Single-key physical switch circuit and device

Abstract

The utility model discloses a single-key physical switch circuit and device, and relates to the field of power management, and the single-key physical switch circuit comprises a key detection circuit and an on-off circuit. The key detection circuit is respectively connected with the control end of the MCU chip and the on-off circuit; the on-off circuit is respectively connected with the key detection circuit, the first power supply and the power supply end of the MCU chip; the key detection circuit is used for outputting a conduction signal to the on-off circuit when the input key signal voltage value is greater than an expected threshold value when the key detection circuit is connected to the control end of the MCU chip; and the on-off circuit is used for conducting the connection between the first power supply and the power supply end of the MCU chip when receiving the conduction signal. The utility model aims to solve the problem that the loss current of a host power switch is too high, and a small-current touch switch can be used for replacing a large-current toggle switch to control the startup and shutdown of a host.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of power management, in particular to a single-key physical switch circuit and device. BACKGROUND

[0002] The existing machine device startup and shutdown method mostly uses a normally open and normally closed toggle switch. The toggle switch is an electrical switch that uses a lever or handle that moves before and after use to turn on or off the circuit. In the normally open and normally closed toggle switch, there are usually two or more contact positions corresponding to the normally open and normally closed states. The normally open and normally closed toggle switch is widely used in various occasions that require manual control of the circuit, such as power switches, device start / stop control, etc. The switch fluctuates to "I" startup, and the switch toggles to "O" shutdown. The defect of this startup method is that the total circuit must flow through the toggle switch, the switch bears the total current of the host, the switch is installed on the side of the machine, and the connection wire is relatively long, which can easily cause current loss. This has high requirements for the selection of the switch and the overload current of the wire. In addition, when the high-power wire is too far, there is a high risk of electromagnetic radiation interference.

[0003] Therefore, the normally open and normally closed toggle switch has some obvious limitations in the application of machine device startup and shutdown, especially when dealing with high-power current. These limitations mainly include the limitation of current carrying capacity, wire loss, electromagnetic radiation interference, and possible electrical safety problems. CONTENT OF THE UTILITY MODEL

[0004] The main purpose of the present application is to provide a single-key physical switch circuit and device, which aims to solve the problem of high current loss of the host power switch. By using a small current key to control the large current switch, the small current touch switch can replace the large current toggle switch to control the host startup and shutdown.

[0005] To achieve the above purpose, the single-key physical switch circuit provided by the present application comprises a key detection circuit and a on-off circuit.

[0006] The key detection circuit is connected with the MCU chip control end and the on-off circuit respectively; the on-off circuit is connected with the key detection circuit, the first power supply and the MCU chip power supply end respectively.

[0007] The key detection circuit is configured to input the key signal voltage value greater than the expected threshold value to the on-off circuit to output a conduction signal when the MCU chip control end is connected.

[0008] The on-off circuit is configured to connect the first power supply and the MCU chip power supply end when the conduction signal is received.

[0009] In an embodiment, the single-key physical switch circuit further comprises a control circuit;

[0010] The control circuit is connected with the detection circuit and the MCU chip control end respectively.

[0011] The control circuit is configured to receive a control signal provided by the MCU chip control end and output an open circuit signal to the on-off circuit.

[0012] The on-off circuit is configured to disconnect the first power supply and the MCU chip power end when receiving the open circuit signal.

[0013] In an embodiment, the key detection circuit comprises a first resistor, a first diode, a second diode and a key switch.

[0014] The first end of the first resistor is connected with the second power supply, and the second end of the first resistor is connected with the anode of the first diode and the MCU chip control end respectively; the anode of the second diode is connected with the on-off circuit and the control circuit respectively, and the cathode of the second diode is connected with the cathode of the first diode and the first end of the key switch respectively; the second end of the key switch is grounded.

[0015] In an embodiment, the control circuit comprises a second resistor, a third resistor and a first triode.

[0016] The first end of the second resistor is connected with the first end of the third resistor and the base of the first triode respectively, the second end of the second resistor is connected with the MCU chip control end, and the second end of the third resistor is grounded; the collector of the first triode is connected with the key detection circuit and the on-off circuit respectively, and the emitter of the first triode is grounded.

[0017] In an embodiment, the on-off circuit comprises a voltage dividing circuit and a PMOS tube.

[0018] The voltage dividing circuit is connected with the first power supply, the control circuit and the key detection circuit respectively, and the PMOS tube is connected with the voltage dividing circuit, the first power supply and the MCU chip power end respectively.

[0019] The voltage dividing circuit is configured to receive a voltage signal input by the first power supply, divide the voltage signal and obtain a divided voltage signal.

[0020] The PMOS tube is configured to maintain the connection between the first power supply and the MCU chip power end when the value of the divided voltage signal is lower than a switch threshold.

[0021] The PMOS tube is also configured to disconnect the first power supply from the MCU chip power terminal when receiving the off signal output by the control circuit.

[0022] In an embodiment, the voltage dividing circuit comprises a fourth resistor and a fifth resistor.

[0023] The first end of the fourth resistor is connected to the first power supply, and the second end of the fourth resistor is connected to the first end of the fifth resistor and the gate of the PMOS tube.

[0024] In an embodiment, the gate of the PMOS tube is connected to the second end of the fourth resistor and the first end of the fifth resistor, the source of the PMOS tube is connected to the first end of the fourth resistor and the first power supply, and the drain of the PMOS tube is connected to the MCU chip power terminal.

[0025] In an embodiment, the circuit of the single-key physical switch further comprises a filter circuit.

[0026] The filter circuit is connected to the on-off circuit and the first power supply.

[0027] The filter circuit is configured to filter the voltage signal output by the first power supply and transmit the filtered voltage signal to the on-off circuit.

[0028] In an embodiment, the filter circuit comprises a first capacitor and a second capacitor.

[0029] The first end of the first capacitor is connected to the first power supply and the source of the PMOS tube, the first end of the second capacitor is connected to the MCU chip power terminal and the drain of the PMOS tube, and the second end of the first capacitor is grounded.

[0030] To achieve the above-mentioned purposes, the application further provides a single-key physical switch device, which comprises the single-key physical switch circuit.

[0031] The above-mentioned one or more technical solutions provided by the application can have the following advantages or at least achieve the following technical effects:

[0032] The application discloses a single-key physical switch circuit and device, and relates to the field of power management. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only represent some of the embodiments of the present application, and the other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0034] Figure 1 FIG. 1 is a functional schematic diagram of a first embodiment of the single-key physical switch circuit according to the present application;

[0035] Figure 2 FIG. 2 is a circuit schematic diagram of a second embodiment of the single-key physical switch circuit according to the present application;

[0036] Figure 3 FIG. 3 is a schematic diagram of a filter circuit of the single-key physical switch circuit according to the present application.

[0037] LIST OF ELEMENTS IN THE DRAWINGS

[0038] Reference Name Reference Name 1 MCU chip control end 2 MCU chip power supply end 10 Key detection circuit 20 On-off circuit 30 Control circuit 21 Voltage division circuit 40 Filter circuit Q1 PMOS tube D1~D2 First diode to second diode C1~C2 First capacitor to second capacitor R1~R5 First resistor to fifth resistor T1 First triode VCC First power supply VCC_3.3V Second power supply SW Key switch

[0039] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the accompanying drawings. Obviously, the described embodiments only represent some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without any creative effort belong to the scope of protection of the present application.

[0041] It should be noted that if the application embodiments involve directionality indications (such as up, down, left, right, front, back, etc.), the directionality indications are only used to explain the relative position relationship, motion condition, etc. between components in a certain posture, and if the certain posture changes, the directionality indications will also change accordingly.

[0042] In addition, if the application embodiments involve descriptions such as "first", "second", etc., the descriptions of "first", "second", etc. are only for description purposes and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of indicated technical features. Therefore, the features limited by "first" and "second" can explicitly or implicitly include at least one of the features. In addition, "and / or" or "and / or" appearing throughout the text means that the three parallel schemes are included, for example, "A and / or B" includes A scheme, or B scheme, or A and B simultaneously satisfy the scheme. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of ordinary skilled in the art, when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, nor within the protection scope claimed by the present application.

[0043] The main solution involved in the present application is a single-key physical switch circuit, which is a commonly used circuit design that allows users to turn on and off the device through a single key. This circuit design usually involves power management, logic control, and possible feedback mechanisms. The toggle switch is used as a control signal source, rather than directly carrying the main loop current. A low-current auxiliary circuit is controlled by the toggle switch, which in turn drives the relay or contactor to close or open the main loop. In this way, the main loop current no longer flows through the toggle switch, but through the contacts of the relay or contactor, which are usually designed to withstand higher currents.

[0044] Based on this, the single-key physical switch circuit provided by the present application aims to solve the problem of high power consumption of the host power switch, and can realize the replacement of the large-current toggle switch with a small-current touch switch to control the host power on and off. This circuit realizes single-key power on, optimizes the key selection requirements, and reduces the risk of electromagnetic interference caused by long detour of large current.

[0045] Reference Figure 1 , Figure 1 is a functional schematic diagram of the first embodiment of the single-key physical switch circuit according to the present application.

[0046] The single-key physical switch circuit comprises a key detection circuit 10 and a on-off circuit 20; the key detection circuit 10 is connected with an MCU chip control end 1 and the on-off circuit 20 respectively; the on-off circuit 20 is connected with the key detection circuit 10, a first power supply VCC and an MCU chip power supply end 2 respectively;

[0047] The key detection circuit 10 is configured to output a conduction signal to the on-off circuit 20 when the input key signal voltage value is greater than the expected threshold value at the MCU chip control end 1.

[0048] The on-off circuit 20 is configured to turn on the connection between the first power supply VCC and the MCU chip power supply end 2 when the conduction signal is received.

[0049] Specifically, the on-off circuit 20 uses a switch tube as a power control switch, and controls the conduction and cut-off of the switch tube through the key switch SW of the light touch key detection circuit 10, so as to realize the on-off function of the host. A key advantage of this circuit design is that the key switch SW of the light touch key detection circuit 10 is turned on during this operation process, and the current flowing through the circuit is very small, which reduces the requirements for wire specifications and installation positions, realizes the use of small-current light touch switches to replace large-current toggle switches to control the on-off of the host, and also reduces the risk of electromagnetic interference. Generally, the switch tube of the on-off circuit 20 can be selected from MOSFET or IGBT, wherein MOSFET (Metal Oxide Semiconductor Field Effect Transistor) is a widely used electronic component, especially in integrated circuits and power electronics. The main function of MOSFET is to change its conductivity by controlling the input voltage (gate voltage), so as to control the current flowing through it. MOSFET is widely used in various electronic devices due to its high input impedance, low on-resistance, easy integration and high-speed switching capability. IGBT (Insulated Gate Bipolar Transistor) is a composite full-control voltage-driven power semiconductor device composed of a bipolar transistor and an insulated gate field effect transistor. The on and off of the high-current path can be controlled by a control signal, and these electronic switches usually have low on-resistance, which can reduce energy consumption. Here, the PMOS tube is selected as the switch tube of the on-off circuit 20 to control the on-off of the circuit.

[0050] In particular, it is necessary to explain that the expected threshold is the threshold voltage value Vth presetting the conduction voltage of the diode of the key detection circuit 10, the voltage value of the key signal is the voltage value of the "MCU_POWER_CTL" pin of the MCU chip control end 1 for access, and the conduction signal is the signal sent by the key detection circuit 10 to the on-off circuit 20 for controlling the connection between the first power supply VCC and the MCU chip power supply end 2. The on-off circuit 20 adopts a PMOS tube Q1 as a main switch tube, and realizes the on-off of the circuit by controlling the gate-source voltage Vgs thereof. The key switch SW is pressed to cooperate with the voltage dividing resistors R4 and R5 and the second diode D2 to form a circuit path for controlling the conduction of the PMOS tube. When the SW is pressed, the voltage dividing through the resistors makes the Vgs of the PMOS tube less than the threshold voltage of the PMOS tube, so that the PMOS tube Q1 is turned on, and the first power supply VCC provides the working voltage for the MCU chip power supply end 2.

[0051] Based on the first embodiment of the present application, the same or similar contents as the above embodiment one can be referred to the above description, and the subsequent description will not be repeated. On this basis, please refer to Figure 2 , Figure 2 is the circuit schematic diagram of the single-key physical switch circuit embodiment provided by the embodiment of the utility model.

[0052] In the embodiment, the key detection circuit 10 comprises a first resistor R1, a first diode D1, a second diode D2 and a key switch SW.

[0053] The first end of the first resistor R1 is connected with the second power supply VCC_3.3V, and the second end of the first resistor R1 is connected with the anode of the first diode D1 and the MCU chip control end 1 respectively; the anode of the second diode D2 is connected with the on-off circuit 20 and the control circuit 30 respectively, and the cathode of the second diode D2 is connected with the cathode of the first diode D1 and the first end of the key switch SW respectively; and the second end of the key switch SW is grounded.

[0054] Specifically, in the embodiment, the key detection circuit 10 forms a closed loop through the first resistor R1, the first diode D1 and the key switch SW, and when the key switch SW is pressed, the "MCU_POWER_KEY_DEC" pin of the MCU chip control end 1 is pulled down to a low potential, triggering the shutdown or startup response of the MCU chip. This design utilizes the unidirectional conductivity of the diode, preventing the current from flowing reversely into the pin of the MCU chip when the key switch SW is not pressed. The key detection circuit 10 is composed of the first resistor R1, the first diode D1, the second diode D2, the key switch SW and the related connection lines, and its main function is to detect the state of the key switch SW and convert the state into a voltage signal recognizable by the MCU.

[0055] After detecting the low level signal of the "MCU_POWER_KEY_DEC" pin, the MCU outputs a high level by controlling the "MCU_POWER_CTL" pin, and the high level signal drives the first triode T1 to be turned on. It should be noted that although the first triode T1 is turned on in the case that the PMOS tube Q1 has been turned on, this process is not necessary to maintain the voltage of the MCU chip power terminal 2. However, when the key switch SW is released at this time, the key detection circuit 10 is disconnected, the first triode T1 is still turned on, and the PMOS tube Q1 will always be maintained in the turned-on state, the host completes the startup, and the "MCU_POWER_KEY_DEC" pin changes from low level to high level.

[0056] Further, in the embodiment, the on-off circuit 20 includes a voltage dividing circuit 21 and a PMOS tube Q1; wherein the voltage dividing circuit 21 is connected with the first power supply VCC, the control circuit 30 and the key detection circuit 10 respectively, and the PMOS tube Q1 is connected with the voltage dividing circuit 21, the first power supply VCC and the MCU chip power terminal 2 respectively.

[0057] The voltage dividing circuit 21 is configured to receive a voltage signal input by the first power supply VCC and divide the voltage signal to obtain a divided voltage signal.

[0058] The PMOS tube Q1 is configured to open the connection between the first power supply VCC and the MCU chip power terminal 2 when receiving a value of the divided voltage signal lower than a switch threshold value.

[0059] The PMOS tube Q1 is further configured to disconnect the connection between the first power supply VCC and the MCU chip power terminal 2 when receiving a disconnect signal output by the control circuit 30.

[0060] It is easy to understand that in the embodiment, due to the voltage division of the fourth resistor R4 and the fifth resistor R5 in the voltage dividing circuit 21, the gate-source voltage Vgs of the PMOS tube Q1 is less than the threshold voltage Vth, so the PMOS tube Q1 is turned on. The turn-on of the PMOS tube Q1 makes the voltage of the first power supply VCC transmitted to the MCU chip power terminal 2. With the rise of the voltage of the MCU chip power terminal 2, the MCU chip is powered on and enters the startup process.

[0061] When the host computer is powered on and needs to be powered off, the key switch SW needs to be pressed again and released. At this time, the key detection circuit 10 forms a loop and starts to work, and the "MCU_POWER_KEY_DEC" pin of the MCU chip control end 1 is pulled low to a low potential. After the MCU chip detects the low potential of the "MCU_POWER_KEY_DEC" pin, it controls the output pin "MCU_POWER_CTL" to output a high level signal, the first triode T1 is cut off, the control circuit 30 outputs an open circuit signal to the on-off circuit 20, the PMOS tube Q1 is cut off and the connection between the first power supply VCC and the MCU chip power supply end 2 is disconnected, and the host computer is powered off.

[0062] Further, in this embodiment, before power-on, the PMOS tube Q1 is in the off state, the MCU chip power supply end 2 has no voltage input, and the host computer is in a long-term power-off state.

[0063] The detailed process of power-on is that when the user presses the key switch SW to power on, the second diode D2 of the key detection circuit 10 is forward-biased. At this time, the fourth resistor R4, the fifth resistor R5, the second diode D2 and the key switch SW together form a complete current path. Since the fourth resistor R4 and the fifth resistor R5 of the voltage dividing circuit 21 divide the voltage between the gate and the source of the PMOS tube Q1, and the division result makes the gate-source voltage Vgs less than 0V (for PMOS tube, Vgs less than 0V is on), therefore the PMOS tube Q1 is turned on. The conduction of Q1 makes the voltage of VCC transmitted to the MCU chip power supply end 2, thereby providing working voltage for the MCU chip power supply end 2.

[0064] With the rising of the voltage of the MCU chip power supply end 2, the MCU chip starts to work. In the starting process of the MCU chip, the voltage change on the "MCU_POWER_KEY_DEC" pin of the MCU chip control end 1 is detected. Since the first resistor R1, the first diode D1 and the key switch SW form a current loop, when the key switch SW is pressed, the "MCU_POWER_KEY_DEC" pin is pulled low to the ground potential (or close to the ground potential), and the MCU chip detects the low level signal.

[0065] Once the MCU chip detects that the "MCU_POWER_KEY_DEC" pin is low, it outputs a high signal through its output pin "MCU_POWER_CTL". This high signal drives the NPN transistor to turn on. The user releases the key switch SW, and the "MCU_POWER_KEY_DEC" pin will change from low to high. SW no longer directly pulls the pin low, but because the transistor T1 has already turned on (and Q1 remains on), the voltage at the MCU chip power supply terminal 2 is still stable, and the host remains powered on.

[0066] The detailed shutdown process is as follows: when the user wants to turn off the host, the key switch SW is pressed again. The key detection circuit 10 pulls the "MCU_POWER_KEY_DEC" pin low to send a shutdown request to the MCU chip.

[0067] The MCU chip responds to the shutdown request. After the MCU chip detects the low signal of the "MCU_POWER_KEY_DEC" pin, it outputs a low signal through the "MCU_POWER_CTL" pin to turn off the NPN transistor T1 of the control circuit 30. However, in the design of "pressing the key switch SW again without releasing", the turn-off of T1 does not directly cause the turn-off of PMOS Q1, because the on state of Q1 depends more on the closed loop formed by the voltage divider circuit 21, the second diode D2, and the key switch SW. However, for the sake of design integrity, this step ensures that T1 does not interfere with the state of PMOS Q1 even without other logic control.

[0068] After releasing the key switch SW, the loop is disconnected, and the "MCU_POWER_KEY_DEC" pin generates a trigger signal that changes from high to low. After the MCU detects that the pin is low, the output pin "MCU_POWER_CTL" is low, the NPN transistor Q7 is turned off, and the PMOS transistor Q1 is turned off. In fact, the pull-down of the "MCU_POWER_CTL" pin is usually achieved by other mechanisms inside the MCU chip. However, in this description, the MCU chip ensures that the Vgs voltage of PMOS Q1 no longer meets the turn-on condition while outputting a low level to "MCU_POWER_CTL", thereby turning off PMOS Q1. With the turn-off of PMOS Q1, the MCU chip power supply terminal 2 no longer receives the voltage output by the first power supply VCC, so the voltage at the MCU chip power supply terminal 2 drops to zero, and the host is powered off.

[0069] Based on the first embodiment and / or the second embodiment of the present application, in the third embodiment of the present application, the same or similar contents as the above-mentioned first embodiment and second embodiment can be referred to the above description, and the subsequent description will not be repeated. On this basis, please refer to Figure 3 , Figure 3 is a schematic diagram of the single-key physical switch circuit with a filter circuit according to the embodiments of the present application.

[0070] The single-key physical switch circuit further comprises a filter circuit 40. It is easy to understand that in the present embodiment, there is high-frequency noise caused by external circuits in the voltage signal output by the first power supply VCC. Therefore, a low-pass filter circuit 40 can be arranged between the output end of the first power supply VCC and the on-off circuit 20 and the power supply end 2 of the MCU chip, respectively, to perform low-pass filtering on the voltage signal, so as to ensure the accuracy of the voltage signal received by the on-off circuit 20.

[0071] In addition, in order to achieve the above-mentioned purpose, the embodiments of the present application further provide a single-key physical switch device using all the embodiments of the single-key physical switch circuit as described above. Compared with the prior art, the single-key physical switch device provided by the embodiments of the present application has the same beneficial effects as the single-key physical switch circuit provided by the above-mentioned embodiments, and the other technical features of the single-key physical switch device are the same as the features disclosed in the above-mentioned embodiments, which will not be repeated here.

[0072] The above is only the preferred embodiment of the present application, and does not limit the scope of the present application. Any equivalent structure or equivalent process transformation based on the content of the present application specification and drawings, or direct or indirect application in other related technical fields, are also included in the processing range of the present application.

Claims

1. A single button physical switch circuit, characterized by, The single-key physical switch circuit comprises a key detection circuit and a on-off circuit. The key detection circuit is connected with the MCU chip control end and the on-off circuit. The key detection circuit outputs a conduction signal to the on-off circuit when the input key signal voltage value is greater than the expected threshold value. The on-off circuit turns on the connection between the first power supply and the MCU chip power supply end when receiving the conduction signal. The single-key physical switch circuit further comprises a control circuit.

2. The single-key physical switch circuit of claim 1, wherein, The control circuit is connected with the detection circuit and the MCU chip control end. The control circuit receives the control signal provided by the MCU chip control end and outputs a disconnection signal to the on-off circuit. The on-off circuit disconnects the connection between the first power supply and the MCU chip power supply end when receiving the disconnection signal. The key detection circuit comprises a first resistor, a first diode, a second diode and a key switch.

3. The single-key physical switch circuit of claim 2, wherein, The first end of the first resistor is connected with the second power supply, the second end of the first resistor is connected with the anode of the first diode and the MCU chip control end, the anode of the second diode is connected with the on-off circuit and the control circuit, the cathode of the second diode is connected with the cathode of the first diode and the first end of the key switch, and the second end of the key switch is grounded. The control circuit comprises a second resistor, a third resistor and a first triode.

4. The single-key physical switch circuit of claim 3, wherein, The first end of the second resistor is connected with the first end of the third resistor and the base of the first triode, the second end of the second resistor is connected with the MCU chip control end, the second end of the third resistor is grounded, the collector of the first triode is connected with the key detection circuit and the on-off circuit, and the emitter of the first triode is grounded. The on-off circuit comprises a voltage division circuit and a PMOS tube.

5. The single-button physical switch circuit of claim 4, wherein, The voltage division circuit is connected with the first power supply, the control circuit and the key detection circuit, and the PMOS tube is connected with the voltage division circuit, the first power supply and the MCU chip power supply end. The voltage division circuit receives the voltage signal input by the first power supply and divides the voltage signal to obtain a divided voltage signal. The PMOS tube maintains the connection between the first power supply and the MCU chip power supply end when receiving the value of the divided voltage signal which is lower than the switch threshold value. The PMOS tube disconnects the connection between the first power supply and the MCU chip power supply end when receiving the disconnection signal output by the control circuit. The voltage division circuit comprises a fourth resistor and a fifth resistor.

6. The single-key physical switch circuit of claim 5, wherein, ​ The first end of the fourth resistor is connected with the first power supply, and the second end of the fourth resistor is connected with the first end of the fifth resistor and the gate of the PMOS tube.

7. The single-button physical switch circuit of claim 6, wherein, The gate of the PMOS tube is connected with the second end of the fourth resistor and the first end of the fifth resistor, the source of the PMOS tube is connected with the first end of the fourth resistor and the first power supply, and the drain of the PMOS tube is connected with the power supply end of the MCU chip.

8. The single-key physical switch circuit of claim 7, wherein, The circuit of the single-key physical switch further comprises a filter circuit. The filter circuit is connected with the on-off circuit and the first power supply. The filter circuit is configured to filter the voltage signal output by the first power supply and transmit the filtered voltage signal to the on-off circuit.

9. The single-button physical switch circuit of claim 8, wherein, The filter circuit comprises a first capacitor and a second capacitor. The first end of the first capacitor is connected with the first power supply and the source of the PMOS tube, the first end of the second capacitor is connected with the power supply end of the MCU chip and the drain of the PMOS tube, and the second end of the first capacitor is grounded.

10. A single button physical switch device, characterized by, The single-key physical switch device comprises the single-key physical switch circuit according to any one of claims 1 to 9.

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