CN112649724A - Power failure detection circuit and method and MCU chip - Google Patents
Power failure detection circuit and method and MCU chip Download PDFInfo
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- CN112649724A CN112649724A CN201910965290.6A CN201910965290A CN112649724A CN 112649724 A CN112649724 A CN 112649724A CN 201910965290 A CN201910965290 A CN 201910965290A CN 112649724 A CN112649724 A CN 112649724A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/28—Testing of electronic circuits, e.g. by signal tracer
- G01R31/317—Testing of digital circuits
- G01R31/31721—Power aspects, e.g. power supplies for test circuits, power saving during test
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/28—Testing of electronic circuits, e.g. by signal tracer
- G01R31/317—Testing of digital circuits
- G01R31/31703—Comparison aspects, e.g. signature analysis, comparators
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/28—Testing of electronic circuits, e.g. by signal tracer
- G01R31/317—Testing of digital circuits
- G01R31/31725—Timing aspects, e.g. clock distribution, skew, propagation delay
- G01R31/31726—Synchronization, e.g. of test, clock or strobe signals; Signals in different clock domains; Generation of Vernier signals; Comparison and adjustment of the signals
Abstract
The application provides a power failure detection circuit, a power failure detection method and an MCU chip, and belongs to the technical field of terminals. The power failure detection circuit comprises an information acquisition unit and a comparator, wherein a first input pin of the comparator is connected with an output pin of an external power supply of a target chip, and a second input pin of the comparator is connected with an output pin of a standby battery of the target chip and is used for comparing the voltages of the external power supply and the standby battery; the information acquisition unit is respectively connected with an output pin of the comparator and the MCU of the target chip and is used for acquiring a comparison result of the comparator, determining the power supply state of the external power supply according to the comparison result and outputting a switching signal of a working mode to the MCU according to the power supply state. By adopting the method and the device, the power consumption of the MCU can be reduced.
Description
Technical Field
The application relates to the technical field of terminals, in particular to a power failure detection circuit and method and an MCU chip.
Background
With the development of electronic technology, more and more devices are pursuing low power consumption design of chips to save the energy consumption of the devices.
In the related art, an electronic device may generally supply power to an MCU (micro controller Unit) chip in two ways, one is supplied by a stable external power source, and the other is supplied by a battery of the device. Correspondingly, the MCU chip can support a normal mode and a low power consumption mode, when a stable power supply supplies power to the MCU chip, the MCU chip works in the normal mode, and works in the low power consumption mode under the condition of battery power supply. In order to realize the switching of the working mode, the MCU in the MCU chip needs to continuously detect whether the power supply of the external power supply is normal or not, and switches to the low power consumption mode when detecting the power failure of the external power supply.
However, the MCU continuously detects whether the external power source is normally powered or not, and consumes a small amount of power.
Disclosure of Invention
An object of the embodiments of the present application is to provide a power failure detection circuit, a power failure detection method, and an MCU chip, so as to solve the problem that MCU power consumption is high due to MCU continuous detection of whether an external power supply is normally powered. The specific technical scheme is as follows:
in a first aspect, a power failure detection circuit is provided, which includes an information acquisition unit and a comparator, wherein:
a first input pin of the comparator is connected with an output pin of an external power supply of a target chip, and a second input pin of the comparator is connected with an output pin of a standby battery of the target chip and used for comparing the voltages of the external power supply and the standby battery;
the information acquisition unit is respectively connected with an output pin of the comparator and the MCU of the target chip and is used for acquiring a comparison result of the comparator, determining the power supply state of the external power supply according to the comparison result and outputting a switching signal of a working mode to the MCU according to the power supply state.
Optionally, the MCU is further configured to output a low-frequency clock signal;
the information acquisition unit is further used for acquiring the comparison result of the comparator according to the clock period of the low-frequency clock signal.
Optionally, the power failure detection circuit further includes a power supply controller, and the power supply controller is connected to the external power supply, the information acquisition unit, and the comparator respectively;
the information acquisition unit is also used for controlling the comparator to be powered on or powered off through the power supply controller.
Optionally, the power supply controller is a metal oxide semiconductor MOS transistor.
Optionally, a positive input pin of the comparator is connected to the external power supply, and a negative input pin of the comparator is connected to the backup battery.
In a second aspect, a power down detection method is provided, which is applied to the power down detection circuit according to any one of the first aspect, and the method includes:
the comparator compares the voltages of the external power supply and the standby battery to obtain a comparison result;
the information acquisition unit acquires the comparison result of the comparator, determines the power supply state of the external power supply according to the comparison result, and outputs a switching signal of a working mode to the MCU according to the power supply state.
Optionally, the acquiring the comparison result of the comparator, determining the power supply state of the external power supply according to the comparison result, and outputting a switching signal of a working mode to the MCU according to the power supply state includes:
if the comparison result is a low level, the information acquisition unit determines that the power supply state of the external power supply is a power-down state, and outputs a first switching signal, wherein the first switching signal is used for controlling the MCU to switch to a low power consumption mode;
and if the comparison result is a high level, the information acquisition unit determines that the power supply state of the external power supply is a normal power supply state, and outputs a second switching signal, wherein the second switching signal is used for controlling the MCU to switch to a normal working mode.
Optionally, before the comparator compares the voltages of the external power supply and the backup battery, the comparator further includes:
when the information acquisition unit receives a low-frequency clock signal sent by the MCU, starting to count the low-frequency clock signal;
and the information acquisition unit controls the power supply controller to supply power to the comparator in a first clock period after the count value reaches a preset threshold value.
Optionally, the acquiring the comparison result of the comparator by the information acquiring unit includes:
and the information acquisition unit acquires the comparison result of the comparator in a second clock period after the count value reaches a preset threshold value.
Optionally, after the information acquisition unit acquires the comparison result of the comparator, the method further includes:
and the information acquisition unit controls the power supply controller to power off the comparator.
In a third aspect, an MCU chip is provided, where the MCU chip includes the power down detection circuit according to any one of the first aspect.
The embodiment of the application has the following beneficial effects:
the embodiment of the application provides a power failure detection circuit, a power failure detection method and an MCU chip, wherein the power failure detection circuit comprises an information acquisition unit and a comparator. A first input pin of the comparator is connected with an output pin of an external power supply of the target chip, and a second input pin of the comparator is connected with an output pin of a standby battery of the target chip and used for comparing the voltages of the external power supply and the standby battery; the information acquisition unit is respectively connected with an output pin of the comparator and the MCU of the target chip and is used for acquiring a comparison result of the comparator, determining the power supply state of the external power supply according to the comparison result and outputting a switching signal of a working mode to the MCU according to the power supply state. In this scheme, realize external power source's power down detection through comparator and information acquisition unit, need not MCU and continuously detect, reduced MCU's consumption.
Of course, not all advantages described above need to be achieved at the same time in the practice of any one product or method of the present application.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.
Fig. 1 is a schematic diagram of a power supply system of an MCU chip provided in an embodiment of the present application;
fig. 2 is a circuit diagram of a power down detection circuit according to an embodiment of the present application;
fig. 3 is a flowchart of a power failure detection method according to an embodiment of the present application;
fig. 4 is a flowchart of another power failure detection method according to an embodiment of the present application.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The embodiment of the application provides a power failure detection circuit, which can be used for detecting whether an external power supply of an MCU chip supplies power normally. Currently, electronic devices can generally supply power to MCU chips in two ways, one is supplied by a stable external power source, and the other is supplied by the battery of the device. For convenience of explanation, the embodiment of the present application first provides a schematic diagram of a power supply system of an MCU chip. As shown in fig. 1, the power supply system includes an external power supply (VCC) and a battery backup (VBB), and the external power supply can provide a regulated power supply through a voltage stabilizer, and can provide sufficient and stable power for the MCU chip: the backup battery can provide backup power for the MCU chip when the external power supply stops supplying power (such as power failure or external power supply failure). In an implementation manner, the MCU chip provided in the embodiment of the present application may be applied to electronic devices in application environments where there is a possibility of power failure, such as a household air conditioner, a household washing machine, and an intelligent electric cooker. If the commercial power is suddenly cut off, the electronic equipment starts the standby battery to supply power, and correspondingly, the MCU chip immediately switches from the normal mode to the low power consumption mode to work, so that the power consumption is reduced, and the service time of the standby battery is prolonged. Therefore, when the commercial power is recovered and the commercial power is switched back to the commercial power (the commercial power is supplied by a voltage stabilizer with voltage reduction, rectification, filtering and voltage stabilization), the data in the MCU chip is not lost, and the work can be continuously finished.
In fig. 1, a power supply pin of the backup battery is connected to a power supply input pin a1 of the MCU chip, and a power supply pin of the external power supply is connected to a power supply input pin a2 of the MCU chip. The power supply output end of the standby battery is provided with a diode D1, and the diode D1 can be used for protecting the standby battery from being charged. In addition, since the supply voltage of the external power supply is usually higher than the supply voltage of the backup battery, a diode D2 is also provided between the supply pin of the backup battery and the supply pin of the external power supply to save the power consumption of the backup battery when the external power supply supplies power. The MCU chip can be internally divided into a module A and a module B, wherein the module A is a part with larger power consumption and needs to be closed in a low power consumption mode, and the module B is a part which needs to keep working in the low power consumption mode. When the mains supply is available, the whole power consumption of the MCU is simultaneously operated by the voltage stabilizer power supply module A and the voltage stabilizer power supply module B, and when the standby battery supplies power, the power supply gate control associated with the module A is closed, so that the power consumption is saved.
As shown in fig. 2, the power failure detection circuit provided in the embodiment of the present application includes an information acquisition unit and a comparator. The first input pin of the comparator is connected with the output pin of the external power supply of the target chip, and the second input pin of the comparator is connected with the output pin of the standby battery of the target chip and used for comparing the voltages of the external power supply and the standby battery.
The information acquisition unit is respectively connected with an output pin of the comparator and the MCU of the target chip and is used for acquiring a comparison result of the comparator, determining the power supply state of the external power supply according to the comparison result and outputting a switching signal of a working mode to the MCU according to the power supply state.
Optionally, the MCU is further configured to output a low-frequency clock signal, and the information acquisition unit is further configured to acquire a comparison result of the comparator according to a clock period of the low-frequency clock signal.
Wherein, the low frequency clock signal may be a 32k low frequency clock signal.
Optionally, the power failure detection circuit further comprises a power supply controller, and the power supply controller is respectively connected with the external power supply, the information acquisition unit and the comparator;
and the information acquisition unit is also used for controlling the comparator to be powered on or powered off through the power supply controller.
Specifically, the power supply controller may be an MOS transistor, and referring to fig. 2, a first input end of the MOS transistor is connected to the information acquisition unit and configured to receive a control signal sent by the information acquisition unit, a second input end of the MOS transistor is connected to an external power supply, and an output end of the MOS transistor is connected to a power input point of the comparator so as to supply power to the comparator.
Optionally, a positive input pin of the comparator is connected to an external power supply, and a negative input pin of the comparator is connected to the backup battery.
Based on this connection, when VCC is normally powered, the output of the comparator is positive (i.e., a high-level electrical signal), and when VCC is not powered and VBB is powered, the output of the comparator is negative (i.e., a low-level electrical signal). Based on the characteristic, the information acquisition unit can judge whether the VCC is normally powered according to the comparison result output by the comparator, and the power failure detection of the VCC is realized. And, can detect when VCC falls the electricity, control MCU chip and enter the low-power consumption mode to can detect when VCC supplies power again, control MCU chip and enter normal mode.
Optionally, in another implementation, the negative input pin of the comparator may also be connected to an external power supply, and the positive input pin of the comparator is connected to the backup battery. The specific comparison process is opposite to the above, and the embodiment of the present application is not described in detail again.
As shown in fig. 3, an embodiment of the present application further provides a power failure detection method, which can be applied to the power failure detection circuit, and the method specifically includes the following steps.
In step 301, the comparator compares the voltages of the external power supply and the backup battery to obtain a comparison result.
In the embodiment of the application, because the first input pin of the comparator is connected with the output pin of the external power supply of the target chip, and the second input pin of the comparator is connected with the output pin of the standby battery of the target chip, the comparator can obtain the voltages of the external power supply and the standby battery, and then can compare the two voltages to obtain the comparison result.
Referring to fig. 2, a positive input pin of the comparator is connected to an external power source, and a negative input pin of the comparator is connected to a backup battery. Based on the connection mode, when VCC is normally supplied, VCC > VBB is positive, and the comparator outputs a high-level electric signal. When VCC stops supplying power and VBB supplies power, VCC < VBB is negative, the comparison result of the comparator is negative, and the comparator outputs an electric signal with low level.
And 302, acquiring a comparison result of the comparator by the information acquisition unit, determining a power supply state of the external power supply according to the comparison result, and outputting a switching signal of a working mode to the MCU according to the power supply state.
In the embodiment of the application, the information acquisition unit can judge whether the VCC is normally powered according to the comparison result output by the comparator, and the power failure detection of the VCC is realized. And, can detect when VCC falls the electricity, control MCU chip and enter the low-power consumption mode to can detect when VCC supplies power again, control MCU chip and enter normal mode.
Optionally, based on the power failure detection current shown in fig. 2, the information acquisition unit acquires a comparison result of the comparator, determines a power supply state of the external power supply according to the comparison result, and outputs a specific processing procedure of a switching signal of the working mode to the MCU according to the power supply state, where the specific processing procedure is as follows: if the comparison result is low level, the information acquisition unit determines that the power supply state of the external power supply is a power-down state, and outputs a first switching signal, wherein the first switching signal is used for controlling the MCU to switch to a low power consumption mode; and if the comparison result is high level, the information acquisition unit determines that the power supply state of the external power supply is a normal power supply state, and outputs a second switching signal, wherein the second switching signal is used for controlling the MCU to switch to a normal working mode.
In the embodiment of the application, if the comparison result is a low level, it indicates that VCC > VBB, the information acquisition unit may determine that the power supply state of the external power supply is a power-down state, and then output a first switching signal, where the first switching signal is used to control the MCU to switch to the low power consumption mode. After receiving the first switching signal, the MCU may turn off the power gate associated with module a to turn off all components in module a, and only keep module B in working state, thereby saving power consumption.
If the comparison result is high level, it indicates that VCC is less than VBB, the information acquisition unit determines that the power supply state of the external power supply is normal power supply state, and outputs a second switching signal, and the second switching signal is used for controlling the MCU to switch to the normal working mode. After receiving the first switching signal, the MCU may turn off the power gate associated with module a to turn off all components in module a, and only keep module B in working state, thereby saving power consumption. After the information acquisition unit outputs the switching signal, the MCU can judge whether the current state needs to be switched, if the current state needs to be switched, the switching is carried out according to the switching, and if the current state does not need to be switched, the signal can be ignored. For example, if the MCU is currently in a normal operating state, the MCU is switched to the low power mode after receiving the first switching signal, and if the MCU is currently in the low power mode, the MCU does not need to be switched. The situation that the MCU receives the second switching signal is similar and will not be described again.
Optionally, when the information acquisition unit receives a low-frequency clock signal sent by the MCU, the low-frequency clock signal is counted, and in a first clock period after the count value reaches a preset threshold, the power supply controller is controlled to supply power to the comparator, so that the comparator operates, i.e., the voltage of the external power supply is compared with the voltage of the backup battery.
In this application embodiment, MCU the low frequency clock signal of sending that can last, MCU work is in the low frequency state promptly, and power consumption is few. Wherein, the low frequency clock signal may be a 32k low frequency clock signal. The information acquisition unit can be provided with a time sequence control module and a timer. The timing control circuit can control the power supply controller to supply power to the comparator. Specifically, after receiving the low-frequency clock signal sent by the MCU, the timing control module may drive the timer to count by using the low-frequency clock signal, and when the counter is full (i.e., reaches a preset threshold), the timing control module may turn on the power supply controller in a clock cycle (i.e., a first clock cycle) of a next low-frequency clock signal, thereby supplying power to the comparator.
Optionally, the information acquisition unit may acquire the comparison result of the comparator in a second clock cycle after the count value reaches the preset threshold.
In the embodiment of the present application, the second clock period may be the same as or different from the first clock period. In one implementation, after the comparator is powered on in the first clock cycle, the information acquisition unit may sample data of the comparator in the next clock cycle (i.e., the second clock cycle). That is, the second clock cycle is the next clock cycle of the first clock cycle. Therefore, after the comparator is powered for a certain time, the output result of the comparator is collected, the instable power-on time of the comparator can be avoided, the effectiveness of the collected output result is improved, and the judgment accuracy of the information collection unit is improved.
Optionally, after the information acquisition unit acquires the comparison result of the comparator, the power supply controller may be further controlled to power off the comparator, and after a preset time interval is reached, the power supply controller is controlled again to supply power to the comparator.
In this embodiment, the third clock cycle may be a clock cycle after the second clock cycle. After the power of the comparator is cut off, the information acquisition unit can control the power supply controller to supply power to the comparator again after a preset time interval is reached so as to acquire the comparison result of the comparator again, and therefore whether the external power supply is powered off or not is judged periodically. For example, the information collecting unit supplies power to the comparator in T1 through the power supply controller, then collects the comparison result of the comparator in T2, and then the power supply controller stops supplying power to the comparator. And when the preset time interval is reached, the power supply controller is controlled again to supply power to the comparator so as to detect the power supply condition of the external power supply again.
The embodiment of the present application further provides an example of a power failure detection method, as shown in fig. 4, specifically including the following steps.
Step 401, the information acquisition unit receives a low frequency clock signal sent by the MCU.
Step 402, the information acquisition unit drives a timer to count by using a low-frequency clock signal.
And 403, when the count value reaches a preset threshold value, the information acquisition unit turns on the MOS transistor to supply power to the comparator in the first clock cycle.
In step 404, the comparator compares the voltages of the external power source and the backup battery to obtain a comparison result.
In step 405, the information collecting unit samples the comparison result of the comparator in a second clock cycle after the first clock cycle.
In step 406, the information collecting unit determines whether the comparison result is a low level.
If the comparison result is low level, executing steps 407-408;
if the comparison result is high level, then steps 409-410 are executed.
Step 407, the information collecting unit outputs a first switching signal
Step 408, the MCU switches to a low power consumption mode
In step 409, the information acquisition unit outputs a second switching signal.
Step 410, the MCU switches to the normal operation mode.
In the embodiment of the application, the power failure detection circuit comprises an information acquisition unit and a comparator. A first input pin of the comparator is connected with an output pin of an external power supply of the target chip, and a second input pin of the comparator is connected with an output pin of a standby battery of the target chip and used for comparing the voltages of the external power supply and the standby battery; the information acquisition unit is respectively connected with an output pin of the comparator and the MCU of the target chip and is used for acquiring a comparison result of the comparator, determining the power supply state of the external power supply according to the comparison result and outputting a switching signal of a working mode to the MCU according to the power supply state. In this scheme, realize external power source's power down detection through comparator and information acquisition unit, need not MCU and continuously detect, reduced MCU's consumption.
Based on the same technical concept, the embodiment of the invention also provides an MCU chip, wherein the MUC chip can comprise the power failure detection circuit and the MCU, and the MCU chip can be powered by an external power supply or a standby battery. The power failure detection circuit comprises an information acquisition unit and a comparator. A first input pin of the comparator is connected with an output pin of an external power supply of the target chip, and a second input pin of the comparator is connected with an output pin of a standby battery of the target chip and used for comparing the voltages of the external power supply and the standby battery; the information acquisition unit is respectively connected with an output pin of the comparator and the MCU of the target chip and is used for acquiring a comparison result of the comparator, determining the power supply state of the external power supply according to the comparison result and outputting a switching signal of a working mode to the MCU according to the power supply state. In this scheme, realize external power source's power down detection through comparator and information acquisition unit, need not MCU and continuously detect, reduced MCU's consumption.
It is noted that, in this document, relational terms such as "first" and "second," and the like, may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
The above description is merely exemplary of the present application and is presented to enable those skilled in the art to understand and practice the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (11)
1. The utility model provides a power down detection circuit which characterized in that, power down detection circuit includes information acquisition unit and comparator, wherein:
a first input pin of the comparator is connected with an output pin of an external power supply of a target chip, and a second input pin of the comparator is connected with an output pin of a standby battery of the target chip and used for comparing the voltages of the external power supply and the standby battery;
the information acquisition unit is respectively connected with an output pin of the comparator and the MCU of the target chip and is used for acquiring a comparison result of the comparator, determining the power supply state of the external power supply according to the comparison result and outputting a switching signal of a working mode to the MCU according to the power supply state.
2. The power down detection circuit of claim 1, wherein the MCU is further configured to output a low frequency clock signal;
the information acquisition unit is further used for acquiring the comparison result of the comparator according to the clock period of the low-frequency clock signal.
3. The power-down detection circuit according to claim 1, further comprising a power supply controller, the power supply controller being connected to the external power supply, the information acquisition unit, and the comparator, respectively;
the information acquisition unit is also used for controlling the comparator to be powered on or powered off through the power supply controller.
4. The power down detection circuit of claim 3, wherein the power supply controller is a Metal Oxide Semiconductor (MOS) transistor.
5. The power down detection circuit of claim 1, wherein a positive input pin of the comparator is connected to the external power source, and a negative input pin of the comparator is connected to the backup battery.
6. A power down detection method applied to the power down detection circuit according to any one of claims 1 to 5, the method comprising:
the comparator compares the voltages of the external power supply and the standby battery to obtain a comparison result;
the information acquisition unit acquires the comparison result of the comparator, determines the power supply state of the external power supply according to the comparison result, and outputs a switching signal of a working mode to the MCU according to the power supply state.
7. The method according to claim 6, wherein the collecting unit collects a comparison result of the comparator, determines a power supply state of the external power supply according to the comparison result, and outputs a switching signal of an operating mode to the MCU according to the power supply state, and the method comprises:
if the comparison result is a low level, the information acquisition unit determines that the power supply state of the external power supply is a power-down state, and outputs a first switching signal, wherein the first switching signal is used for controlling the MCU to switch to a low power consumption mode;
and if the comparison result is a high level, the information acquisition unit determines that the power supply state of the external power supply is a normal power supply state, and outputs a second switching signal, wherein the second switching signal is used for controlling the MCU to switch to a normal working mode.
8. The method of claim 6, wherein before the comparator compares the voltages of the external power source and the backup battery, further comprising:
when the information acquisition unit receives a low-frequency clock signal sent by the MCU, starting to count the low-frequency clock signal;
and the information acquisition unit controls the power supply controller to supply power to the comparator in a first clock period after the count value reaches a preset threshold value.
9. The method of claim 8, wherein the information collecting unit collects the comparison result of the comparator, and comprises:
and the information acquisition unit acquires the comparison result of the comparator in a second clock period after the count value reaches a preset threshold value.
10. The method of claim 6, wherein after the information collecting unit collects the comparison result of the comparator, the method further comprises:
and the information acquisition unit controls the power supply controller to power off the comparator.
11. An MCU chip, characterized in that the MCU chip comprises the power down detection circuit of any of claims 1 to 5.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN114036895A (en) * | 2021-11-08 | 2022-02-11 | 南方电网数字电网研究院有限公司 | Self-adaptive voltage regulation SoC system and control method |
| CN114397957A (en) * | 2022-01-15 | 2022-04-26 | 上海列拓科技有限公司 | Low-power-consumption power management circuit for MCU chip, and MCU chip |
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