Power supply protection device and electronic equipment

Abstract

The utility model provides a power supply protection device and electronic equipment, the power supply protection device comprises a power supply input end, a power supply output end and a control protection circuit arranged between the power supply input end and the power supply output end, the control protection circuit comprises an enabling control switch, a first MOS tube, a second MOS tube and an NPN triode, the drain electrode of the first MOS tube is connected with the power supply input end, and the drain electrode of the second MOS tube is connected with the NPN triode. The drain electrode of the second MOS transistor is connected with the power supply output end, and the emitter electrode of the NPN triode is connected with the enabling control switch. By arranging the control protection circuit, when the enable control switch is converted from high level to low level to close the power output end, the current of the load end flows back to the source electrodes of the first MOS tube and the second MOS tube, and the reversely flowing voltage and current are intercepted through the parasitic diode of the first MOS tube and are prevented from flowing back to the power input end; components in the power supply module are prevented from bearing abnormal voltage and current to affect the service life of the power supply module.

Description

Technical Field

[0001] The utility model relates to the technical field of power supply protection, in particular to a power supply protection device and electronic equipment. Background Art

[0002] Since the power control switch is now disconnected, the voltage and current at the load end will flow back to the input power end. The backflow of voltage and current will cause the components inside the power module to be subjected to abnormal voltage and current, which may cause component failure or damage, reduce stability, and affect the life of the power module. Utility Model Content

[0003] In view of the deficiencies in the prior art, the purpose of the utility model is to provide a power supply protection device and an electronic device, aiming to solve the technical problem in the prior art that, at the moment the power control switch is disconnected, the voltage and current at the load end will flow back to the input power end, and the backflow of voltage and current will cause the components inside the power module to be subjected to abnormal voltage and current, thereby affecting the life of the power module.

[0004] In order to achieve the above-mentioned purpose, the utility model is implemented through the following technical scheme: a power supply protection device, comprising a power supply input end, a power supply output end, and a control protection circuit arranged between the power supply input end and the power supply output end, the control protection circuit comprising an enable control switch, a first MOS tube, a second MOS tube and an NPN transistor, the drain of the first MOS tube is connected to the power supply input end, the drain of the second MOS tube is connected to the power supply output end, the source of the second MOS tube is connected to the source of the first MOS tube, the collector of the NPN transistor is connected to a first resistor, the first resistor comprises a first pin connected to the source of the first MOS tube and the source of the second MOS tube at the same time, and a second pin connected to the gate of the first MOS tube and the gate of the second MOS tube at the same time, the base of the NPN transistor is grounded, and the emitter of the NPN transistor is connected to the enable control switch.

[0005] According to one aspect of the above technical solution, the power protection device further includes a first capacitor and a second capacitor arranged between the power input terminal and the first MOS tube.

[0006] According to one aspect of the above technical solution, the power protection device further includes a third capacitor and a fourth capacitor arranged between the power output terminal and the second MOS tube.

[0007] According to one aspect of the above technical solution, the power protection device also includes an indicator light circuit, which includes a second resistor arranged on one side of the power output end, and a light emitting diode arranged on one side of the second resistor.

[0008] According to one aspect of the above technical solution, the power protection device further includes a third resistor connected to the enable control switch, and one end of the third resistor is connected to the emitter of the NPN transistor.

[0009] According to one aspect of the above technical solution, the power protection device further includes a fourth resistor connected to the base of the NPN transistor.

[0010] Compared with the prior art, the beneficial effect of the utility model lies in that: by setting a control protection circuit, when the enable control switch is changed from a high level to a low level to turn off the power output end, the current at the load end will be fed back to the source of the first MOS tube and the second MOS tube. At this time, the reverse voltage and current will be intercepted by the parasitic diode of the first MOS tube to prevent it from being fed back to the power input end, thereby preventing the components inside the power module from being subjected to abnormal voltage and current, thereby affecting the life of the power module.

[0011] On the other hand, the present application also provides an electronic device, comprising the power protection device described in the above technical solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a circuit structure diagram of a power supply protection device in one embodiment of the utility model;

[0013] Figure 2 A schematic diagram of current flow in a default input state of a power protection device in an embodiment of the utility model;

[0014] Figure 3 A schematic diagram of current flow when the power protection device is in a closed state in one embodiment of the utility model;

[0015] Description of main component symbols:

[0016] Power input terminal 110110, power output terminal 120, first MOS transistor 210, second MOS transistor 220, NPN transistor 230, enable control switch 240, first resistor 310, second resistor 320, light emitting diode 330, third resistor 340, fourth resistor 350, first capacitor 360, second capacitor 370, third capacitor 380, fourth capacitor 390;

[0017] The following specific implementation manner will further illustrate the present utility model in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0018] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. Several embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0019] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the technical field of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0021] See also Figures 1 to 3 , shown is a power protection device in an embodiment of the utility model, including a power input terminal 110, a power output terminal 120, and a control protection circuit arranged between the power input terminal 110 and the power output terminal 120, the control protection circuit includes an enable control switch 240, a first MOS transistor 210, a second MOS transistor 220 and an NPN transistor 230, the drain of the first MOS transistor 210 is connected to the power input terminal 110, the drain of the second MOS transistor 220 is connected to the power output terminal 120, and the second MO The source of the S transistor 220 is connected to the source of the first MOS transistor 210, the collector of the NPN transistor 230 is connected to the first resistor 310, the first resistor 310 includes a first pin connected to the source of the first MOS transistor 210 and the source of the second MOS transistor 220, and a second pin connected to the gate of the first MOS transistor 210 and the gate of the second MOS transistor 220, the base of the NPN transistor 230 is grounded, and the emitter of the NPN transistor 230 is connected to the enable control switch 240.

[0022] like Figure 1 As shown, in some application scenarios of this embodiment, the input "IN_VCC" is the power input terminal 110, and the output is to the "OUT_VCC" power output terminal 120 through the "POWER_EN" enable control switch 240;

[0023] In the default state, the power input terminal 110 is forwardly connected to the first resistor 310 through the first MOS tube 210. Figure 2 As shown by the arrow direction, the gate of the first MOS transistor 210 is set to a high level through the first resistor 310, and the first MOS transistor 210 is turned off;

[0024] When the enable control switch 240 is at a high level, the NPN transistor 230 is grounded, thereby pulling down the gate of the second MOS transistor 220, and the second MOS transistor 220 is turned on, and the circuit VCC flows from the power input terminal 110 to the output terminal;

[0025] When the enable control switch 240 is at a low level, the NPN transistor 230 is turned off, and the gate of the second MOS transistor 220 is at a high level, so the second MOS transistor 220 is turned off.

[0026] When the enable control switch 240 turns from a high level to a low level to turn off the power output terminal 120, the current at the load end will flow back to the source of the first MOS transistor 210 and the second MOS transistor 220. Figure 3 As shown by the arrows, the reverse voltage and current will be intercepted by the parasitic diode of the first MOS tube 210 (the diode has unidirectional conductivity and at this time the diode has a cutoff effect relative to the reverse power supply), so it will not be reversed to the power input terminal 110.

[0027] Preferably, in this embodiment, the power protection device further includes a first capacitor 360 and a second capacitor 370 disposed between the power input terminal 110 and the first MOS transistor 210. The first capacitor 360 and the second capacitor 370 are used to filter and stabilize the power input terminal 110. Further, in this embodiment, the power protection device further includes a third capacitor 380 and a fourth capacitor 390 disposed between the power output terminal 120 and the second MOS transistor 220. By arranging the third capacitor 380 and the fourth capacitor 390 to filter and stabilize the power output terminal 120, the stability of the power supply is ensured.

[0028] In addition, in this embodiment, the power protection device further includes an indicator light circuit, which includes a second resistor 320 disposed on one side of the power output terminal 120, and a light emitting diode 330 disposed on one side of the second resistor 320. When the power is turned on, the indicator light, i.e., the light emitting diode 330, will light up to remind the personnel that the circuit is turned on.

[0029] Preferably, in this embodiment, the power protection device further comprises a third resistor 340 connected to the enable control switch 240, and one end of the third resistor 340 is connected to the emitter of the NPN transistor 230. In some application scenarios of this embodiment, since the enable control switch 240 is generally an IO port signal of a single-chip microcomputer, the third resistor 340 is provided to isolate the influence of the subsequent circuit on the enable control switch 240, thereby protecting the IO port of the single-chip microcomputer.

[0030] Preferably, in this embodiment, the power protection device further comprises a fourth resistor 350 connected to the base of the NPN transistor 230. The fourth resistor 350 is a zero-level resistor of the NPN transistor 230 to ensure that the NPN transistor 230 is in a closed state by default, to prevent the base level of the transistor from being affected instantly when the circuit starts, resulting in unstable output of the subsequent circuit and damage to the load device.

[0031] In summary, the power protection device in the above-mentioned embodiment of the utility model is provided with a control protection circuit. When the enable control switch 240 is changed from a high level to a low level to turn off the power output terminal 120, the current at the load end will be fed back to the source of the first MOS tube 210 and the second MOS tube 220. At this time, the back-fed voltage and current will be intercepted by the parasitic diode of the first MOS tube 210 to prevent it from being fed back to the power input terminal 110, thereby preventing the components inside the power module from being subjected to abnormal voltage and current, thereby affecting the life of the power module and protecting the front-stage power supply.

[0032] A second embodiment of the present application provides an electronic device, comprising the power protection device in the above embodiment.

[0033] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0034] The above-mentioned embodiments only express several implementation methods of the utility model, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the utility model. It should be pointed out that, for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, and these all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model shall be subject to the attached claims.

Claims

1. A power supply protection device, characterized in that: The invention comprises a power input terminal, a power output terminal, and a control protection circuit arranged between the power input terminal and the power output terminal, wherein the control protection circuit comprises an enable control switch, a first MOS tube, a second MOS tube, and an NPN transistor, wherein the drain of the first MOS tube is connected to the power input terminal, the drain of the second MOS tube is connected to the power output terminal, the source of the second MOS tube is connected to the source of the first MOS tube, the collector of the NPN transistor is connected to a first resistor, the first resistor comprises a first pin connected to the source of the first MOS tube and the source of the second MOS tube at the same time, and a second pin connected to the gate of the first MOS tube and the gate of the second MOS tube at the same time, the base of the NPN transistor is grounded, and the emitter of the NPN transistor is connected to the enable control switch.

2. The power protection device according to claim 1, characterized in that: The power protection device also includes a first capacitor and a second capacitor which are arranged between the power input terminal and the first MOS tube.

3. The power protection device according to claim 1, characterized in that: The power protection device also includes a third capacitor and a fourth capacitor which are arranged between the power output terminal and the second MOS tube.

4. The power protection device according to claim 1, characterized in that: The power protection device further comprises an indicator light circuit, wherein the indicator light circuit comprises a second resistor arranged at one side of the power output end, and a light emitting diode arranged at one side of the second resistor.

5. The power protection device according to claim 4, characterized in that: The power protection device further includes a third resistor connected to the enable control switch, and one end of the third resistor is connected to the emitter of the NPN transistor.

6. The power protection device according to claim 1, characterized in that: The power protection device further includes a fourth resistor connected to the base of the NPN transistor.

7. An electronic device, characterized in that: The invention comprises the power supply protection device as described in any one of claims 1 to 6.

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