CN114583663B - Monitoring protection circuit and step-down type switch power supply circuit - Google Patents
Monitoring protection circuit and step-down type switch power supply circuit Download PDFInfo
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- CN114583663B CN114583663B CN202210238720.6A CN202210238720A CN114583663B CN 114583663 B CN114583663 B CN 114583663B CN 202210238720 A CN202210238720 A CN 202210238720A CN 114583663 B CN114583663 B CN 114583663B
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- 238000012544 monitoring process Methods 0.000 title claims abstract description 41
- 238000006243 chemical reaction Methods 0.000 claims description 35
- 230000005669 field effect Effects 0.000 claims description 10
- 230000002159 abnormal effect Effects 0.000 abstract description 11
- 230000005856 abnormality Effects 0.000 abstract description 4
- 238000010586 diagram Methods 0.000 description 6
- 238000012423 maintenance Methods 0.000 description 3
- 238000005070 sampling Methods 0.000 description 3
- 230000002411 adverse Effects 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
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- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- 206010033799 Paralysis Diseases 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
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Classifications
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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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- 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
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- 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
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- 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
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Dc-Dc Converters (AREA)
Abstract
The application relates to a monitoring protection circuit and a step-down type 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 monitor 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, the comparison unit outputs a first level to the feedback unit; when the feedback unit is input with the first level, the second level is output to the enabling input end of the monitored circuit so as to stop the monitored circuit. The utility model provides a monitor protection circuit that contains comparison unit and feedback unit carries out real-time supervision and feedback to being monitored the circuit, avoids leading to by the abnormal condition of output voltage of monitored the circuit because of bleeder resistor inefficacy or is unusual, protects the back end circuit, reduces components and parts or the risk of board card burning, reduces the influence of output voltage abnormality.
Description
Technical Field
The application relates to the technical field of electronic circuits, in particular to a monitoring protection circuit and a step-down type switching power supply circuit.
Background
The power supply requirements of a main board and other boards in the server are low voltage and high current, so that a step-down type switching power supply scheme is adopted. The basic circuit of the step-down type switching power supply consists of a primary rectifying and filtering circuit, an energy storage inductor, a secondary filtering capacitor, a voltage conversion circuit, a sampling and feedback circuit and the like, and the key of realizing the stable operation of each board card in the server is that the high voltage is converted into the low voltage and the output is stabilized.
In conventional implementations, the output voltage is generally regulated by monitoring the voltage-dividing resistor voltage, but the effectiveness of the method depends on the performance of the voltage-dividing resistor, and the failure of the voltage-dividing resistor during application can lead to some adverse effects. For example, when the voltage dividing resistor fails, it may cause the output voltage of the voltage conversion circuit to be continuously increased or the output voltage of the voltage conversion circuit to be continuously decreased. The continuous increase of the output voltage can negatively affect the stability of the power supply circuit of the board, and may burn back-end chips, components, loads and the like, or even cause the burning of the whole board or the server, resulting in serious economic loss. Continuously reducing the output voltage can cause that the back-end circuit cannot work normally, and part of the board card power supply links are in a paralysis state, so that the normal operation of the load is seriously affected.
Disclosure of Invention
Aiming at the problems in the prior art, the application provides a monitoring protection circuit and a step-down type switching power supply circuit so as to cope with the conditions of abnormal voltage output and influence on a rear-end circuit.
Specifically, the embodiment of the invention provides the following technical scheme:
in a first aspect, a monitoring protection circuit is provided, an input end of the monitoring protection circuit is connected with a monitored voltage output end of a monitored circuit, and an output end of the monitoring protection circuit is connected with an enabling input end of the monitored circuit; the monitor 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 the first level, the second level is output to the enabling input end of the monitored circuit so as to stop the monitored circuit.
According to one possible implementation in an embodiment of the present application, the first level and the second level are on average low.
According to one implementation manner in the embodiments of the present application, the comparing unit includes: a first operational amplifier and a second operational amplifier;
the reverse input end of the first operational amplifier is connected to the monitored voltage output end, the input voltage of the same-direction 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 in the embodiments of the present application, the feedback unit is an and gate logic unit.
According to one implementation manner in the embodiments of the present application, the monitoring protection circuit further includes: a power supply unit; the power supply unit comprises a field effect transistor; 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 electrode power supply.
According to one implementation manner in the embodiments of the present application, the monitoring protection circuit further includes: an alarm unit; and 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 is carried out.
According to an implementation manner in the embodiments of the present application, the alarm unit includes: a NOT logic unit and an indicator light; the input end of the NOT logic unit is connected with the output end of the feedback unit, and the output end of the NOT logic unit is connected with the indicator lamp.
According to one implementation of the embodiments 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 monitor protection circuit described in the first aspect; the voltage conversion circuit converts the 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 one implementation manner in the embodiments of the present application, the feedback output end of the voltage conversion circuit adjusts the output voltage through the connected first voltage dividing resistor and second voltage dividing resistor.
According to the technical content provided by the embodiment of the application, the monitoring protection circuit comprising the comparison unit and the feedback unit 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, when the voltage value output by the monitored voltage output end is abnormal, the voltage value is fed back to the monitored circuit, the monitored circuit stops working, the monitored circuit can be monitored and fed back in real time, the abnormal output voltage of the monitored circuit caused by the failure or abnormality of the voltage dividing resistor is effectively avoided, the back-end circuit is further protected, the risk of burning of the back-end such as components or boards is reduced, the influence range of the monitored voltage abnormality is reduced, and the economic loss is reduced.
Drawings
FIG. 1 is a schematic circuit diagram of a monitor protection circuit provided in one embodiment;
FIG. 2 is a circuit diagram of a monitor protection circuit according to one embodiment;
FIG. 3 is a circuit diagram of a buck switching power supply circuit according to one embodiment;
Detailed Description
The present application will be described in further detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the present application.
Fig. 1 is a schematic circuit diagram of a monitoring protection circuit provided in an embodiment of the present application, as shown in fig. 1, an input end of a monitoring protection circuit 1 provided in the present application is connected to a monitored voltage output end of a monitored circuit 2, and an output end of the monitoring protection circuit 1 is connected to an enable input end of the monitored circuit 2; the monitor protection circuit 1 includes: a comparing 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 if the voltage value output by the monitored voltage output end exceeds the voltage range, the comparison unit outputs a first level to the feedback unit 12; when the feedback unit 12 is inputted with the first level, it outputs the second level to the enable input terminal of the monitored circuit 2, so that the monitored circuit 2 stops operating.
Specifically, the input end of the monitoring protection circuit 1 is connected to the monitored voltage output end of the monitored circuit 2, the output end of the monitoring protection circuit 1 is connected to the enable input end of the monitored circuit 2, wherein the enable input end can control the working state of the monitored circuit 2, the output voltage of the output end of the monitored circuit 2 has a normal working voltage range when the monitored circuit works normally, the voltage range is preset for the comparison unit 11, the voltage value output by the monitored voltage output end is compared with the preset voltage range, if the voltage value output by the monitored voltage output end exceeds the preset voltage range, the monitored circuit 2 is abnormal, the first level is output to the feedback unit 12, when the feedback unit 12 is input to the first level, the second level is fed back to the enable input end of the monitored circuit 2, and the enable input end of the monitored circuit 2 can control the monitored circuit 2 to stop working when the second level is input, so that real-time monitoring and protection of the monitored circuit 2 can be realized.
As an implementation manner, if the enable input of the monitored circuit 2 is active high, the first level and the second level are low on average. As another implementation manner, if the enable input of the monitored circuit 2 is active low, the first level and the second level are both high. The following embodiments will be described taking the case where the first level and the second level are low levels as an example.
Fig. 2 is a circuit configuration diagram of a monitor protection circuit according to an embodiment of the present application, and the monitor protection circuit is described in detail below according to fig. 2 and in combination with an embodiment.
According to one possible implementation in the embodiment of the present application, the comparing unit 11 includes two operational amplifiers: a first operational amplifier a and a second operational amplifier B. Here, the expressions "first", "second", and the like in the embodiments of the present application do not have any meaning in terms of order, size, and number, and are merely used to distinguish between them by name. For example, the first operational amplifier and the second operational amplifier are only used to distinguish the two operational amplifiers by name.
The reverse 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 same-direction input end of the first operational amplifier A is set to be the highest value of a 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 same-direction input end of the second operational amplifier B is connected to the monitored voltage output end, the input voltage of the reverse input end of the second operational amplifier B is set to 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 12.
Specifically, the reverse input end of the first operational amplifier a is connected to the monitored voltage output end, and the input voltage of the same-direction input end of the first operational amplifier a is set to the highest value of the preset voltage range, so that when the output voltage of the monitored voltage output end is abnormally increased and exceeds the maximum value of the working 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 a low level. The outputs of the first and second operational amplifiers a and B are both connected to the input of the feedback unit 12. Therefore, when the output voltage is abnormally increased or abnormally decreased, the feedback unit 12 is input with a low level.
According to one implementation in 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 a low level to the enable input terminal of the monitored circuit 2. An Enable (EN) input, also called an Enable or chip select, is an input of a control signal for controlling the operating state of the monitored circuit 2. The enable input is normally active high, i.e. the monitored circuit 2 enters an active state when the enable input is high. Therefore, in this embodiment, when the and gate logic unit outputs a low level to the enable input terminal of the monitored circuit 2, the enable input terminal stops working, thereby achieving the purpose of protecting the circuit.
According to one possible 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 for supplying power to the first operational amplifier a and the second operational amplifier B.
According to one possible implementation in the embodiment of the present application, the power supply unit 13 includes a field effect transistor; the gate of the field effect transistor is connected to the Power Good output end of the monitored circuit 2, the source is connected to the Power input ends of the first operational amplifier and the second operational amplifier, and the drain is connected to the drain Power supply.
According to one possible 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 with the output end of the feedback unit 12, and alarms when the feedback unit 12 outputs a low level.
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 alarms in a manner of lighting, ringing, and the like, so that convenience can be provided for maintenance personnel to troubleshoot, the fault can be locked quickly, and the loss can be reduced.
According to one implementation manner in this embodiment of the present application, as shown in fig. 2, the alarm unit 14 includes a not gate logic unit and an indicator lamp, 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 lamp, when an abnormal output voltage of the monitored circuit 2 exists, the feedback unit 12 outputs a low level, and when the output end of the not gate logic unit is input with the low level, the output end of the not gate logic unit outputs a high level to the indicator lamp, so that the indicator lamp is turned on to give an alarm, and convenience is provided for maintenance personnel to troubleshoot.
According to one possible implementation in an 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 high current, so that the voltage conversion circuit is mostly adopted for supplying power, and the stability of the output voltage of the voltage conversion circuit is the key for realizing the stable operation of each board in the server, so that as one application scenario, the monitored circuit 2 in the embodiment can comprise the voltage conversion circuit for monitoring the feedback voltage of the voltage conversion circuit. The monitoring protection circuit 1 can also be applied to the power supply circuit monitoring of various mainboards and other boards in the server.
According to the specific embodiment provided by the application, the technical scheme provided by the application can have the following advantages:
the utility model provides a through providing a control protection circuit that contains comparison unit and feedback unit, be connected with the voltage output of being monitored circuit, to be compared by the output voltage of being monitored circuit and preset voltage range, feedback is given by the monitored circuit when output voltage is unusual, make by the monitored circuit stop work, can carry out real-time supervision and feedback to the monitored circuit, effectively avoid leading to by the abnormal condition of the output voltage of monitored circuit because of bleeder resistor inefficacy or abnormality, and then protection back end circuit, reducible components and parts or the risk of board card burning out, reduce the influence scope of output voltage inefficacy, reduce economic loss.
It is to be understood that not necessarily all of the above-described advantages may be achieved simultaneously in practicing any one of the methods or articles of manufacture of 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 monitor 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 switching circuit, the second voltage is lower than the first voltage, i.e., the high voltage is converted into a 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 enabling input end of the voltage conversion circuit 3.
Specifically, in the step-down switching power supply circuit, a circuit to be monitored in real time is a voltage conversion circuit 3, and the voltage conversion circuit 3 is connected to the monitor protection circuit 1 as the monitored circuit 2 in the above-described 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 of the voltage conversion circuit 3, namely an FB pin; the output end of the monitoring protection circuit 1 is connected with the enabling input end of the voltage conversion circuit 3, namely an EN pin. Therefore, the problem that when the voltage conversion circuit 3 of the step-down type switching power supply circuit fails, such as a voltage dividing resistor is short-circuited or broken, the output voltage is continuously increased or the output voltage is lower than a target value can be solved.
According to one possible implementation manner in the embodiment of the present application, the feedback output end 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 of the voltage conversion circuit 3, i.e., FB pin, regulates the output Voltage (VOUT) through the connected first voltage dividing resistor R1 and second voltage dividing resistor R2. Currently, in the buck-type switching power supply scheme, the Voltage conversion circuit 3 may be disposed in a VR (Voltage regulated) chip. The VR chip is provided with a FB feedback pin, and voltage dividing resistors R1 and R2 are connected to the pin to adjust output voltage. In practical application, reference voltage V in the chip is required to be referenced ref According to V ref Voltage dividing resistors R1 and R2 with proper resistance value are selected by the ratio of (VOUT.R2/(R1+R2), and the voltage of the second voltage dividing resistor, namely the voltage across the resistor R2 is monitored and is matched with V ref And comparing, enabling the output voltage to reach a target value and stably outputting. In the step-down switching power supply scheme, the reliability of the voltage dividing resistor plays a decisive role in realizing stable output of output voltage. When the voltage dividing resistor fails, the VR chip should timely obtain signals in the state to react, so that serious influence on a rear-end circuit and a load is avoided.
In combination with the implementation of the above embodiment, the following is used to output voltage1.2. 1.2V, V ref For example, a chip scheme of 0.6V is used to describe the embodiments of the present application, including the following:
1) The resistance values of the upper voltage dividing resistor R1 and the lower voltage dividing resistor R2 are set to be 10k omega, and the voltage at two ends of the second voltage dividing resistor R2 is taken as the sampling voltage V under the assumption that the output voltage is allowed to fluctuate by 10 percent up and down, namely the normal output voltage range is 1.08-1.32V m Sampling voltage V m Ranging from 0.54 to 0.66V;
2) Setting V of operational amplifier A ref1 Set the V of the operational amplifier B to 0.66V ref2 0.54V;
3) After power-on, VOUT normally outputs, when VOUT output reaches the preset proportion (for example, 90%) of target voltage, PG signal, namely power source normal signal is pulled up, MOS 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, V m Reducing to 0; the operational amplifier A outputs high level, the operational amplifier B outputs low level, the logic unit outputs low level through the AND gate, the enable input end EN is input with low level, and the voltage conversion circuit stops voltage output; the low level is converted to high level via the not gate logic unit and the LED indicator lights are lit.
5) When the second voltage dividing resistor R2 is disconnected or the first voltage dividing resistor R1 is short-circuited, V m Abnormal enlargement; the operational amplifier A outputs low level, the operational amplifier B outputs high level, the logic unit outputs low level through the AND gate, the enable input end EN is input with low level, and the voltage conversion circuit stops voltage output; the low level is converted to high level via the not gate logic unit and the LED indicator lights are lit.
As can be seen from the above examples, when the first voltage dividing resistor R1 or the second voltage dividing resistor R2 fails, the first voltage dividing resistor R1 or the second voltage dividing resistor R2 can be monitored in time and fed back to the monitored circuit through the monitoring protection circuit, so that the monitored circuit stops working, adverse effects on a circuit at the rear end of the monitored circuit, such as a component or a board card connected with 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 locked quickly.
In addition, fig. 3 illustrates a step-down switching power supply circuit as an example, and the monitoring protection circuit provided in the present application may be applied to other application scenarios to realize monitoring and protection of the monitored circuit, which is not listed here.
It should be noted that, each of the above embodiments of the present application takes a scenario in which the enable input is active high as an example. In another embodiment of the present application, when the enable input of the monitored circuit is active low, the principle of the monitoring protection circuit is unchanged, and the specific structure can be implemented by slightly changing the principle of the above embodiment. For example, the same-direction input terminal of the first operational amplifier a is connected to the monitored voltage output terminal of the monitored circuit 2, the input voltage of the reverse input terminal of the first operational amplifier a is set to the highest value of the preset voltage range, and the output terminal of the first operational amplifier a is connected to the input terminal of the feedback unit; the reverse input end of the second operational amplifier B is connected to the monitored voltage output end, the input voltage of the same-direction input end of the second operational amplifier B is set to be the lowest value of a 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 employ, for example, an or gate logic unit. When the feedback unit is input with high level, the feedback unit outputs high level to the enabling input end of the monitored circuit, so that the monitored circuit stops working. In this case, the alarm unit may include an indicator lamp connected to an output terminal of the or gate logic unit, and the indicator lamp is turned on to alarm in case that the or gate logic unit outputs a high level.
The same and similar parts of the above embodiments are all referred to each other, and each embodiment focuses on the differences from the other embodiments.
The circuits referred to in the above embodiments of the present application may be general circuits, may also be in the form of integrated chips, or the like, and the present application is not limited thereto.
The above embodiments do not limit the scope of the application. It will be apparent to those skilled in the art that various modifications, combinations, sub-combinations and alternatives are possible, depending on design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application are intended to be included within the scope of the present application.
Claims (9)
1. The monitoring protection circuit is characterized in that an input end of the monitoring protection circuit is connected with a monitored voltage output end of a monitored circuit, and an output end of the monitoring protection circuit is connected with an enabling input end of the monitored circuit; the monitor 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, wherein the comparison unit comprises: the input voltage of the same-direction input end of the first operational amplifier is set to be the highest value of the preset voltage range, 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, so that when the output voltage of the monitored voltage output end is abnormally increased and exceeds the highest value of the preset voltage range, the first operational amplifier outputs a low level, and when the output voltage of the monitored voltage output end is abnormally reduced and exceeds the lowest value of the preset voltage range, the second operational amplifier outputs a low level;
when the feedback unit is input with the first level, the second level is output to the enabling input end of the monitored circuit so as to stop the monitored circuit.
2. The monitor protection circuit of claim 1 wherein said first level and said second level are on average low.
3. The monitor protection circuit of claim 1, wherein the feedback unit is an and gate logic unit.
4. The monitor protection circuit of claim 1, wherein the monitor protection circuit further comprises: a power supply unit;
the power supply unit comprises a field effect transistor; 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 electrode power supply.
5. The monitor protection circuit of claim 1, wherein the monitor protection circuit further comprises: an alarm unit;
and 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 is carried out.
6. The monitor protection circuit according to claim 5, wherein the alarm unit comprises: a NOT logic unit and an indicator light; the input end of the NOT logic unit is connected with the output end of the feedback unit, and the output end of the NOT logic unit is connected with the indicator lamp.
7. The monitor protection circuit according to any one of claims 1 to 6, wherein the monitored circuit comprises a voltage conversion circuit.
8. A step-down switching power supply circuit, characterized in that the step-down switching power supply circuit comprises a voltage conversion circuit and a monitor protection circuit as claimed in any one of claims 1 to 7;
the voltage conversion circuit converts the 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.
9. The buck switching power supply circuit according to claim 8, wherein the feedback output terminal of the voltage conversion circuit regulates the output voltage via the connected first and second voltage dividing resistors.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
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| CN202210238720.6A CN114583663B (en) | 2022-03-11 | 2022-03-11 | Monitoring protection circuit and step-down type switch power supply circuit |
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| CN114583663B true CN114583663B (en) | 2023-07-21 |
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Citations (4)
| 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 |
| 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 |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5702570B2 (en) * | 2009-11-27 | 2015-04-15 | ローム株式会社 | Operational amplifier, liquid crystal driving device using the same, parameter setting circuit, semiconductor device, and power supply device |
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Patent Citations (4)
| 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 |
| 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 |
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| CN114583663A (en) | 2022-06-03 |
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