CN115173365B - Control method of overvoltage protection device and overvoltage protection device - Google Patents
Control method of overvoltage protection device and overvoltage protection device Download PDFInfo
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- CN115173365B CN115173365B CN202210899966.8A CN202210899966A CN115173365B CN 115173365 B CN115173365 B CN 115173365B CN 202210899966 A CN202210899966 A CN 202210899966A CN 115173365 B CN115173365 B CN 115173365B
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- 238000000034 method Methods 0.000 title claims abstract description 10
- 238000011084 recovery Methods 0.000 claims abstract description 33
- 238000012544 monitoring process Methods 0.000 claims abstract description 21
- 230000004044 response Effects 0.000 claims abstract description 7
- 239000003990 capacitor Substances 0.000 claims description 32
- 238000004590 computer program Methods 0.000 claims description 6
- 238000010586 diagram Methods 0.000 description 6
- 230000006870 function Effects 0.000 description 3
- 238000007599 discharging Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000002093 peripheral effect Effects 0.000 description 2
- 230000007547 defect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000036039 immunity Effects 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
Classifications
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- 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
- H02H3/20—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 excess voltage
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H1/00—Details of emergency protective circuit arrangements
- H02H1/0061—Details of emergency protective circuit arrangements concerning transmission of signals
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H1/00—Details of emergency protective circuit arrangements
- H02H1/0092—Details of emergency protective circuit arrangements concerning the data processing means, e.g. expert systems, neural networks
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- 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
- H02H3/20—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 excess voltage
- H02H3/207—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 excess voltage also responsive to under-voltage
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- Emergency Protection Circuit Devices (AREA)
- Protection Of Static Devices (AREA)
Abstract
The invention discloses a control method of an overvoltage protection device and the overvoltage protection device. The overvoltage protection device includes: the acquisition circuit is used for acquiring the voltage of the input end, the overvoltage protection threshold voltage and the undervoltage protection threshold voltage; the monitoring circuit is used for outputting a first level signal under the condition that the falling rate of the voltage of the input end is larger than a preset rate; a first switch; and the control circuit is used for controlling the first switch to be turned on when the voltage of the input end rises to be higher than the undervoltage protection threshold voltage and lower than the overvoltage protection threshold voltage, and controlling the first switch to be turned off when the voltage of the input end rises to be higher than the overvoltage protection threshold voltage; controlling the first switch to be turned on when the voltage drops below the overvoltage recovery threshold voltage and above the undervoltage protection threshold voltage, and controlling the first switch to be turned off when the voltage drops below the undervoltage protection threshold voltage; the output terminal is disabled from outputting a signal in response to the first level signal to avoid a short pulse at the output terminal.
Description
Technical Field
The invention relates to the technical field of overvoltage protection, in particular to a control method of an overvoltage protection device and the overvoltage protection device.
Background
Overvoltage protection devices are typically located in the input power supply path to protect the following circuits from overvoltages and/or overcurrents. The protection function of most overvoltage protection devices is now quite simple, if the voltage Vin at the input is greater than the overvoltage protection threshold voltage Vovp, the switch in series in the power supply path between the input and the output is opened, and the output is now voltage-free. If the voltage Vin at the input is less than the overvoltage recovery threshold voltage Vovp _recovery, then the switch in series in the power supply path between the input and the output is closed. At this time, the output terminal has a voltage, and the voltage Vout at the output terminal is equal to the voltage Vin at the input terminal minus a small internal voltage drop.
Although this design may achieve the basic overvoltage protection function. In some cases, the pulses at the output may be very narrow, which may confuse the electrical system for such abnormally short pulses. As shown in fig. 1 and 2, when the voltage Vin at the input terminal is greater than the overvoltage protection threshold voltage Vovp, the voltage at the output terminal is absent. At this time, if the voltage Vin at the input terminal is removed, for example, the power supply of the device is turned off, the voltage Vin at the input terminal must inevitably drop below the overvoltage recovery threshold voltage Vovp _recovery. The output will rise from the 0-Vin level in a very short time, as defined by the simple internal comparator logic. As the voltage Vin at the input continues to drop, the voltage Vout at the output will quickly drop from Vin to 0 and will reach the under-voltage protection threshold voltage Vuvlo of the IC (i.e., the over-voltage protection device). Once Vin < Vuvlo, the IC will not be able to maintain normal operation and will stop all functions. The length of the short pulse depends on the size of the input capacitance, the size of the output capacitance and the rate of change of the voltage Vin at the input, which can be as short as a few microseconds.
Such short pulses are undesirable in electrical system designs, particularly in high-end designs. The momentary decrease of the voltage Vin at the input leads to a short pulse of the voltage Vout at the output. Short pulses are of no value to the electrical system, since the voltage Vin at the input is quickly removed, and the short pulses cause the second stage to start unnecessarily and shut down after the short pulses. It follows that the short pulses reduce the reliability and lifetime of the electrical system.
Disclosure of Invention
The invention aims to overcome the defect that the output end of a power supply path is short-pulse due to the existing overvoltage protection device, so that the reliability and the service life of an electrical system are reduced.
The invention solves the technical problems by the following technical scheme:
The first aspect of the invention provides an overvoltage protection device, comprising an acquisition circuit, a monitoring circuit, a control circuit and a first switch connected in series between an input end and an output end;
The acquisition circuit is used for acquiring the voltage of the input end, the overvoltage protection threshold voltage and the undervoltage protection threshold voltage;
the monitoring circuit is used for monitoring the falling rate of the voltage of the input end and outputting a first level signal under the condition that the falling rate is larger than a preset rate;
The control circuit is used for controlling the first switch to be turned on when the voltage of the input end rises to be higher than the undervoltage protection threshold voltage and lower than the overvoltage protection threshold voltage, and controlling the first switch to be turned off when the voltage of the input end rises to be higher than the overvoltage protection threshold voltage; and
Controlling the first switch to be turned on when the voltage of the input end is reduced to be lower than an overvoltage recovery threshold voltage and higher than the undervoltage protection threshold voltage, and controlling the first switch to be turned off when the voltage of the input end is reduced to be lower than the undervoltage protection threshold voltage; and
Disabling the output from outputting a signal in response to the first level signal;
The under-voltage protection threshold voltage is smaller than the over-voltage recovery threshold voltage, and the over-voltage recovery threshold voltage is smaller than the over-voltage protection threshold voltage.
Optionally, the monitoring circuit is specifically configured to output the first level signal when the decrease rates monitored for consecutive preset times are all greater than a preset rate.
Optionally, the control circuit is further configured to start timing in response to the first level signal and stop timing after a period of time;
The control circuit is specifically configured to allow the output terminal to output a signal after stopping the timing.
Optionally, the monitoring circuit includes a second switch, a third switch, a current source, a capacitor, and a comparator;
One end of the second switch is used for receiving the voltage of the input end, and the other end of the second switch is connected with one end of the capacitor and one end of the third switch respectively; the other end of the capacitor is grounded; the other end of the third switch is connected with the current source, and the control end of the second switch and the control end of the third switch are both connected with the control circuit; wherein the second switch and the third switch are not turned on at the same time;
One end of the comparator is connected with one end of the capacitor, the other end of the comparator is used for receiving the voltage of the input end, and the output end of the comparator is connected with the control circuit and is used for outputting the first level signal under the condition that the voltage of the input end is smaller than the voltage of one end of the capacitor;
And the voltage of the current source and the capacitance value of the capacitor are determined according to the preset speed.
Optionally, the monitoring circuit further comprises a fourth switch, one end of the comparator is connected with one end of the capacitor through the fourth switch, and a control end of the fourth switch is connected with the control circuit; wherein the fourth switch and the second switch are not turned on at the same time.
Optionally, the control circuit is specifically configured to control the first switch to be turned on or off for a period of time.
A second aspect of the present invention provides a control method of an overvoltage protection device, comprising the steps of:
Acquiring the voltage of an input end, an overvoltage protection threshold voltage and an undervoltage protection threshold voltage;
If the voltage of the input end rises to be higher than the undervoltage protection threshold voltage and lower than the overvoltage protection threshold voltage, controlling a first switch connected in series between the input end and the output end to be turned on, and if the voltage of the input end rises to be higher than the overvoltage protection threshold voltage, controlling the first switch to be turned off;
Controlling the first switch to be turned on if the voltage of the input end is reduced to be lower than the overvoltage recovery threshold voltage and higher than the undervoltage protection threshold voltage, and controlling the first switch to be turned off if the voltage of the input end is reduced to be lower than the undervoltage protection threshold voltage;
If the falling rate of the voltage of the input end is larger than the preset rate, the output end is forbidden to output signals;
The under-voltage protection threshold voltage is smaller than the over-voltage recovery threshold voltage, and the over-voltage recovery threshold voltage is smaller than the over-voltage protection threshold voltage.
A third aspect of the invention provides an overvoltage protection device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, the processor implementing the control method according to the second aspect when executing the computer program.
A fourth aspect of the invention provides an electronic device comprising an overvoltage protection device as described in the first or third aspect.
A fifth aspect of the invention provides a chip comprising an overvoltage protection device as described in the first or third aspect.
On the basis of conforming to the common knowledge in the art, the optional conditions can be arbitrarily combined to obtain the preferred embodiments of the invention.
The invention has the positive progress effects that: if the falling rate of the voltage of the input end is larger than the preset rate, the condition that the voltage of the input end is removed, namely continuous power failure occurs, such as power supply shutdown, is indicated, at the moment, short pulses which are unfavorable for an electrical system can be avoided at the output end by prohibiting the output signal of the output end, and not only can the reliability of the overvoltage protection device be improved, but also the reliability and the service life of the electrical system can be improved.
Drawings
Fig. 1 is a schematic diagram of the circuit connection of the overvoltage protection device in the power path in the prior art.
Fig. 2 is a schematic diagram showing the comparison of the voltage at the input terminal and the voltage at the output terminal in fig. 1.
Fig. 3 is a schematic circuit connection diagram of the overvoltage protection device provided in embodiment 1 of the present invention in a power supply path.
Fig. 4 is a schematic diagram of an internal structure of a monitoring circuit according to embodiment 1 of the present invention.
Fig. 5 is a comparison schematic diagram of control signals P1, P2 and P3 provided in embodiment 1 of the present invention.
Detailed Description
The invention is further illustrated by means of the following examples, which are not intended to limit the scope of the invention.
Example 1
As shown in fig. 3, the embodiment provides an overvoltage protection device, which includes an acquisition circuit, a monitoring circuit, a control circuit, and a first switch connected in series between an input terminal and an output terminal.
The acquisition circuit is used for acquiring the voltage Vin, the overvoltage protection threshold voltage Vovp and the undervoltage protection threshold voltage Vuvlo of the input end. In implementations, the over-voltage protection threshold voltage Vovp and the under-voltage protection threshold voltage Vuvlo may be determined from the collected voltage Vin at the input. In a specific example, the overvoltage protection threshold voltage Vovp and the undervoltage protection threshold voltage Vuvlo may be obtained according to the voltage Vin of the input terminal by providing a voltage dividing resistor between the input terminal and the ground terminal.
The monitoring circuit is used for monitoring the falling rate of the voltage Vin of the input end and outputting a first level signal under the condition that the falling rate is larger than a preset rate. In a specific implementation, the preset rate is set according to practical situations, and may be set to 100V/s, for example.
The control circuit is used for controlling the first switch connected in series between the input end and the output end to be turned on when the voltage Vin of the input end rises to be higher than the undervoltage protection threshold voltage Vuvlo and lower than the overvoltage protection threshold voltage Vovp, and controlling the first switch to be turned off when the voltage Vin of the input end rises to be higher than the overvoltage protection threshold voltage Vovp.
The control circuit is further configured to control the first switch to be turned on when the voltage Vin at the input terminal falls below the overvoltage recovery threshold voltage Vovp _recovery and above the undervoltage protection threshold voltage Vuvlo, and to control the first switch to be turned off when the voltage at the input terminal falls below the undervoltage protection threshold voltage Vuvlo. Wherein, the undervoltage protection threshold voltage Vuvlo is less than the overvoltage recovery threshold voltage Vovp _recovery, and the overvoltage recovery threshold voltage Vovp _recovery is less than the overvoltage protection threshold voltage Vovp. The overvoltage recovery threshold voltage Vovp _recovery may be set according to the actual situation.
The control circuit is further configured to disable the output from outputting a signal in response to the first level signal. The first level signal may be a low level signal or a high level signal, and may also be a falling edge signal or a rising edge signal. In a specific implementation, disabling the output terminal from outputting the signal may be implemented by disabling an output pin.
In this embodiment, if the falling rate of the voltage at the input end is greater than the preset rate, it is indicated that the voltage at the input end is being removed, i.e. the voltage at the input end is continuously powered down, for example, the power is turned off, and at this time, by prohibiting the output signal from the output end, the output end can be prevented from generating a short pulse which is unfavorable for the electrical system, so that the reliability of the overvoltage protection device can be improved, and the reliability and the service life of the electrical system in which the overvoltage protection device is located can also be improved.
The first switch in this embodiment may be a switching device such as a MOS transistor or a triode, or may be a switching chip. If the first switch is turned on, the path between the input end and the output end is turned on, the output end has voltage output, and the voltage Vout at the output end is specifically the voltage Vin at the input end minus the internal voltage drop of the first switch. If the first switch is turned off, the path between the input end and the output end is disconnected, and no voltage is output from the output end, i.e. the voltage Vout of the output end is about 0V.
The control circuit may control the first switch to be turned on by outputting a high level signal to the first switch, and control the first switch to be turned off by outputting a low level signal to the first switch. The control circuit can also control the first switch to be turned on by outputting a low-level signal to the first switch, and control the first switch to be turned off by outputting a high-level signal to the first switch. In particular, the type of the first switch and the peripheral circuit of the first switch may be determined.
In an alternative embodiment, the monitoring circuit includes a second switch, a third switch, a current source, a capacitor, and a comparator. One end of the second switch is used for receiving the voltage of the input end, and the other end of the second switch is connected with one end of the capacitor and one end of the third switch respectively; the other end of the capacitor is grounded; the other end of the third switch is connected with the current source, and the control end of the second switch and the control end of the third switch are both connected with the control circuit; wherein the second switch and the third switch are not turned on at the same time.
One end of the comparator is connected with one end of the capacitor, the other end of the comparator is used for receiving the voltage of the input end, and the output end of the comparator is connected with the control circuit and used for outputting the first level signal under the condition that the voltage of the input end is smaller than the voltage of one end of the capacitor.
And the voltage of the current source and the capacitance value of the capacitor are determined according to the preset speed.
In this embodiment, if the second switch is turned on and the third switch is turned off, the capacitor is in a discharge state, and if the second switch is turned off and the third switch is turned on, the capacitor is in a charge state, and the capacitor is charged by a current source. By comparing the voltages of the two input ends of the comparator, the falling rate of the voltage of the input ends can be compared with the preset rate.
In order to improve accuracy of the first level signal output by the comparator, in an alternative implementation manner, the monitoring circuit further comprises a fourth switch, one end of the comparator is connected with one end of the capacitor through the fourth switch, and a control end of the fourth switch is connected with the control circuit. Wherein the fourth switch and the second switch are not turned on at the same time. When the second switch is turned on, the capacitor is in a discharging state, at the moment, the fourth switch is turned off, the voltage at one end of the comparator connected with the fourth switch is always 0V, and interference to the output end of the comparator is avoided.
In this embodiment, the second switch, the third switch, and the fourth switch may be switching devices such as MOS transistors and triodes, or may be switching chips.
In a specific example, as shown in fig. 4, one end of the second switch receives the voltage Vin of the input terminal through the resistor R1, and is connected to the ground terminal through the resistor R2. The other end of the second switch is respectively connected with one end of the capacitor C1, one end of the third switch and one end of the fourth switch. The other end of the capacitor C1 is grounded, and the other end of the third switch is connected with a current source. The non-inverting input end of the comparator is connected with one end of the capacitor C1 through the fourth switch, and the inverting input end receives the voltage of the input end through the resistor R1.
In this example, if the second switch is turned off and the third switch and the fourth switch are both turned on, the voltages V1 and V2 across the comparator are compared. If V1 is greater than or equal to V2, it is indicated that the falling rate of the voltage Vin at the input terminal does not exceed the preset rate. If V1 is smaller than V2, it indicates that the falling rate of the voltage Vin at the input end exceeds the preset rate, and the output end Vout' of the comparator outputs a high-level signal, i.e. a first-level signal. If the second switch is turned on and the third switch and the fourth switch are turned off, the voltage V2 at the non-inverting input terminal of the comparator is 0, and the voltage V1 at the inverting input terminal is greater than V2, and the output terminal Vout' of the comparator outputs a low level signal.
As shown in fig. 4, the control circuit outputs control signals P1, P2 and P3 to the control terminals of the second switch, the third switch and the fourth switch, respectively. Fig. 5 is a schematic diagram for illustrating one control signal P1, P2 and P3. In this example, a high level of the control signal indicates that the corresponding switch is on, and a low level of the control signal indicates that the corresponding switch is off. As can be seen from fig. 4 and 5, the second switch is controlled to be turned on first, and the third switch and the fourth switch are both turned off, at which time the capacitor C1 is in a discharge state. Then, the second switch is controlled to be turned off and the third switch is controlled to be turned on, and the capacitor C1 is in a charging state. Before the third switch is controlled to be turned off, the fourth switch is controlled to be turned on, and whether the falling rate of the voltage at the input end exceeds the preset rate can be obtained by comparing the voltages V1 and V2 at the two ends of the comparator. And finally, controlling the third switch and the fourth switch to be switched off, and controlling the second switch to be switched on, wherein the capacitor C1 is in a discharging state.
In order to further increase the reliability of the overvoltage protection device, in an alternative embodiment, the monitoring circuit is specifically configured to output the first level signal if the decrease rates monitored for consecutive preset times are all greater than a preset rate. The preset times may be set according to actual situations, for example, may be set to 3 times.
In a specific implementation, the monitoring circuit may further include a counter, where an output end of the comparator is configured to output a second level signal when the voltage of the input end is smaller than the voltage of one end of the capacitor, and the counter is configured to count one time in response to the second level signal, and output the first level signal when the count number reaches a preset number. That is, the first level signal is output to the control circuit to prohibit the output of the signal to the first switch in the case where the counter receives the second level signal a preset number of times.
In an alternative embodiment, the control circuit is further configured to start timing in response to the first level signal and stop timing after a period of time; the control circuit is specifically configured to allow the output terminal to output a signal after stopping the timing. In a specific implementation, the enabling of the output to output the signal may be implemented by enabling an output pin.
In an implementation, the control circuit may include a timer that stops counting after a period of time has elapsed. Wherein, the period of time can be set according to actual conditions.
In this embodiment, after the output terminal is allowed to output a signal, the first switch is controlled to be turned on when the voltage of the input terminal rises to be higher than the undervoltage protection threshold voltage and lower than the overvoltage protection threshold voltage, and the output terminal normally outputs the signal.
In order to avoid fluctuations in the output voltage and to increase the anti-interference capability of the overvoltage protection device with respect to spurious noise, in an alternative embodiment the control circuit is specifically configured to control the first switch to be turned on or off for a time delay.
Example 2
The embodiment provides a control method of an overvoltage protection device, which comprises the following steps:
S1, acquiring the voltage Vin of an input end, an overvoltage protection threshold voltage Vovp and an undervoltage protection threshold voltage Vuvlo. In implementations, the over-voltage protection threshold voltage Vovp and the under-voltage protection threshold voltage Vuvlo may be determined from the voltage Vin at the input. In a specific example, the overvoltage protection threshold voltage Vovp and the undervoltage protection threshold voltage Vuvlo may be obtained according to the voltage Vin of the input terminal by providing a voltage dividing resistor between the input terminal and the ground terminal.
S2, if the voltage Vin of the input end rises to be higher than the undervoltage protection threshold voltage Vuvlo and lower than the overvoltage protection threshold voltage Vovp, the first switch connected in series between the input end and the output end is controlled to be turned on, and if the voltage Vin of the input end rises to be higher than the overvoltage protection threshold voltage Vovp, the first switch is controlled to be turned off.
And S3, controlling the first switch to be turned on if the voltage Vin of the input end falls below the overvoltage recovery threshold voltage Vovp _recovery and is higher than the undervoltage protection threshold voltage Vuvlo, and controlling the first switch to be turned off if the voltage Vin of the input end falls below the undervoltage protection threshold voltage Vuvlo.
S4, if the falling rate of the voltage Vin of the input end is larger than the preset rate, the output end is forbidden to output signals. In a specific implementation, disabling the output terminal from outputting the signal may be implemented by disabling an output pin. The preset rate is set according to practical situations, and can be set to be 100V/s for example.
Wherein, the undervoltage protection threshold voltage Vuvlo is less than the overvoltage recovery threshold voltage Vovp _recovery, and the overvoltage recovery threshold voltage Vovp _recovery is less than the overvoltage protection threshold voltage Vovp. The overvoltage recovery threshold voltage Vovp _recovery may be set according to the actual situation.
In this embodiment, if the falling rate of the voltage at the input end is greater than the preset rate, it is indicated that the voltage at the input end is being removed, i.e. the voltage at the input end is continuously powered down, for example, the power is turned off, and at this time, by prohibiting the output signal from the output end, the output end can be prevented from generating a short pulse which is unfavorable for the electrical system, so that the reliability of the overvoltage protection device can be improved, and the reliability and the service life of the electrical system in which the overvoltage protection device is located can also be improved.
The first switch in this embodiment may be a switching device such as a MOS transistor or a triode, or may be a switching chip. If the first switch is turned on, the path between the input end and the output end is turned on, the output end has voltage output, and the voltage Vout at the output end is specifically the voltage Vin at the input end minus the internal voltage drop of the first switch. If the first switch is turned off, the path between the input end and the output end is disconnected, and no voltage is output from the output end, i.e. the voltage Vout of the output end is about 0V.
The control circuit may control the first switch to be turned on by outputting a high level signal to the first switch, and control the first switch to be turned off by outputting a low level signal to the first switch. The control circuit can also control the first switch to be turned on by outputting a low-level signal to the first switch, and control the first switch to be turned off by outputting a high-level signal to the first switch. In particular, the type of the first switch and the peripheral circuit of the first switch may be determined.
In order to further improve the reliability of the overvoltage protection device, in an alternative embodiment of step S4, if the rate of decrease of the voltage Vin at the input terminal monitored for a continuous preset number of times is greater than the preset rate, outputting a signal to the first switch is prohibited.
In an alternative embodiment, the following steps are further included after step S4: after a period of time the output is allowed to output a signal. In a specific implementation, the enabling of the output to output the signal may be implemented by enabling an output pin. In this embodiment, after the output terminal is allowed to output a signal, if the voltage of the input terminal rises to be higher than the undervoltage protection threshold voltage and lower than the overvoltage protection threshold voltage, the first switch is controlled to be turned on, and the output terminal normally outputs the signal.
In order to avoid fluctuations in the output voltage and to increase the immunity of the overvoltage protection device to spurious noise, in an alternative embodiment the first switch is controlled to be turned on or off for a time delay.
Example 3
The present embodiment provides an overvoltage protection device, including a memory, a processor, and a computer program stored on the memory and executable on the processor, the processor implementing the control method as described in embodiment 2 when executing the computer program.
In this embodiment, if the falling rate of the voltage at the input end is greater than the preset rate, it is indicated that the voltage at the input end is being removed, i.e. the voltage at the input end is continuously powered down, for example, the power is turned off, and at this time, by prohibiting the output signal at the output end, the output end can be prevented from generating a short pulse which is unfavorable for the electrical system, so that the reliability of the overvoltage protection device can be improved, and the reliability and the service life of the electrical system in which the overvoltage protection device is located can also be improved.
Example 4
The present embodiment provides an electronic device including the overvoltage protection device described in embodiment 1 or 3.
In this embodiment, if the falling rate of the voltage at the input end is greater than the preset rate, it is indicated that the voltage at the input end is being removed, i.e. the voltage at the input end is continuously powered down, for example, the power is turned off, and at this time, by prohibiting the output signal at the output end, the output end can avoid the occurrence of short pulses which are unfavorable for the electrical system, so that the reliability of the overvoltage protection device can be improved, and the reliability and the service life of the electronic device in which the overvoltage protection device is located can also be improved.
Example 5
This embodiment provides a chip comprising the overvoltage protection device of embodiment 1 or 3.
In this embodiment, if the falling rate of the voltage at the input end is greater than the preset rate, it is indicated that the voltage at the input end is being removed, i.e. the voltage at the input end is continuously powered down, for example, the power is turned off, and at this time, by prohibiting the output signal at the output end, the output end can be prevented from generating a short pulse which is unfavorable for the electrical system, so that the reliability of the overvoltage protection device can be improved, and the reliability and the service life of the chip where the overvoltage protection device is located can also be improved.
While specific embodiments of the invention have been described above, it will be appreciated by those skilled in the art that this is by way of example only, and the scope of the invention is defined by the appended claims. Various changes and modifications to these embodiments may be made by those skilled in the art without departing from the principles and spirit of the invention, but such changes and modifications fall within the scope of the invention.
Claims (10)
1. The overvoltage protection device is characterized by comprising an acquisition circuit, a monitoring circuit, a control circuit and a first switch connected in series between an input end and an output end;
The acquisition circuit is used for acquiring the voltage of the input end, the overvoltage protection threshold voltage and the undervoltage protection threshold voltage;
the monitoring circuit is used for monitoring the falling rate of the voltage of the input end and outputting a first level signal under the condition that the falling rate is larger than a preset rate;
The control circuit is used for controlling the first switch to be turned on when the voltage of the input end rises to be higher than the undervoltage protection threshold voltage and lower than the overvoltage protection threshold voltage, and controlling the first switch to be turned off when the voltage of the input end rises to be higher than the overvoltage protection threshold voltage; and
Controlling the first switch to be turned on when the voltage of the input end is reduced to be lower than an overvoltage recovery threshold voltage and higher than the undervoltage protection threshold voltage, and controlling the first switch to be turned off when the voltage of the input end is reduced to be lower than the undervoltage protection threshold voltage; and
Disabling the output from outputting a signal in response to the first level signal;
The under-voltage protection threshold voltage is smaller than the over-voltage recovery threshold voltage, and the over-voltage recovery threshold voltage is smaller than the over-voltage protection threshold voltage.
2. The overvoltage protection device according to claim 1, wherein said monitoring circuit is specifically configured to output said first level signal if said rate of decrease monitored for a predetermined number of consecutive times is greater than a predetermined rate.
3. The overvoltage protection device of claim 2, wherein the monitoring circuit includes a second switch, a third switch, a current source, a capacitor, and a comparator;
One end of the second switch is used for receiving the voltage of the input end, and the other end of the second switch is connected with one end of the capacitor and one end of the third switch respectively; the other end of the capacitor is grounded; the other end of the third switch is connected with the current source, and the control end of the second switch and the control end of the third switch are both connected with the control circuit; wherein the second switch and the third switch are not turned on at the same time;
One end of the comparator is connected with one end of the capacitor, the other end of the comparator is used for receiving the voltage of the input end, and the output end of the comparator is connected with the control circuit and is used for outputting the first level signal under the condition that the voltage of the input end is smaller than the voltage of one end of the capacitor;
And the voltage of the current source and the capacitance value of the capacitor are determined according to the preset speed.
4. The overvoltage protection device of claim 3, wherein the monitoring circuit further comprises a fourth switch, one end of the comparator is connected to one end of the capacitor through the fourth switch, and a control end of the fourth switch is connected to the control circuit; wherein the fourth switch and the second switch are not turned on at the same time.
5. The overvoltage protection device of claim 1 wherein said control circuit is further configured to begin timing responsive to said first level signal and to stop timing after a period of time;
The control circuit is specifically configured to allow the output terminal to output a signal after stopping the timing.
6. The overvoltage protection device according to any one of claims 1-5, wherein the control circuit is specifically configured to control the first switch to be turned on or off for a time delay.
7. A method of controlling an overvoltage protection device, comprising the steps of:
Acquiring the voltage of an input end, an overvoltage protection threshold voltage and an undervoltage protection threshold voltage;
If the voltage of the input end rises to be higher than the undervoltage protection threshold voltage and lower than the overvoltage protection threshold voltage, controlling a first switch connected in series between the input end and the output end to be turned on, and if the voltage of the input end rises to be higher than the overvoltage protection threshold voltage, controlling the first switch to be turned off;
Controlling the first switch to be turned on if the voltage of the input end is reduced to be lower than the overvoltage recovery threshold voltage and higher than the undervoltage protection threshold voltage, and controlling the first switch to be turned off if the voltage of the input end is reduced to be lower than the undervoltage protection threshold voltage;
If the falling rate of the voltage of the input end is larger than the preset rate, the output end is forbidden to output signals;
The under-voltage protection threshold voltage is smaller than the over-voltage recovery threshold voltage, and the over-voltage recovery threshold voltage is smaller than the over-voltage protection threshold voltage.
8. An overvoltage protection device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, characterized in that the processor implements the control method according to claim 7 when executing the computer program.
9. An electronic device comprising an overvoltage protection device according to any one of claims 1-6, 8.
10. A chip comprising an overvoltage protection device according to any one of claims 1-6, 8.
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| CN202210899966.8A CN115173365B (en) | 2022-07-28 | 2022-07-28 | Control method of overvoltage protection device and overvoltage protection device |
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| CN202210899966.8A CN115173365B (en) | 2022-07-28 | 2022-07-28 | Control method of overvoltage protection device and overvoltage protection device |
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| CN115173365B true CN115173365B (en) | 2024-05-03 |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA1235742A (en) * | 1982-07-28 | 1988-04-26 | Neil A. Kammiller | Overvoltage protection circuit for a power supply |
| US5285344A (en) * | 1990-12-10 | 1994-02-08 | Sgs-Thomson Microelectronics Gmbh | Overvoltage protection device |
| CN102097778A (en) * | 2011-02-11 | 2011-06-15 | 上海诺雅克电气有限公司 | Energy-saving undervoltage/overvoltage protective device |
| CN103036196A (en) * | 2012-12-03 | 2013-04-10 | 华为技术有限公司 | Device for overvoltage protection and method thereof |
| CN104682341A (en) * | 2013-11-28 | 2015-06-03 | 海洋王（东莞）照明科技有限公司 | Over-voltage/low-voltage protective circuit |
-
2022
- 2022-07-28 CN CN202210899966.8A patent/CN115173365B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA1235742A (en) * | 1982-07-28 | 1988-04-26 | Neil A. Kammiller | Overvoltage protection circuit for a power supply |
| US5285344A (en) * | 1990-12-10 | 1994-02-08 | Sgs-Thomson Microelectronics Gmbh | Overvoltage protection device |
| CN102097778A (en) * | 2011-02-11 | 2011-06-15 | 上海诺雅克电气有限公司 | Energy-saving undervoltage/overvoltage protective device |
| CN103036196A (en) * | 2012-12-03 | 2013-04-10 | 华为技术有限公司 | Device for overvoltage protection and method thereof |
| CN104682341A (en) * | 2013-11-28 | 2015-06-03 | 海洋王（东莞）照明科技有限公司 | Over-voltage/low-voltage protective circuit |
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| CN115173365A (en) | 2022-10-11 |
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