage range, it is indicated that the monitored circuit 2 has abnormality, therefore, a first level is output to the feedback unit 12, when the feedback unit 12 is input with the first level, a second level is fed back to the enable input terminal of the monitored circuit 2, the enable input terminal of the monitored circuit 2 controls the monitored circuit 2 to stop operating when the second level is input, thus, real-time monitoring and protection of the monitored circuit 2 can be realized.
As a practical matter, if the enable input of the monitored circuit 2 is active high, both the first level and the second level are low. As another way of realizing this, if the enable input of the monitored circuit 2 is active low, both the first level and the second level are high. In the following embodiment, the first level and the second level are both low.
Fig. 2 is a circuit structure diagram of a monitoring protection circuit according to an embodiment of the present application, and the monitoring protection circuit is described in detail below with reference to fig. 2 and the embodiment.
According to one implementation manner in the embodiment of the present application, the comparison unit 11 includes two operational amplifiers: a first operational amplifier a and a second operational amplifier B. It should be noted that the expressions "first", "second", and the like in the embodiments of the present application do not have the meanings of order, size, and number, and are merely used for the sake of name differentiation. For example, the first operational amplifier and the second operational amplifier are merely used to distinguish the two operational amplifiers in name.
The inverting input end of the first operational amplifier a is connected to the monitored voltage output end of the monitored circuit 2, the input voltage of the homodromous input end of the first operational amplifier a is set to be the highest value of the preset voltage range, and the output end of the first operational amplifier a is connected to the input end of the feedback unit 12; the inverting input terminal of the second operational amplifier B is connected to the monitored voltage output terminal, the input voltage of the inverting input terminal of the second operational amplifier B is set to the lowest value of the preset voltage range, and the output terminal of the second operational amplifier B is connected to the input terminal of the feedback unit 12.
Specifically, the inverting input terminal of the first operational amplifier a is connected to the monitored voltage output terminal, and the input voltage of the non-inverting input terminal of the first operational amplifier a is set to the highest value of the preset voltage range, whereby when the output voltage of the monitored voltage output terminal abnormally increases and exceeds the maximum value of the operating voltage range, the first operational amplifier a outputs a low level; the same-direction input end of the second operational amplifier B is connected to the monitored voltage output end, and the input voltage of the reverse input end of the second operational amplifier B is set to be the lowest value of the preset voltage range, so that when the output voltage of the monitored voltage output end is abnormally reduced and exceeds the minimum value of the working voltage range, the operational amplifier B outputs low level. The outputs of the first and second operational amplifiers a, B are connected to the input of the feedback unit 12. Therefore, when the output voltage abnormally increases or abnormally decreases, the feedback unit 12 is input with a low level.
According to an implementation manner of the embodiment of the present application, the feedback unit 12 is an and gate logic unit.
Specifically, as shown in fig. 2, the feedback unit 12 is an and logic unit, and when any one of the operational amplifiers in the comparison unit 11 inputs a low level to the and logic unit, the and logic unit outputs the low level to the enable input terminal of the monitored circuit 2. The Enable (EN, Enable) input terminal, also called Enable terminal or chip select terminal, is an input terminal of a control signal for controlling the operating state of the monitored circuit 2. Normally, the enable input is active high, i.e. the monitored circuit 2 enters the operating state when the enable input is input high. Therefore, in this embodiment, when the and logic unit outputs a low level to the enable input terminal of the monitored circuit 2, the enable input terminal stops working, so as to achieve the purpose of protecting the circuit.
According to one implementation manner in the embodiment of the present application, the monitoring protection circuit 1 further includes: a power supply unit 13; the power supply unit 13 is used to supply power to the first operational amplifier a and the second operational amplifier B.
According to one implementation manner in the embodiment of the present application, the power supply unit 13 includes a field effect transistor; the gate of the fet is connected to the Power supply normal (PG) output terminal of the monitored circuit 2, the source is connected to the Power supply input terminals of the first and second operational amplifiers, and the drain is connected to the drain Power supply.
According to one implementation manner in the embodiment of the present application, the monitoring protection circuit 1 further includes: an alarm unit 14; the input end of the alarm unit 14 is connected to the output end of the feedback unit 12, and when the feedback unit 12 outputs a low level, an alarm is given.
Specifically, the input end of the alarm unit 14 is connected to the output end of the feedback unit 12, when the output voltage of the monitored circuit 2 is abnormal, the feedback unit 12 outputs a low level to the alarm unit 14, and the alarm unit 14 gives an alarm in a manner of lighting, ringing and the like, so that convenience is provided for troubleshooting of maintenance personnel, a fault is locked quickly, and loss is reduced.
According to an implementation manner of the embodiment of the present application, as shown in fig. 2, the alarm unit 14 includes a not gate logic unit and an indicator light, an input end of the not gate logic unit is connected to an output end of the feedback unit 12, an output end of the not gate logic unit is connected to the indicator light, when there is an abnormality in the output voltage of the monitored circuit 2, the feedback unit 12 outputs a low level, and when the low level is input to the not gate logic unit, an output end of the not gate logic unit outputs a high level to the indicator light, so that the indicator light is turned on to send an alarm, which may provide convenience for a maintenance worker to troubleshoot the fault.
According to one implementation of the embodiment of the present application, the monitored circuit 2 includes a voltage conversion circuit.
Specifically, the power supply requirements of the motherboard and other boards in the server are low voltage and large current, so that the power is supplied by the voltage conversion circuit, and the stability of the output voltage of the voltage conversion circuit is a key for realizing the stable operation of each board in the server, so as to serve as one of the application scenarios, the monitored circuit 2 in this embodiment may include the voltage conversion circuit to monitor the feedback voltage of the voltage conversion circuit. The monitoring protection circuit 1 can also be applied to monitoring power supply circuits of various mainboards and other board cards in a server.
According to the specific embodiment provided by the application, the technical scheme provided by the application can have the following advantages:
this application is through providing a control protection circuit who contains comparing element and feedback unit, with the voltage output end by monitoring circuit is connected, output voltage that will be monitored circuit compares with predetermineeing the voltage range, feed back to by monitoring circuit when output voltage is unusual, make by monitoring circuit stop work, can carry out real time monitoring and feedback to being monitored circuit, effectively avoid because of the condition that divider resistance became invalid or unusually lead to by monitoring circuit's output voltage is unusual, and then protect the rear end circuit, can reduce the risk that components and parts or integrated circuit board burn out, reduce the influence scope of output voltage malfunction, reduce economic loss.
It is to be understood that not necessarily all advantages described above may be achieved in accordance with any one method or article of manufacture implementing the present application.
Fig. 3 is a circuit configuration diagram of a buck switching power supply circuit provided in an embodiment of the present application, where the buck switching power supply circuit includes a voltage conversion circuit 3 and a monitoring protection circuit 1 in the above embodiment; the voltage conversion circuit 3 converts the input first voltage into a second voltage; in the step-down switch circuit, the second voltage is lower than the first voltage, namely, the high voltage is converted into the low voltage; the input end of the monitoring protection circuit 1 is connected with the feedback output end of the voltage conversion circuit 3; the output end of the monitoring protection circuit 1 is connected with the enable input end of the voltage conversion circuit 3.
Specifically, in the step-down switching power supply circuit, a circuit requiring real-time monitoring is the voltage conversion circuit 3, and the voltage conversion circuit 3 is connected to the monitoring protection circuit 1 as the monitored circuit 2 in the above embodiment. The voltage conversion circuit 3 converts the input first voltage into a second voltage, wherein the second voltage is lower than the first voltage, thereby achieving the purpose of voltage reduction. The input end of the monitoring protection circuit 1 is connected with the feedback output end, namely an FB pin, of the voltage conversion circuit 3; the output end of the monitoring protection circuit 1 is connected with the enable input end, namely an EN pin, of the voltage conversion circuit 3. Therefore, the problem that when the voltage conversion circuit 3 of the buck switching power supply circuit breaks down, for example, the divider resistor is short-circuited or broken, the output voltage continuously increases or the output voltage is lower than a target value can be solved.
According to one implementation manner in the embodiment of the present application, the feedback output terminal of the voltage conversion circuit 3 adjusts the output voltage through the connected first voltage-dividing resistor R1 and second voltage-dividing resistor R2.
Specifically, as shown in fig. 3, the feedback output terminal, i.e., the FB pin, of the voltage conversion circuit 3 adjusts the output Voltage (VOU) through the connected first voltage-dividing resistor R1 and second voltage-dividing resistor R2T). In the present buck switching power supply scheme, the Voltage converting circuit 3 may be disposed in a VR (Voltage regulator) chip. The VR chip is provided with an FB feedback pin, and the pin is connected with divider resistors R1 and R2 to regulate output voltage. In practical application, it is necessary to refer to the reference voltage V built in the chiprefAccording to VrefThe voltage of the second voltage-dividing resistor, namely the voltage across the resistor R2, is monitored and compared with V to select the voltage-dividing resistors R1 and R2 with proper resistance values (VOUT. R2/(R1+ R2)refComparing, making the output voltage reach the target value and outputting stably. In the power supply scheme of the buck switching power supply, the reliability of the voltage dividing resistor plays a decisive role in realizing stable output of the output voltage. When the divider resistance breaks down, the VR chip should obtain the signal of this state in time and react, avoids producing serious influence to rear end circuit and load.
In combination with the implementation manner in the above embodiment, the output voltage is 1.2V, VrefThe chip solution of 0.6V is taken as an example, and the embodiments of the present application are described by way of example, and include the following contents:
1) the resistance values of the upper voltage-dividing resistor R1 and the lower voltage-dividing resistor R2 are both set to 10k omega, and if the output voltage is allowed to fluctuate by 10 percent up and down, namely the normal output voltage range is 1.08-1.32V, the voltage at the two ends of the second voltage-dividing resistor R2 is taken as the sampling voltage VmSampling voltage VmThe range is 0.54-0.66V;
2) setting V of operational amplifier Aref1Set V of the operational amplifier B to 0.66Vref20.54V;
3) after power-on, the VOUT outputs normally, when the VOUT output reaches a preset proportion (for example, 90%) of a target voltage, a PG signal, namely a power supply normal signal, is pulled high, an MOS (metal oxide semiconductor) tube is conducted, and the monitoring protection circuit 1 is controlled to start;
4) when the second voltage-dividing resistor R2 is short-circuited or the first voltage-dividing resistor R1 is open-circuited, VmReduced to 0; the operational amplifier A outputs high level, the operational amplifier B outputs low level, the low level is output through the AND gate logic unit, the enable input end EN is input with low level, and the voltage conversion circuit stops voltage output; low level via "The NOT gate logic unit is converted into high level, and the LED indicator light is turned on.
5) When the second voltage-dividing resistor R2 is broken or the first voltage-dividing resistor R1 is short-circuited, VmAn abnormal increase; the operational amplifier A outputs a low level, the operational amplifier B outputs a high level, the low level is output through the AND gate logic unit, the low level is input into the enable input end EN, and the voltage conversion circuit stops voltage output; the low level is converted into high level through a NOT gate logic unit, and an LED indicator lamp is lightened.
It can be seen from the above example that, in the case that the first voltage-dividing resistor R1 or the second voltage-dividing resistor R2 has a fault, the first voltage-dividing resistor R1 or the second voltage-dividing resistor R2 can be monitored and fed back to the monitored circuit in time through the monitoring protection circuit, so that the monitored circuit stops working, adverse effects on a rear-end circuit of the monitored circuit, such as a component or a board card connected to the rear end, are avoided, and economic losses are reduced. Meanwhile, by arranging the alarm unit, convenience can be provided for maintenance personnel to check faults, and the fault position can be quickly locked.
In addition, fig. 3 describes a buck switching power supply circuit as an example, and the monitoring protection circuit provided in the present application may also be applied to other application scenarios to implement monitoring and protection on a monitored circuit, which is not listed here.
It should be noted that, in the above embodiments of the present application, a scenario in which the enable input terminal is active at a high level is taken as an example. In another embodiment of the present application, when the enable input terminal of the monitored circuit is active low, the principle of the monitoring protection circuit is not changed, and the specific structure can be implemented with slight changes within the spirit principle of the above embodiment. For example, the same-direction input end of the first operational amplifier a is connected to the monitored voltage output end of the monitored circuit 2, the input voltage of the inverting input end of the first operational amplifier a is set to the highest value of the preset voltage range, and the output end of the first operational amplifier a is connected to the input end of the feedback unit; the inverting input end of the second operational amplifier B is connected to the monitored voltage output end, the input voltage of the homodromous input end of the second operational amplifier B is set to be the lowest value of the preset voltage range, and the output end of the second operational amplifier B is connected to the input end of the feedback unit. When there is an abnormal increase or abnormal decrease in the circuit voltage, the feedback unit is input with a high level. The feedback unit may be implemented as an or gate logic unit. When the feedback unit is inputted with a high level, the feedback unit outputs the high level to the enable input end of the monitored circuit, so that the monitored circuit stops working. In this case, the alarm unit may include an indicator light connected to an output terminal of the or gate logic unit, and the indicator light may be turned on to alarm in a case where the or gate logic unit outputs a high level.
The same and similar parts among the various embodiments are referred to each other, and each embodiment focuses on differences from other embodiments.
The circuits in the above embodiments of the present application may be ordinary circuits, or may also be in the form of integrated chips, and the like, which is not limited in the present application.
The above-described embodiments should not be construed as limiting the scope of the present application. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions may be made in accordance with design requirements and other factors. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims (10)

1. A monitoring protection circuit is characterized in that the input end of the monitoring protection circuit is connected with the monitored voltage output end of a monitored circuit, and the output end of the monitoring protection circuit is connected with the enabling input end of the monitored circuit; the monitoring protection circuit includes: a comparison unit and a feedback unit;
the comparison unit compares the voltage value output by the monitored voltage output end with a preset voltage range, and if the voltage value output by the monitored voltage output end exceeds the voltage range, a first level is output to the feedback unit;
when the feedback unit is input with a first level, a second level is output to the enable input end of the monitored circuit, so that the monitored circuit stops working.
2. The method of claim 1, wherein the first level and the second level are both low.
3. The monitoring protection circuit of claim 2, wherein the comparison unit comprises: a first operational amplifier and a second operational amplifier;
the inverting input end of the first operational amplifier is connected to the monitored voltage output end, the input voltage of the homodromous input end of the first operational amplifier is set to be the highest value of the preset voltage range, and the output end of the first operational amplifier is connected to the input end of the feedback unit;
the same-direction input end of the second operational amplifier is connected to the monitored voltage output end, the input voltage of the reverse input end of the second operational amplifier is set to be the lowest value of the preset voltage range, and the output end of the second operational amplifier is connected to the input end of the feedback unit.
4. The monitoring protection circuit of claim 3, wherein the feedback unit is an AND logic unit.
5. The monitoring protection circuit of claim 3, further comprising: a power supply unit;
the power supply unit comprises a field effect tube; the grid electrode of the field effect transistor is connected with the normal output end of the power supply of the monitored circuit, the source electrode of the field effect transistor is connected with the power supply input ends of the first operational amplifier and the second operational amplifier, and the drain electrode of the field effect transistor is connected with the drain power supply.
6. The monitoring protection circuit of claim 1, further comprising: an alarm unit;
the input end of the alarm unit is connected with the output end of the feedback unit, and when the feedback unit outputs a low level, the alarm unit gives an alarm.
7. The monitoring protection circuit of claim 6, wherein the alarm unit comprises: a NOT gate logic unit and an indicator light; the input end of the NOT gate logic unit is connected with the output end of the feedback unit, and the output end of the NOT gate logic unit is connected with the indicator light.
8. The monitoring protection circuit of any one of claims 1 to 7, wherein the monitored circuit comprises a voltage conversion circuit.
9. A buck switching power supply circuit including a voltage conversion circuit and a monitoring protection circuit as claimed in any one of claims 1 to 8;
the voltage conversion circuit converts an input first voltage into a second voltage; the second voltage is lower than the first voltage;
the input end of the monitoring protection circuit is connected with the feedback output end of the voltage conversion circuit; and the output end of the monitoring protection circuit is connected with the enabling input end of the voltage conversion circuit.
10. The buck switching power supply circuit of claim 9, wherein the feedback output of the voltage conversion circuit regulates the output voltage through a first voltage dividing resistor and a second voltage dividing resistor connected.
CN202210238720.6A 2022-03-11 2022-03-11 Monitoring protection circuit and step-down type switch power supply circuit Active CN114583663B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210238720.6A CN114583663B (en) 2022-03-11 2022-03-11 Monitoring protection circuit and step-down type switch power supply circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210238720.6A CN114583663B (en) 2022-03-11 2022-03-11 Monitoring protection circuit and step-down type switch power supply circuit

Publications (2)

Publication Number Publication Date
CN114583663A true CN114583663A (en) 2022-06-03
CN114583663B CN114583663B (en) 2023-07-21

Family

ID=81781014

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210238720.6A Active CN114583663B (en) 2022-03-11 2022-03-11 Monitoring protection circuit and step-down type switch power supply circuit

Country Status (1)

Country Link
CN (1) CN114583663B (en)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101800467A (en) * 2010-03-11 2010-08-11 Bcd半导体制造有限公司 A kind of protective circuit of Switching Power Supply
US20110128277A1 (en) * 2009-11-27 2011-06-02 Rohm Co., Ltd. Operational amplifier and liquid crystal drive device using same, as well as parameter setting circuit, semiconductor device, and power supply unit
CN109274065A (en) * 2018-11-23 2019-01-25 深圳市道通智能航空技术有限公司 A kind of monitoring circuit, battery and aircraft
CN111327018A (en) * 2020-03-28 2020-06-23 珠海市一微半导体有限公司 Over-current and over-voltage self-locking protection circuit and adapter
CN113495592A (en) * 2020-04-07 2021-10-12 炬芯科技股份有限公司 Short-circuit current protection device and method for LDO (low dropout regulator), and LDO

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110128277A1 (en) * 2009-11-27 2011-06-02 Rohm Co., Ltd. Operational amplifier and liquid crystal drive device using same, as well as parameter setting circuit, semiconductor device, and power supply unit
CN101800467A (en) * 2010-03-11 2010-08-11 Bcd半导体制造有限公司 A kind of protective circuit of Switching Power Supply
CN109274065A (en) * 2018-11-23 2019-01-25 深圳市道通智能航空技术有限公司 A kind of monitoring circuit, battery and aircraft
CN111327018A (en) * 2020-03-28 2020-06-23 珠海市一微半导体有限公司 Over-current and over-voltage self-locking protection circuit and adapter
CN113495592A (en) * 2020-04-07 2021-10-12 炬芯科技股份有限公司 Short-circuit current protection device and method for LDO (low dropout regulator), and LDO

Also Published As

Publication number Publication date
CN114583663B (en) 2023-07-21

Similar Documents

Publication Publication Date Title
US7064533B2 (en) Efficiency improved voltage converter
US7279878B2 (en) Output regulating device for regulating output of electric power source depending on input therefrom
DE102006052016A1 (en) Lighting control device for a lighting device for a vehicle
US20120043951A1 (en) Switching Regulator and Constant On-time Module
EP1718132B1 (en) Load failure protection circuit and discharge lamp driving apparatus
CN103856058A (en) Voltage conversion circuit and voltage conversion controller
CN111474974A (en) Method for improving L DO transient response when sudden change from heavy load to light load or no load
EP0079462A2 (en) Fluorescent lamp safety lighting
US20170034881A1 (en) Boost apparatus with integration of ocp detection and ovp detection
CN114583663A (en) Monitoring protection circuit and step-down switching power supply circuit
EP2690769A1 (en) Power supply circuit
CN111490520A (en) Intelligent instrument and power supply circuit thereof
CN114885463A (en) Linear constant current driving chip and circuit
EP3458930B1 (en) Power supplies with feedback
TWI425755B (en) Pwm buck converter with surge reduction and related method
CN115543059B (en) Processor, processor system and system on chip
CN112350558B (en) Dynamic overshot suppression circuit and suppression method
JP2006238608A (en) Power supply circuit
TWI819827B (en) Output current overshoot prevention circuit for switching power supply circuits
US20240063718A1 (en) Switching power supply circuit and switching power supply system having the same
CN115764811B (en) Short-circuit protection circuit and switching power supply with same
TWI688847B (en) Voltage maintaining circuit
TWI826114B (en) Regulator circuit module and voltage control method
CN217824739U (en) Control circuit of switching power supply and air conditioner
CN117406819A (en) Voltage control circuit and equipment control system

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant