Startup and shutdown circuit, circuit board and electronic equipment

Abstract

The utility model provides a startup and shutdown circuit, a circuit board and electronic equipment, and relates to the technical field of electronic devices.According to the scheme, enabling control over a DCDC module is achieved by controlling output of an enabling signal through an enabling control module in the circuit through a switch key, so that quick startup of the DCDC module can be achieved by pressing the switch key, and the startup efficiency is improved. And the circuit can thoroughly cut off the power supply of the battery after the equipment is shut down through the switch key, so that the protection on the electric quantity of the battery is effectively realized.

Description

Technical Field

[0001] The present application relates to the technical field of electronic circuits, and in particular to a switch circuit, a circuit board and an electronic device. Background Art

[0002] Electronic devices such as recording and broadcasting hosts, laptops, etc. can be powered by built-in batteries, or connected to an external power source through an adapter. When no external power source is connected, the device can be powered by the built-in battery, such as the device operates normally when powered by the built-in battery, or the device is powered by the battery when in standby mode.

[0003] In order to achieve fast startup, the related technology will put the device in standby mode when powered by a battery, but the battery will continue to discharge when the device is in standby mode, that is, there is standby power consumption on the battery, which makes the battery power be consumed faster. In the case of low frequency of use of the device, the standby power consumption causes the battery to continue to discharge, resulting in a decrease in battery power, which makes it easy for the device to need to be charged before it can be used after it is turned on again. Utility Model Content

[0004] The present application provides a power on / off circuit, a circuit board and an electronic device, which solves the problem in the related art that battery power is easily consumed in order to quickly start up the electronic device. The present solution can effectively protect the battery power, so that the electronic device can start up quickly while reducing the loss of battery power.

[0005] In a first aspect, the present application provides a power on / off circuit, which includes a DCDC module, an MCU module, an enable control module, a switch button, and a button detection module.

[0006] The power supply end of the DCDC module is used to connect the output end of the battery module and the power adapter interface, and the DCDC module is also used to convert the input voltage in the working state;

[0007] The power supply end of the MCU module is connected to the output end of the DCDC module, and the signal output end of the MCU module is connected to the enable end of the DCDC module. The MCU module is used to output a latch signal to the enable end of the DCDC module after power-on or stop outputting the latch signal when receiving a key detection signal;

[0008] The first power supply end of the enabling control module is used to connect to the output end of the battery module, the second power supply end of the enabling control module is used to connect to the power adapter interface, the output end of the enabling control module is connected to the enabling end of the DCDC module, and the enabling control module is used to output an enabling signal to the enabling end of the DCDC module through the output end of the enabling control module when the control end of the enabling control module is connected to a pressing signal, so that the DCDC module is in a working state;

[0009] A first end of the switch button is grounded, a second end of the switch button is connected to a control end of the enabling control module, and the switch button is used to output a pressing signal to the control end of the enabling control module in a closed state;

[0010] The input end of the key detection module is connected to the second end of the switch key, and the output end of the key detection module is connected to the signal detection end of the MCU module. The key detection module is used to output a key detection signal to the MCU module when the switch key is in a closed state.

[0011] Therefore, in this solution, the power on / off circuit can respond to the state of the switch button to enable the DCDC module, so as to provide the user with a one-key power on / off function. While effectively achieving fast startup, it can also disconnect the battery power supply before the device is turned on and after it is turned off, thereby protecting the battery power. There is no need to continuously consume the battery power to achieve fast startup, which helps to avoid the situation where the device needs to be charged before it can be used after it is turned on again.

[0012] In one embodiment, the enabling control module includes an access unit, a control unit, and an enabling output unit;

[0013] The first input end of the access unit is used as a first power supply end of the enabling control module, and the second input end of the access unit is used as a second power supply end of the enabling control module;

[0014] The input end of the control unit is connected to the output end of the access unit, the output end of the control unit is connected to the input end of the enable output unit, and the control end of the control unit serves as the control end of the enable control module and is connected to the second end of the switch button;

[0015] The output end of the enable output unit serves as the output end of the enable control module and is connected to the enable end of the DCDC module. The enable output unit is used to output an enable signal to the DCDC module when the input end of the enable output unit is connected to a high level voltage.

[0016] Therefore, the power on / off circuit responds to the state of the switch button through the enable control module, so that during the power on process, in response to the closed state of the switch button, the enable control module provides an enable signal to the enable end of the DCDC module so that the DCDC module outputs the operating voltage.

[0017] In one embodiment, the access unit includes a first voltage-dividing resistor, a second voltage-dividing resistor, and a dual-channel diode;

[0018] The first end of the first voltage-dividing resistor serves as the first input end of the access unit, and the second end of the first voltage-dividing resistor is connected to the first input end of the dual-channel diode;

[0019] The first end of the second voltage-dividing resistor serves as the second input end of the access unit, and the second end of the second voltage-dividing resistor is connected to the second input end of the dual-channel diode;

[0020] The output end of the dual-channel diode serves as the output end of the access unit and is connected to the input end of the control unit. The dual-channel diode is used to output a high-level voltage to the input end of the control unit when a high-level voltage is connected to any input end.

[0021] Therefore, while the access unit transmits the power supply voltage to the control unit, it also plays a role in preventing backflow, so as to prevent the connected power supply from generating a backflow voltage to another power supply.

[0022] In one embodiment, the dual-channel diode is replaced by two first diodes, the anode terminals of the two first diodes serve as an input terminal respectively, and the cathode terminals of the two first diodes are connected to serve as an output terminal.

[0023] In one embodiment, the enable output unit includes a second diode, the anode end of the second diode serves as the input end of the enable output unit and is connected to the output end of the control unit; the cathode end of the second diode serves as the output end of the enable output unit and is connected to the input end of the DCDC module.

[0024] In one embodiment, the control unit includes a third voltage-dividing resistor, a fourth voltage-dividing resistor, a fifth voltage-dividing resistor, a first filter capacitor and an NPN transistor;

[0025] The first end of the third voltage-dividing resistor is used as the input end of the control unit and is connected to the output end of the access unit, the second end of the third voltage-dividing resistor is connected to the first end of the first filter capacitor, and the second end of the first filter capacitor is grounded;

[0026] The first end of the fourth voltage-dividing resistor is connected to the second end of the third voltage-dividing resistor, and the first end of the fourth voltage-dividing resistor serves as the control end of the control unit and is connected to the second end of the switch button, and the second end of the fourth voltage-dividing resistor is connected to the base end of the NPN transistor;

[0027] The first end of the fifth voltage-dividing resistor is connected to the first end of the third voltage-dividing resistor, the second end of the fifth voltage-dividing resistor is connected to the collector end of the NPN transistor, the collector end of the NPN transistor serves as the output end of the control unit and is connected to the first input end of the enable output unit, and the emitter end of the NPN transistor is grounded.

[0028] Therefore, the conduction state of the NPN transistor in the control unit is controlled by the switch button, thereby enabling the enable end of the DCDC module, effectively realizing the one-button power on and off function, and the device can completely shut down the battery power after shutting down and before the next startup, thereby effectively protecting the battery power.

[0029] In one embodiment, the key detection module includes a third diode, an anode end of the third diode is connected to the second end of the switch key, and a cathode end of the third diode is connected to the signal detection end of the MCU module.

[0030] Therefore, the MCU module can quickly determine the state of the switch button, so that when the switch button is in the closed state, the MCU module promptly releases the signal latch of the enable end of the DCDC module, which helps to disconnect the power supply in time and save the battery power.

[0031] In one embodiment, a fourth diode is further provided at the signal output end of the MCU module, the anode end of the fourth diode is connected to the signal output end of the MCU module, and the cathode end of the fourth diode is connected to the enable end of the DCDC module. The fourth diode is used to prevent voltage from flowing back to the signal output end of the MCU module.

[0032] Therefore, the fourth diode can protect the signal output end of the MCU module, thereby avoiding the occurrence of voltage backflow.

[0033] In a second aspect, the present application also provides a circuit board, which includes the power on / off circuit as described above.

[0034] In a third aspect, the present application also provides an electronic device, which includes the circuit board as described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A principle block diagram of a power on / off circuit provided in one embodiment of the present application;

[0036] Figure 2 A schematic diagram of the circuit structure of an access unit provided in one embodiment of the present application;

[0037] Figure 3 A schematic diagram of the circuit structure of a control unit provided in one embodiment of the present application;

[0038] Figure 4 A schematic diagram of the circuit structure of a power on / off circuit provided in one embodiment of the present application.

[0039] Reference numerals:

[0040] DCDC module 110 , enable control module 120 , key detection module 130 , MCU module 140 , switch key 150 , battery module 210 , power adapter interface 220 . DETAILED DESCRIPTION

[0041] The embodiments of the present application are further described in detail below in conjunction with the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are only used to explain the embodiments of the present application, rather than to limit the embodiments of the present application. It should also be noted that, for ease of description, only the parts related to the embodiments of the present application rather than all structures are shown in the accompanying drawings, and those skilled in the art should be able to think of it after reading the specification of this application that as long as the technical features do not contradict each other, any combination of the technical features can constitute an optional implementation method.

[0042] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable when appropriate, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally a class, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally represents that the objects associated before and after are in an "or" relationship. In the description of the present application, "multiple" means two or more, and "several" means one or more.

[0043] Electronic devices such as recording and broadcasting hosts and laptop computers (hereinafter referred to as devices) are usually equipped with battery power supply, external power supply and other methods. However, when the external power supply is not connected, in order to quickly start up, the relevant technology will put the device in standby mode when powered by the battery, and then the battery will continue to discharge to maintain power to the device, resulting in a large loss of battery power, and it is easy for the device to need to be charged before it can be used after it is turned on again due to insufficient power.

[0044] In the related art, the device can be controlled to enter low power consumption mode by software switch, that is, by using software program, but the functional devices in the device that maintain the program operation are still in working state, that is, the battery is still in a state of large power loss, and this method fails to effectively protect the battery power. In addition, in the related art, it can also be implemented by hardware circuit control, such as setting a switch circuit in the circuit board of the device, but the switch circuit provided in the related art does not take into account the loss of battery power by the device, that is, the device will still remain in the battery-powered state when it is not turned on, thereby exacerbating the loss of battery power.

[0045] In this regard, the present application scheme provides a power switch circuit, which can be applied to electronic devices. The power switch circuit can be connected to the power supply voltage through a battery module or an external power supply, that is, the power switch circuit can be powered by a battery module or connected to an external power supply through a power adapter. It can be imagined that there are corresponding ports on the power switch circuit to connect the corresponding power supply (such as a battery module or an external power supply). Figure 1 A schematic diagram of a power on / off circuit according to an embodiment of the present application is shown in FIG. Figure 1 As shown, the on / off circuit includes a DCDC module 110 , an enable control module 120 , a key detection module 130 , an MCU module 140 and a switch key 150 .

[0046] Among them, the DCDC module 110 is used as a power management module, and its power supply end can be used to connect the output end of the battery module 210 and the power adapter interface 220. The output end of the DCDC module 110 is connected to the power supply end of the MCU module 140 to provide the circuit with a working voltage, that is, the DCDC module 110 is used to convert the input voltage in the working state, such as boosting or bucking, so that the output voltage meets the circuit's working voltage requirements. It should be conceivable that other modules or devices that need to access the working voltage can also be connected to the output end of the DCDC module 110.

[0047] The enable end of the DCDC module 110 is connected to the output end of the enable control module 120 and the signal output end of the MCU module 140, so as to enable the DCDC module 110 through the enable control module 120 or keep the circuit working normally through the latch signal output by the MCU module 140. The enable control module 120 can also be used to connect to the battery module 210 or an external power supply, such as the first power supply end of the enable control module 120 is used to connect to the output end of the battery module 210, and the second power supply end of the enable control module 120 is used to connect to the power adapter interface 220. The control end of the enable control end is connected to one end of the switch button 150, wherein the first end of the switch button 150 is grounded, and the second end of the switch button 150 is connected to the second end of the enable control module 120. When the switch button 150 is in a closed state, the control end of the enable control module 120 can receive a pressing signal, thereby outputting an enable signal to the enable end of the DCDC module 110 through the output end of the enable control module 120, thereby making the DCDC module 110 that receives the enable signal in a working state.

[0048] In addition, the input end of the key detection module 130 is connected to the second end of the switch key 150, and the signal detection end of the MCU module 140 is connected to the output end of the key detection module 130, so that when the switch key 150 is in a closed state, the key detection module 130 can output a key detection signal to the MCU module 140. Moreover, since the signal output end of the MCU module 140 is connected to the enable end of the DCDC module 110, when the MCU module 140 receives the key detection signal, the MCU module 140 stops outputting the latch signal to the DCDC module 110.

[0049] In the case of battery power supply, when the switch button 150 is pressed and is in a closed state (i.e., the device is turned on), the control end of the enable control module 120 receives the press signal, and the enable control module 120 outputs an enable signal to the enable end of the DCDC module 110, so that the DCDC module 110 is in a working state, thereby supplying power to the MCU module 140. After the MCU module 140 works, it will output a latch signal to the enable end of the DCDC module 110 to keep the device working normally. When the switch button 150 is not pressed, the enable control module 120 fails to output an enable signal to the enable end of the DCDC module 110, so the DCDC module does not start working, and accordingly, the battery power will not be consumed.

[0050] When the switch button 150 is pressed again after the device has been turned on (i.e., the device is turned off), the MCU module 140 can detect through the button detection module 130 that the switch button 150 is in a closed state, and the MCU module 140 stops outputting the latch signal to the DCDC module 110, thereby releasing the signal latch on the enable end of the DCDC module 110, thereby disconnecting the battery power supply, effectively preserving the battery power.

[0051] In this solution, the power on / off circuit can respond to the state of the power button to enable the DCDC module, so as to provide the user with a one-button power on / off function. While effectively achieving fast startup, it can also disconnect the battery power supply before the device is turned on and after it is turned off, thereby protecting the battery power. There is no need to continuously consume the battery power to achieve fast startup, which helps to avoid the situation where the device needs to be charged before it can be used after it is turned on again.

[0052] In some embodiments, the enabling control module includes an access unit, a control unit, and an enabling output unit, wherein the access unit is used to access a power supply such as a battery, an external power supply, etc., such as the first input end of the access unit serves as the first power supply end of the enabling control module to connect to the output end of the battery module; the second input end of the access unit serves as the second power supply end of the enabling control module to connect to the power adapter interface.

[0053] The control unit is a device unit that responds to the state of the switch button. The input end of the control unit is connected to the output end of the access unit, the control end of the control unit is connected to the second end of the switch button, and the output end of the control unit is connected to the input end of the enable output unit. The control end of the control unit serves as the control end of the enable control module. When the switch button is pressed to switch to a closed state, the control unit can respond to the state change of the switch button and then switch the voltage state of the output signal, such as switching the output signal from a low-level signal to a high-level signal.

[0054] The output end of the enable output unit serves as the output end of the enable control module, and the output end of the enable output unit is connected to the enable end of the DCDC module to output an enable signal to the DCDC module when the input end of the enable output unit is connected to a high level voltage.

[0055] The power on / off circuit responds to the state of the switch button through the enable control module, so that during the power on process, in response to the closed state of the switch button, the enable control module provides an enable signal to the enable end of the DCDC module, so that the DCDC module outputs the operating voltage.

[0056] Figure 2 A schematic diagram of the circuit structure of an access unit provided in an embodiment of the present application is shown in FIG. Figure 2 As shown, in one embodiment, the access unit includes a first voltage-dividing resistor R1, a second voltage-dividing resistor R2 and a dual-channel diode D1.

[0057] The first end of the first voltage-dividing resistor R1 serves as the first input end of the access unit for connecting to the output end of the battery module, and the second end of the first voltage-dividing resistor R1 is connected to the first input end of the dual-channel diode D1. The first end of the second voltage-dividing resistor R2 serves as the second input end of the access unit for connecting to the power adapter interface, and the second end of the second voltage-dividing resistor R2 is also connected to the second input end of the dual-channel diode D1. The output end of the dual-channel diode D1 is connected to the input end of the control unit. The dual-channel diode D1 is used to output a high-level voltage to the input end of the control unit when any input end is connected to a high level.

[0058] It is understandable that the access unit can be connected to the battery module and the power adapter interface through the input terminal thereon, thereby providing the circuit with the corresponding power supply voltage. In addition, while the access unit transmits the power supply voltage to the control unit through the dual-channel diode D1, it also plays a role in preventing backflow, so as to prevent the connected power supply from generating backflow voltage to another power supply.

[0059] It should be noted that, in some embodiments, the dual-channel diode can be replaced by two first diodes, such as the anode ends of the two first diodes serve as the two input ends of the dual-channel diode to respectively connect the first voltage-dividing resistor and the second voltage-dividing resistor; and the cathode ends of the two first diodes are connected to serve as the output end of the dual-channel diode.

[0060] In one embodiment, the enable output unit includes a second diode, an anode end of the second diode serves as an input end of the enable output unit and is connected to an output end of the control unit, and a cathode end of the second diode serves as an output end of the enable output unit and is connected to an input end of the DCDC module. Further, when the output end of the control unit provides a high level voltage to the anode end of the second diode, the second diode is turned on, thereby providing an enable signal to the enable end of the DCDC module, so that the DCDC module enters a working state.

[0061] Figure 3 A schematic diagram of the circuit structure of a control unit provided in an embodiment of the present application is shown in FIG. Figure 3 As shown, in one embodiment, the control unit includes a third voltage-dividing resistor R3, a fourth voltage-dividing resistor R4, a fifth voltage-dividing resistor R5, a first filter capacitor C1 and an NPN transistor Q1. A first end of the third voltage-dividing resistor R3 is connected to the output end of the access unit, a second end of the third voltage-dividing resistor R3 is connected to a first end of the first filter capacitor C1, and the first filter capacitor C1 is grounded.

[0062] The third voltage-dividing resistor R3 is also connected to the two ends of the NPN transistor Q1 through the fourth voltage-dividing resistor R4 and the fifth voltage-dividing resistor R5, that is, the second end of the third voltage-dividing resistor R3 is connected to the first end of the fourth voltage-dividing resistor R4, the second end of the fourth voltage-dividing resistor R4 is connected to the base end of the NPN transistor Q1, and the first end of the fourth voltage-dividing resistor R4 serves as the control end of the control unit and is connected to the second end of the switch button; the first end of the third voltage-dividing resistor R3 is connected to the first end of the fifth voltage-dividing resistor R5, the second end of the fifth voltage-dividing resistor R5 is connected to the collector end of the NPN transistor Q1, and the emitter end of the NPN transistor Q1 is grounded.

[0063] The collector terminal of the NPN transistor Q1 serves as the output terminal of the control unit, and the conduction state of the NPN transistor Q1 is controlled by the switch button connected to the first end of the fourth voltage-dividing resistor R4. When the switch button is in the off state, after the third voltage-dividing resistor R3 is connected to the corresponding voltage, after passing through the fourth voltage-dividing resistor R4 and the fifth voltage-dividing resistor R5, the voltage on the base terminal and the collector terminal of the NPN transistor Q1 can meet the conduction condition, and then the NPN transistor Q1 is in the conduction state.

[0064] When the switch button is closed, the first end of the fourth voltage-dividing resistor R4 is grounded, causing the base end of the NPN transistor Q1 to be at a low level voltage, and thus the NPN transistor Q1 does not meet the conduction condition and is in the cut-off state.

[0065] Therefore, the conduction state of the NPN transistor in the control unit is controlled by the switch button, thereby enabling the enable end of the DCDC module, effectively realizing the one-button power on and off function, and the device can completely shut down the battery power after shutting down and before the next startup, thereby effectively protecting the battery power.

[0066] It should be noted that, in some embodiments, the NPN transistor in the control unit can be replaced by an NMOS transistor, so that the voltage at the gate end of the NMOS transistor can be controlled by a switch button to achieve enable control of the DCDC module.

[0067] In one embodiment, the key detection module includes a third diode, the anode end of the third diode serves as the input end of the key detection module, the anode end of the third diode is connected to the second end of the switch key, and the cathode end of the third diode is connected to the signal detection end of the MCU module. It can be understood that when the switch key is in the disconnected state, the anode end of the third diode is connected to a high level, and the third diode is in the on state. Accordingly, the MCU module can determine that the switch key is in the disconnected state according to the high-level voltage signal currently connected to the signal detection end thereon; and when the switch key is in the closed state, the anode end of the third diode is grounded, and the third diode is in the cut-off state. Accordingly, the MCU module can determine that the key detection signal is received according to the low-level voltage signal currently connected to the signal detection end thereon, and then determine that the switch key is in the closed state. Therefore, based on the third diode, the MCU module can quickly determine the state of the switch key, so that when the switch key is in the closed state, the MCU module can timely release the signal latch of the enable end of the DCDC module, which helps to disconnect the power supply in time and save the battery power.

[0068] In one embodiment, a fourth diode is further provided at the signal output end of the MCU module to prevent voltage from flowing back to the signal output end of the MCU module. Specifically, the anode end of the fourth diode is connected to the signal output end of the MCU module, and the cathode end of the fourth diode is connected to the enable end of the DCDC module. It can be understood that due to the unidirectional conduction characteristic of the diode, when the signal output end of the MCU module outputs a high-level latch signal, the fourth diode is in a conducting state, thereby enabling the DCDC module; and a high voltage is connected to the enable end of the DCDC module, and the high voltage is higher than the voltage on the signal output end of the MCU module. Accordingly, the fourth diode is in a cut-off state, thereby avoiding the occurrence of voltage backflow.

[0069] Figure 4 A schematic diagram of the circuit structure of a power-on / off circuit provided in an embodiment of the present application is shown in the figure. As shown in the figure, the output end of the battery module Battery is connected to the circuit through the first voltage-dividing resistor R1, and the 24V voltage connected to the adapter interface is connected to the circuit through the second voltage-dividing resistor R2, that is, the first end of the first voltage-dividing resistor R1 is connected to the output end of the battery module Battery, and the first end of the second voltage-dividing resistor R2 is connected to the adapter interface. In addition, the two input ends of the dual-channel diode D1 are respectively connected to the second end of the first voltage-dividing resistor R1 and the second end of the second voltage-dividing resistor R2.

[0070] The output end of the dual-channel diode D1 is connected to the first end of the third voltage-dividing resistor R3, the second end of the third voltage-dividing resistor R3 is connected to the grounded first filter capacitor C1, and the second end of the third voltage-dividing resistor R3 is also connected to the base end of the NPN transistor Q1 through the fourth voltage-dividing resistor R4, that is, the first end of the fourth voltage-dividing resistor R4 is connected to the second end of the third voltage-dividing resistor R3, and the second end of the fourth voltage-dividing resistor R4 is connected to the base end of the NPN transistor Q1. The first end of the fourth voltage-dividing resistor R4 is also connected to the second end of the switch button K1, and the first end of the switch button K1 is grounded, so that when the switch button K1 is pressed, the fourth voltage-dividing resistor R4 is grounded, thereby changing the conduction state of the NPN transistor Q1.

[0071] In addition, the first end of the third voltage-dividing resistor R3 is also connected to the first end of the fifth voltage-dividing resistor R5, and the second end of the fifth voltage-dividing resistor R5 is connected to the collector end of the NPN transistor Q2, and the emitter end of the NPN transistor Q1 is grounded. In addition, the second end of the fifth voltage-dividing resistor R5 is also connected to the anode end of the second diode D2, and the cathode end of the second diode D2 is connected to the enable pin EN of the DCDC chip U1 in the DCDC module (that is, the enable pin EN serves as the enable end of the DCDC module).

[0072] The MCU chip U2 in the MCU module detects the state of the switch button K1 through the pin GPIO1 thereon, that is, the pin GPIO1 serves as the signal detection end of the MCU module. As shown in the figure, the pin GPIO1 of the MCU chip U2 is connected to the switch button K1 through the third diode D3. Specifically, the pin GPIO1 of the MCU chip U2 is connected to the cathode end of the third diode D3, and the anode end of the third diode D3 is connected to the switch button K1.

[0073] The MCU chip U2 outputs a latch signal to the DCDC chip U1 through the pin GPIO2 thereon, that is, the pin GPIO2 serves as the signal output terminal of the MCU module. As shown in the figure, the pin GPIO2 of the MCU chip U2 is connected to the DCDC chip U1 through the fourth diode D4. Specifically, the pin GPIO2 of the MCU chip U2 is connected to the anode end of the fourth diode D4, and the cathode end of the fourth diode D4 is connected to the enable pin EN of the DCDC chip U1.

[0074] It is understandable that when the device is not turned on, even if the battery module is connected, since the switch button K1 is not pressed, under the action of the third voltage-dividing resistor R3, the fourth voltage-dividing resistor R4 and the fifth voltage-dividing resistor R5, the NPN transistor Q1 meets the conduction condition, and then the NPN transistor Q1 is in the conduction state. Therefore, the anode end of the second diode D2 is connected to a low level, and the second diode D2 is cut off. Correspondingly, the enable pin EN of the DCDC chip in the DCDC module is connected to a low level signal, so that the DCDC module is not in the working state, the device does not start working, and the battery power is preserved.

[0075] In the process of powering on the device, when the switch button K1 is pressed, the switch button K1 is closed so that the NPN transistor Q1 is no longer in the on state, and the anode end of the second diode D2 is connected to a high level, so that the second diode D2 is turned on, thereby enabling the DCDC module, so that the DCDC module enters the working state, and the MCU module is powered on. After powering on, the MCU module works normally, and the MCU chip U2 thereon can output a latch signal to the enable pin EN of the DCDC chip U1 in the DCDC module to keep the device in a normal working state.

[0076] When the device is already powered on, press the switch button K1 again to shut down the device. Specifically, after the switch button K1 is pressed, the anode end of the third diode D3 changes from a high level to a low level, and accordingly, the pin GPIO1 of the MCU chip U1 can detect the state of the third diode D3 to determine that the switch button K1 is pressed. Then the MCU chip U1 stops outputting the latch signal and releases the signal latch of the DCDC chip enable pin EN, thereby realizing the function of completely disconnecting the power supply and effectively saving the battery power.

[0077] It should be conceivable that the resistor shown in the present application scheme may also be composed of multiple resistors connected in series and / or in parallel, so as to meet the requirements for the resistance value.

[0078] The present application also provides a circuit board, which includes a power on / off circuit as provided in the above embodiment. After the circuit board is set in an electronic device, the device can provide a user with a one-button power on / off function through the power on / off circuit on the circuit board, thereby effectively achieving fast startup. At the same time, it can also disconnect the battery power when the device is not turned on, thereby protecting the battery power. There is no need to continuously consume the battery power to achieve fast startup, which helps to avoid the situation where the device needs to be charged before it can be used after being turned on again.

[0079] The present application also provides an electronic device, which includes a circuit board as described above and has the functional effects achieved by the circuit board. The device can respond to the user pressing a switch button to achieve rapid power on and off, and can also shut down the battery power in time, thereby protecting the battery power.

[0080] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0081] Note that the above are only preferred embodiments of the present application and the technical principles used. Those skilled in the art will understand that the present application is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present application. Therefore, although the present application is described in more detail through the above embodiments, the present application is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present application, and the scope of the present application is determined by the scope of the appended claims.

Claims

1. A power on / off circuit, characterized in that: include: A DCDC module, wherein the power supply end of the DCDC module is used to connect the output end of the battery module and the power adapter interface, and to perform voltage conversion on the access voltage in a working state; An MCU module, wherein a power supply end of the MCU module is connected to an output end of the DCDC module, and a signal output end of the MCU module is connected to an enable end of the DCDC module, and the MCU module is used to output a latch signal to the enable end of the DCDC module after power-on or stop outputting the latch signal when receiving a key detection signal; An enabling control module, wherein the first power supply end of the enabling control module is used to connect to the output end of the battery module, the second power supply end of the enabling control module is used to connect to the power adapter interface, the output end of the enabling control module is connected to the enabling end of the DCDC module, and the enabling control module is used to output an enabling signal to the enabling end of the DCDC module through the output end of the enabling control module when a pressing signal is input to the control end of the enabling control module, so as to put the DCDC module in a working state; A switch button, wherein a first end of the switch button is grounded, a second end of the switch button is connected to a control end of the enable control module, and the switch button is used to output the pressing signal to the control end of the enable control module in a closed state; A key detection module, wherein the input end of the key detection module is connected to the second end of the switch key, the output end of the key detection module is connected to the signal detection end of the MCU module, and the key detection module is used to output the key detection signal to the MCU module when the switch key is in a closed state.

2. The switch circuit according to claim 1, characterized in that: The enabling control module includes an access unit, a control unit and an enabling output unit; The first input end of the access unit serves as the first power supply end of the enabling control module, and the second input end of the access unit serves as the second power supply end of the enabling control module; The input end of the control unit is connected to the output end of the access unit, the output end of the control unit is connected to the input end of the enable output unit, and the control end of the control unit serves as the control end of the enable control module and is connected to the second end of the switch button; The output end of the enable output unit serves as the output end of the enable control module and is connected to the enable end of the DCDC module. The enable output unit is used to output the enable signal to the DCDC module when the input end of the enable output unit is connected to a high level voltage.

3. The switch circuit according to claim 2, characterized in that: The access unit includes a first voltage-dividing resistor, a second voltage-dividing resistor and a dual-channel diode; The first end of the first voltage-dividing resistor serves as the first input end of the access unit, and the second end of the first voltage-dividing resistor is connected to the first input end of the dual-channel diode; The first end of the second voltage-dividing resistor serves as the second input end of the access unit, and the second end of the second voltage-dividing resistor is connected to the second input end of the dual-channel diode; The output end of the dual-channel diode serves as the output end of the access unit and is connected to the input end of the control unit. The dual-channel diode is used to output a high-level voltage to the input end of the control unit when a high-level voltage is connected to any input end.

4. The switch circuit according to claim 3, characterized in that: The dual-channel diode is replaced by two first diodes, the anode terminals of the two first diodes serve as an input terminal respectively, and the cathode terminals of the two first diodes are connected to serve as an output terminal.

5. The switch circuit according to claim 2 or 3, characterized in that: The enable output unit includes a second diode; The anode terminal of the second diode serves as the input terminal of the enable output unit and is connected to the output terminal of the control unit; The cathode terminal of the second diode serves as the output terminal of the enable output unit and is connected to the input terminal of the DCDC module.

6. The switch circuit according to claim 2 or 3, characterized in that: The control unit includes a third voltage-dividing resistor, a fourth voltage-dividing resistor, a fifth voltage-dividing resistor, a first filter capacitor and an NPN transistor; The first end of the third voltage-dividing resistor serves as the input end of the control unit and is connected to the output end of the access unit, the second end of the third voltage-dividing resistor is connected to the first end of the first filter capacitor, and the second end of the first filter capacitor is grounded; The first end of the fourth voltage-dividing resistor is connected to the second end of the third voltage-dividing resistor, and the first end of the fourth voltage-dividing resistor serves as the control end of the control unit and is connected to the second end of the switch button, and the second end of the fourth voltage-dividing resistor is connected to the base end of the NPN transistor; The first end of the fifth voltage-dividing resistor is connected to the first end of the third voltage-dividing resistor, the second end of the fifth voltage-dividing resistor is connected to the collector end of the NPN transistor, the collector end of the NPN transistor serves as the output end of the control unit and is connected to the first input end of the enable output unit, and the emitter end of the NPN transistor is grounded.

7. The switch circuit according to claim 1, characterized in that: The button detection module includes a third diode, an anode end of the third diode is connected to the second end of the switch button, and a cathode end of the third diode is connected to the signal detection end of the MCU module.

8. The switch circuit according to claim 1, characterized in that: The signal output end of the MCU module is also provided with a fourth diode, the anode end of the fourth diode is connected to the signal output end of the MCU module, and the cathode end of the fourth diode is connected to the enable end of the DCDC module. The fourth diode is used to prevent voltage from flowing back to the signal output end of the MCU module.

9. A circuit board, characterized in that: The invention comprises a switch circuit as claimed in any one of claims 1 to 8.

10. An electronic device, characterized in that: Comprising the circuit board as claimed in claim 9.

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