Arbitrary key awakening and low-dropout power supply switching circuit based on power failure monitoring

Abstract

The utility model is suitable for the technical field of intelligent distribution networks, and relates to a power failure monitoring-based arbitrary key wake-up and low-dropout power supply switching circuit, which comprises a power failure monitoring circuit, an arbitrary key wake-up circuit and a low-dropout standby power supply booster circuit, the power failure monitoring circuit comprises a voltage stabilizing diode V1, a triode V217 and a triode V218; the arbitrary key wake-up circuit comprises a triode V212 and a triode V216, a base electrode of the triode V216 is connected with the power failure monitoring circuit, and a collector electrode of the triode V216 is connected with a base electrode of the triode V212; and the low-dropout standby power supply booster circuit comprises a resistor R431, a resistor R432, a triode V197 and a triode V198. According to the utility model, the problems in the prior art that the awakening cannot be realized by any key in the awakening process, the conditions of repeated restart and awakening failure exist, and the high-low temperature and normal temperature are inconsistent due to the difference of device parameters are solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of intelligent distribution networks, and in particular relates to an arbitrary key-press wake-up and low-voltage difference power supply switching circuit based on power-off monitoring. Background Art

[0002] At present, power terminal equipment power failure monitoring, backup power supply and button wake-up functions have been generally built into the equipment. The types of power terminal backup power supply include supercapacitors and backup batteries. Supercapacitors are generally put into use immediately after the external power supply fails to meet the backup time and reporting requirements. Backup batteries are also often put into use immediately after the terminal loses power, and the terminal software actively shuts down the backup power after a period of time, or exists as a supplementary function of the supercapacitor to extend the backup time. Another important function of the backup battery is to meet the terminal's button wake-up after the external power fails.

[0003] The key-press wake-up circuit commonly used in terminals currently has a relatively complex logic circuit structure as a whole, and can only realize specified keys to wake up the terminal, and cannot realize arbitrary key wake-up. The power-off detection circuit needs to meet the minimum operating threshold value of the specific chip to work reliably. When the key-press wake-up circuit is applied, there will inevitably be a situation where it is lower than the minimum operating threshold. At this time, the corresponding power-off signal is abnormally pulled high. Therefore, when the key is pressed to wake up, the system will repeatedly restart or fail to wake up. In addition, in actual application, the power-off detection circuit needs to be used with specific diodes and voltage divider resistors to ensure the reliable operation of the subsequent transistors. Otherwise, there will be a situation where it is always on or always off. However, due to differences in device parameters, there are inconsistent performances at high and low temperatures and normal temperatures. The patent application with publication number CN211653439U provides a key wake-up circuit and electronic equipment, the key circuit includes a key, the key circuit is used to output a first level signal when the battery assembly is in a low-power state and the key is pressed; the wake-up circuit is electrically connected to the battery assembly and the key circuit, respectively, for waking up according to the first level signal and converting the output voltage of the battery assembly into a power supply voltage; the control circuit is electrically connected to the battery assembly, the key circuit and the wake-up circuit, respectively, for working according to the power supply voltage, detecting the key action of the key, and executing a preset operation according to the key action. The wake-up circuit in this scheme only has one specific key for wake-up, and cannot wake up by any key. It may also cause repeated restarts or wake-up failures, and has the same disadvantages as the prior art.

[0004] Therefore, it is urgent to solve the problems that the existing technology cannot wake up by pressing any button during the wake-up process, there are repeated restarts and wake-up failures, and the performance is inconsistent between high and low temperatures and normal temperatures due to differences in device parameters. Utility Model Content

[0005] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide an arbitrary key wake-up and low-voltage difference power switching circuit based on power-off monitoring, so as to solve the problems that the existing technology cannot achieve arbitrary key wake-up during the wake-up process, there are repeated restarts and wake-up failures, and the problems of inconsistent performance at high and low temperatures and normal temperatures due to differences in device parameters.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] The utility model provides a circuit for waking up with any key and switching low-voltage power supply based on power-off monitoring, comprising:

[0008] Power-off monitoring circuit, any-key wake-up circuit and low-voltage-drop backup power boost circuit;

[0009] The power-off monitoring circuit includes a voltage-stabilizing diode V1, a transistor V217, and a transistor V218. The cathode of the voltage-stabilizing diode V1 is connected to the external input power supply V12P0, the anode of the voltage-stabilizing diode V1 is connected to the base of the transistor V218, and the collector of the transistor V218 is connected to the base of the transistor V217. The arbitrary key wake-up circuit includes a transistor V212 and a transistor V216. The base of the transistor V216 is connected to the power-off monitoring circuit. The transistor V2 16 is connected to the base of the transistor V212; the low voltage difference standby power supply boost circuit includes a resistor R431, a resistor R432, a transistor V197 and a transistor V198, one end of the resistor R431 is connected to the third pin of the transistor V197, and the other end is connected to the base of the transistor V198, one end of the resistor R432 is connected to the first pin of the transistor V197 and the collector of the transistor V198 respectively, and the other end is connected to the external power supply V12P0_SYS.

[0010] Furthermore, the power-off monitoring circuit also includes a resistor R885, a resistor R888, a resistor R889, a capacitor C96 and a capacitor C411. One end of the resistor R885 is connected to the external input power supply V12P0, and the other end is connected to the negative electrode of the voltage-stabilizing diode V1 and one end of the capacitor C96, respectively. The other end of the capacitor C96 is grounded. One end of the resistor R889 is connected to the base of the transistor V217 and the collector of the transistor V218, respectively, and the other end is connected to one end of the resistor R888. The other end of the resistor R888 is connected to the collector of the transistor V217 and the arbitrary key wake-up circuit, respectively. One end of the capacitor C411 is connected to the arbitrary key wake-up circuit, and the other end is connected to the emitter of the transistor V217.

[0011] Furthermore, the arbitrary key wake-up circuit further includes a diode V213, a diode V214, a resistor R671, a resistor R672, a resistor R675 and a transistor V209, the anode of the diode V213 is connected to the control end of the key circuit, the anode of the diode V214 is connected to the CPU output end, the cathode of the diode V213 and the cathode of the diode V214 are respectively connected to one end of the resistor R672, and the other end of the resistor R672 is connected to the transistor V The collector of transistor 216 and the base of transistor V212 are respectively connected, the collector of transistor V212 is respectively connected to one end of the resistor R671 and the first pin of transistor V209, the base of transistor V216 is connected to one end of the resistor R675, the other end of the resistor R675 is connected to the power-off monitoring circuit, the second pin of transistor V209 is connected to the other end of the resistor R671, and the third pin of transistor V2019 is connected to the backup battery.

[0012] Furthermore, the key circuit includes a switch K1, a switch K2, a switch K3, a switch K4, a switch K5, a switch K6, a diode V53, a diode V220, a diode V221, a diode V223, a diode V225, and a diode V228. The switches K1, K2, K3, K4, K5, and K6 are connected in parallel with each other. The switch K1 is connected to the cathode of the diode V53, the switch K2 is connected to the cathode of the diode V220, the switch K3 is connected to the cathode of the diode V221, the switch K4 is connected to the cathode of the diode V223, the switch K5 is connected to the cathode of the diode V225, and the switch K6 is connected to the cathode of the diode V228. The anodes of the diodes V53, V220, V221, V223, V225, and V228 are combined to output a control signal.

[0013] Furthermore, the low voltage difference backup power supply boost circuit also includes a chip D13, a resistor R150 and a resistor R160, the 11th pin of the chip D13 is connected to the backup battery, one end of the resistor R150 is connected to the 6th pin of the chip D13, and the other end is connected to one end of the resistor R160, and the other end of the resistor R160 is connected to the 8th pin of the chip D13.

[0014] Compared with the prior art, the arbitrary key wake-up and low-voltage difference power supply switching circuit based on power-off monitoring provided by the present invention has at least the following beneficial effects:

[0015] The circuit of the prior art cannot wake up by pressing any button during the wake-up process, and there are repeated restarts and wake-up failures, as well as inconsistent performance at high and low temperatures and normal temperatures due to differences in device parameters. The utility model has a simple structure and powerful functions. The power-off monitoring circuit is based on the fixed conduction value of the voltage-stabilizing diode and the transistor, and discrete components are used at the same time. It is not limited by the minimum operating voltage threshold value, and the power-off monitoring circuit works stably and reliably. The logic circuit for waking up by pressing any button realizes the design of waking up the terminal after pressing multiple buttons or any button of the terminal, and they are not affected by each other. The wake-up circuit design based on the power-off monitoring signal and the CPU control logic avoids abnormal losses caused by false triggering of the backup battery power supply when there is normal power, and the circuit is simple, reliable and efficient. In the low-voltage difference backup power boost circuit, the backup battery passes through the boost chip and the low-voltage difference power switching circuit, which can meet the low-voltage difference ripple requirements of the terminal device for the interface circuit, and avoid the voltage difference uncertainty and large ripple caused by ordinary diodes. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the solution of the present invention, a brief introduction will be given below to the figures required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 A block diagram of a circuit for waking up with any key and switching low-voltage-dropout power supply based on power-off monitoring provided by an embodiment of the present invention;

[0018] Figure 2 A power-off monitoring circuit diagram of an arbitrary key wake-up and low-voltage difference power switching circuit based on power-off monitoring provided by an embodiment of the utility model;

[0019] Figure 3 A key logic circuit diagram of a key wake-up circuit based on power-off monitoring and a low-voltage difference power switching circuit provided by an embodiment of the utility model;

[0020] Figure 4 A key circuit diagram of a key-press wake-up circuit based on power-off monitoring and a low-voltage difference power switching circuit provided by an embodiment of the utility model;

[0021] Figure 5 Another key logic circuit diagram of an arbitrary key wake-up circuit based on power-off monitoring and a low-voltage difference power switching circuit provided by an embodiment of the utility model;

[0022] Figure 6The present invention provides a low-voltage difference backup power boost circuit diagram of an arbitrary key wake-up circuit based on power-off monitoring and a low-voltage difference power switching circuit. DETAILED DESCRIPTION

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art to which this invention pertains; the terms used in this specification are for the purpose of describing specific embodiments only and are not intended to limit this invention; for example, terms such as “length,” “width,” “up,” “down,” “left,” “right,” “front,” “back,” “vertical,” “horizontal,” “top,” “bottom,” “inside,” and “outside” indicate directions or positions based on those shown in the accompanying drawings, which are for ease of description only and are not to be construed as limiting this technical solution.

[0024] The terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions; the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish different objects rather than to describe a specific order. In the specification and claims of the present invention and the above-mentioned drawings, when an element is referred to as being "fixed on" or "mounted on" or "disposed on" or "connected to" another element, it may be directly or indirectly located on the other element. For example, when an element is referred to as being "connected to" another element, it may be directly or indirectly connected to the other element.

[0025] Furthermore, references to "embodiments" herein mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0026] The utility model provides a circuit for waking up with any key and switching low-voltage difference power supply based on power failure monitoring, which is applied to the process of realizing power failure monitoring, backup power supply and key wake-up functions of power terminal equipment. The circuit for waking up with any key and switching low-voltage difference power supply based on power failure monitoring includes:

[0027] Power-off monitoring circuit, any key wake-up circuit and low-voltage difference standby power boost circuit; the power-off monitoring circuit includes a voltage-stabilizing diode V1, a transistor V217 and a transistor V218, the cathode of the voltage-stabilizing diode V1 is connected to the external input power supply V12P0, the anode of the voltage-stabilizing diode V1 is connected to the base of the transistor V218, the collector of the transistor V218 is connected to the base of the transistor V217; the any key wake-up circuit includes a transistor V212 and a transistor V216, the base of the transistor V216 is connected to the power-off monitoring circuit. The test circuit is connected, the collector of the transistor V216 is connected to the base of the transistor V212; the low voltage difference standby power supply boost circuit includes a resistor R431, a resistor R432, a transistor V197 and a transistor V198, one end of the resistor R431 is connected to the third pin of the transistor V197, and the other end is connected to the base of the transistor V198, one end of the resistor R432 is connected to the first pin of the transistor V197 and the collector of the transistor V198 respectively, and the other end is connected to the external power supply V12P0_SYS.

[0028] The utility model solves the problems in the prior art of being unable to wake up by pressing any button during the wake-up process, repeated restarts and wake-up failures, and inconsistent performance at high and low temperatures and normal temperatures due to differences in device parameters.

[0029] In order to enable those skilled in the art to better understand the method of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0030] The utility model provides an arbitrary key wake-up and low voltage difference power supply switching circuit based on power failure monitoring, which is applied to the realization of power failure monitoring, backup power supply and key wake-up functions of power terminal equipment. The power failure monitoring is to detect the power supply voltage by means of a reference value of a dedicated chip or a combination of discrete components. When it is higher or lower than the detection value, the corresponding logic level is output. The key wake-up is to trigger the power supply of the terminal backup power supply by any key, wake up the terminal and meet the reporting, communication, upgrade and other tasks required by the technical specifications, and shut down automatically after meeting the specified working time. In this embodiment, combined with Figures 1 to 6 In this embodiment, the arbitrary key wake-up and low voltage difference power supply switching circuit based on power failure monitoring includes:

[0031] Power-off monitoring circuit, any key wake-up circuit and low-voltage difference standby power boost circuit; the power-off monitoring circuit includes a voltage-stabilizing diode V1, a transistor V217 and a transistor V218, the cathode of the voltage-stabilizing diode V1 is connected to the external input power supply V12P0, the anode of the voltage-stabilizing diode V1 is connected to the base of the transistor V218, and the collector of the transistor V218 is connected to the base of the transistor V217;

[0032] Furthermore, in this embodiment, the power-off monitoring circuit also includes a resistor R885, a resistor R888, a resistor R889, a capacitor C96 and a capacitor C411. One end of the resistor R885 is connected to the external input power supply V12P0, and the other end is connected to the negative electrode of the voltage-stabilizing diode V1 and one end of the capacitor C96, respectively. The other end of the capacitor C96 is grounded. One end of the resistor R889 is connected to the base of the transistor V217 and the collector of the transistor V218, respectively, and the other end is connected to one end of the resistor R888. The other end of the resistor R888 is connected to the collector of the transistor V217 and the arbitrary key wake-up circuit, respectively. One end of the capacitor C411 is connected to the arbitrary key wake-up circuit, and the other end is connected to the emitter of the transistor V217.

[0033] Specifically, the external AC / DC input power supply is assumed to be V12P0, and V1 is a Zener diode. The corresponding voltage regulation value can be selected according to actual needs. This circuit makes full use of the fixed conduction value between transistors B and E and the conduction value of the Zener diode. Combined with the selection of the corresponding current-limiting resistor (the voltage divider value when conducting needs to be considered), it can be achieved during the key wake-up process to ensure that POW_DOWN is not abnormally pulled high. The devices used in this circuit are all discrete devices, so there is no minimum operating threshold voltage value requirement required by the power chip.

[0034] The any key wake-up circuit includes a transistor V212 and a transistor V216, the base of the transistor V216 is connected to the power-off monitoring circuit, and the collector of the transistor V216 is connected to the base of the transistor V212;

[0035] Furthermore, in this embodiment, the arbitrary key wake-up circuit also includes a diode V213, a diode V214, a resistor R671, a resistor R672, a resistor R675 and a transistor V209. The positive electrode of the diode V213 is connected to the control end of the key circuit, the positive electrode of the diode V214 is connected to the CPU output end, the negative electrode of the diode V213 and the negative electrode of the diode V214 are respectively connected to one end of the resistor R672, the other end of the resistor R672 is respectively connected to the collector of the transistor V216 and the base of the transistor V212, the collector of the transistor V212 is respectively connected to one end of the resistor R671 and the first pin of the transistor V209, the base of the transistor V216 is connected to one end of the resistor R675, the other end of the resistor R675 is connected to the power-off monitoring circuit, the second pin of the transistor V209 is connected to the other end of the resistor R671, and the third pin of the transistor V2019 is connected to the backup battery.

[0036] Furthermore, in this embodiment, the key circuit includes a switch K1, a switch K2, a switch K3, a switch K4, a switch K5, a switch K6, a diode V53, a diode V220, a diode V221, a diode V223, a diode V225, and a diode V228. The switches K1, K2, K3, K4, K5, and K6 are connected in parallel. The switch K1 is connected to the cathode of the diode V53, the switch K2 is connected to the cathode of the diode V220, the switch K3 is connected to the cathode of the diode V221, the switch K4 is connected to the cathode of the diode V223, the switch K5 is connected to the cathode of the diode V225, and the switch K6 is connected to the cathode of the diode V228. The anodes of the diodes V53, V220, V221, V223, V225, and V228 are combined to output a control signal.

[0037] Specifically, the arbitrary key wake-up circuit adopts the commonly used six-key circuit. The six keys are combined and a control signal KEY_D is given after any key is pressed. When any key is pressed, KEY_D is high level, and the pressing of any key does not affect the normal logic state of other keys. POW_DOWN comes from Figure 2 In the power-off monitoring circuit, KEY_D comes from Figure 5 The status signal after any key is pressed, BATT_CTRL comes from the CPU output.

[0038] Furthermore, when the external power is normal, POW_DOWN is high level. Figure 3 When V216 is turned on, any key is pressed, although KEY_D is high, V212 cannot be turned on. Therefore, there is no abnormal wake-up of battery power supply when there is normal power. When there is no external power, POW_DOWN is low level. Figure 3 When V216 is turned off, any key is pressed, KEY_D outputs a high level, V212 is turned on, and the battery starts to output power. When the system wakes up, after POW_DOWN is determined to be the key wake-up state, BATT_CTAL outputs a continuous high level, ensuring continuous and reliable power supply from the backup battery until the wake-up time required by the technical specifications is met and the output is turned off.

[0039] The low voltage difference backup power supply boost circuit includes a resistor R431, a resistor R432, a transistor V197 and a transistor V198. One end of the resistor R431 is connected to the third pin of the transistor V197, and the other end is connected to the base of the transistor V198. One end of the resistor R432 is connected to the first pin of the transistor V197 and the collector of the transistor V198 respectively, and the other end is connected to the external power supply V12P0_SYS.

[0040] Furthermore, in this embodiment, the low voltage difference backup power supply boost circuit also includes a chip D13, a resistor R150 and a resistor R160, the 11th pin of the chip D13 is connected to the backup battery, one end of the resistor R150 is connected to the 6th pin of the chip D13, and the other end is connected to one end of the resistor R160, and the other end of the resistor R160 is connected to the 8th pin of the chip D13.

[0041] Specifically, BATT_IN is a backup battery. When the button is pressed to wake up, BATT_IN continues to output. V197, V198, R431, and R432 constitute a low-voltage difference power supply switching and low leakage current circuit. When the terminal is normally powered, V12P0_SYS is powered, and BATT_IN is out of power, D13 does not work, V197 is in a non-conducting state, and the leakage current is at the uA level; when the terminal is in a button wake-up state, D13 starts to work normally, and the corresponding boost value is set by the two matching resistors R150 and R160. At this time, V198 is turned on, thereby pulling down the G pole of V197, and V197 meets the conduction condition, thereby realizing low-voltage difference conduction.

[0042] In an arbitrary key wake-up and low-voltage difference power switching circuit based on power-off monitoring provided by an embodiment of the present invention, when the system starts working, any key of the arbitrary key wake-up circuit is pressed, and the CPU in the external power supply state continuously pulls down BATT_CTRL to determine whether the power-off signal POW_DOWN is greater than 3.3V. If so, the arbitrary key is pressed again. If not, it is determined that the CPU is in the key wake-up state, the CPU continuously pulls up BATT_CTRL, and the backup battery continues to output through the low-voltage difference backup power boost circuit until the specified backup time is reached. The CPU pulls down BATT_CTRL again, and the system shuts down and stops working.

[0043] The above-mentioned embodiment of the power-off monitoring-based arbitrary key wake-up and low-voltage difference power switching circuit is compared with the prior art. The circuit of the prior art cannot achieve arbitrary key wake-up during the wake-up process, and there are repeated restarts and wake-up failures, as well as inconsistent performance at high and low temperatures and normal temperatures due to differences in device parameters. The utility model has a simple structure and powerful functions. The power-off monitoring circuit is based on the fixed conduction value of the voltage-stabilizing diode and the transistor, and discrete components are used. It is not limited by the minimum operating voltage threshold value, and the power-off monitoring circuit operates stably and reliably. The logic circuit of the arbitrary key wake-up is set to realize the design of waking up the terminal after pressing multiple keys or any key of the terminal, and they are not affected by each other. The wake-up circuit design based on the power-off monitoring signal and CPU control logic avoids abnormal loss caused by false triggering of the backup battery power supply when normal power is available, and the circuit is simple, reliable and efficient. In the low-voltage difference backup power boost circuit, the backup battery passes through the boost chip and then passes through the low-voltage difference power switching circuit, which can meet the low-voltage difference ripple requirements of the terminal device for the interface circuit, avoiding the voltage difference uncertainty and large ripple caused by ordinary diodes.

[0044] Obviously, the embodiments described above are only preferred embodiments of the present invention, rather than all embodiments. The preferred embodiments of the present invention are given in the accompanying drawings, but they do not limit the patent scope of the present invention. The present invention can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned specific embodiments, or to make equivalent replacements for some of the technical features therein. Any equivalent structure made using the contents of the present invention specification and the accompanying drawings, directly or indirectly used in other related technical fields, is also within the scope of protection of the present invention patent.

Claims

1. A circuit for waking up by any key and switching low voltage difference power supply based on power failure monitoring, characterized in that: include: Power-off monitoring circuit, any-key wake-up circuit and low-voltage-drop backup power boost circuit; The power-off monitoring circuit includes a voltage-stabilizing diode V1, a transistor V217, and a transistor V218. The cathode of the voltage-stabilizing diode V1 is connected to the external input power supply V12P0, the anode of the voltage-stabilizing diode V1 is connected to the base of the transistor V218, and the collector of the transistor V218 is connected to the base of the transistor V217. The arbitrary key wake-up circuit includes a transistor V212 and a transistor V216. The base of the transistor V216 is connected to the power-off monitoring circuit. The transistor V2 16 is connected to the base of the transistor V212; the low voltage difference standby power supply boost circuit includes a resistor R431, a resistor R432, a transistor V197 and a transistor V198, one end of the resistor R431 is connected to the third pin of the transistor V197, and the other end is connected to the base of the transistor V198, one end of the resistor R432 is connected to the first pin of the transistor V197 and the collector of the transistor V198 respectively, and the other end is connected to the external power supply V12P0_SYS.

2. The arbitrary key wake-up and low voltage difference power supply switching circuit based on power failure monitoring according to claim 1 is characterized in that: The power-off monitoring circuit also includes a resistor R885, a resistor R888, a resistor R889, a capacitor C96 and a capacitor C411. One end of the resistor R885 is connected to the external input power supply V12P0, and the other end is connected to the negative electrode of the voltage-stabilizing diode V1 and one end of the capacitor C96, respectively. The other end of the capacitor C96 is grounded. One end of the resistor R889 is connected to the base of the transistor V217 and the collector of the transistor V218, respectively, and the other end is connected to one end of the resistor R888. The other end of the resistor R888 is connected to the collector of the transistor V217 and the arbitrary key wake-up circuit, respectively. One end of the capacitor C411 is connected to the arbitrary key wake-up circuit, and the other end is connected to the emitter of the transistor V217.

3. The arbitrary key wake-up and low voltage difference power supply switching circuit based on power failure monitoring according to claim 1 is characterized in that: The arbitrary key wake-up circuit further includes a diode V213, a diode V214, a resistor R671, a resistor R672, a resistor R675 and a transistor V209, the anode of the diode V213 is connected to the control end of the key circuit, the anode of the diode V214 is connected to the CPU output end, the cathode of the diode V213 and the cathode of the diode V214 are respectively connected to one end of the resistor R672, and the other end of the resistor R672 is connected to the transistor V213. 6 and the base of the transistor V212 are respectively connected, the collector of the transistor V212 is respectively connected to one end of the resistor R671 and the first pin of the transistor V209, the base of the transistor V216 is connected to one end of the resistor R675, the other end of the resistor R675 is connected to the power-off monitoring circuit, the second pin of the transistor V209 is connected to the other end of the resistor R671, and the third pin of the transistor V2019 is connected to the backup battery.

4. The arbitrary key wake-up and low voltage difference power supply switching circuit based on power failure monitoring according to claim 3, wherein the key circuit includes a switch K1, a switch K2, a switch K3, a switch K4, a switch K5, a switch K6, a diode V53, a diode V220, a diode V221, a diode V223, a diode V225 and a diode V228, wherein the switch K1, the switch K2, the switch K3, the switch K4, the switch K5 and the switch K6 are connected in parallel with each other, and the switch K1 and the diode V53 are connected in parallel with each other. The switch K2 is connected to the cathode of the diode V220, the switch K3 is connected to the cathode of the diode V221, the switch K4 is connected to the cathode of the diode V223, the switch K5 is connected to the cathode of the diode V225, the switch K6 is connected to the cathode of the diode V228, and the anodes of the diode V53, the diode V220, the diode V221, the diode V223, the diode V225, and the diode V228 are combined to output a control signal.

5. The arbitrary key wake-up and low voltage difference power supply switching circuit based on power failure monitoring according to claim 1, characterized in that: The low voltage difference backup power supply boost circuit also includes a chip D13, a resistor R150 and a resistor R160. The 11th pin of the chip D13 is connected to the backup battery, one end of the resistor R150 is connected to the 6th pin of the chip D13, and the other end is connected to one end of the resistor R160. The other end of the resistor R160 is connected to the 8th pin of the chip D13.

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