Power failure protection circuit and startup and shutdown circuit

Abstract

The embodiment of the utility model discloses a power failure protection circuit and a startup and shutdown circuit. The power failure protection circuit comprises an input control module, a protection state switching module and a discharge module, the input control module is connected with the protection state switching module, the protection state switching module is connected with the discharge module, and the protection state switching module is connected with the load; the input control module can control the protection state switching module to conduct a conduction loop between the load and the discharge module when the protection state switching module is started, and control the protection state switching module to conduct a conduction loop between the load and the input control module when the protection state switching module is closed. And the discharging module can release the electric energy stored by the load. According to the scheme, electric quantity stored in the load can be prevented from flowing backwards, and the power-down speed of the load is increased.

Description

Technical Field

[0001] The embodiments of the utility model relate to the technical field of electronic circuits, and in particular to a power-off protection circuit and a power-on / off circuit. Background Art

[0002] Currently, after a normal shutdown, circuits can experience backflow of current and slow voltage drop. This backflow can cause some components to continue operating or become damaged after the circuit shuts down, leading to abnormal shutdown. Furthermore, restarting the circuit while some components are powered off can cause abnormal startup, damaging backend components and preventing them from functioning properly. Utility Model Content

[0003] The embodiments of the present invention provide a power-off protection circuit and a power-on / off circuit to prevent current backflow and increase the power-off speed.

[0004] In a first aspect, an embodiment of the present utility model provides a power-off protection circuit, which includes: an input control module, a protection state switching module, and a discharge module;

[0005] The input control module is connected to the protection state switching module, the protection state switching module is connected to the discharge module, and the protection state switching module is connected to the load;

[0006] The input control module includes a power input control terminal and a power supply control terminal;

[0007] The protection state switching module includes a power supply switch and a power-off protection switch;

[0008] The power input control terminal and the first pole of the power supply switch are both connected to the control terminal of the power-off protection switch, the second pole of the power supply switch and the first stage of the power-off protection switch are both connected to the load, the second pole of the power-off protection switch is connected to the discharge module, and the power supply control terminal is connected to the control terminal of the power supply switch.

[0009] Optionally, the power supply switch includes a PMOS tube; the power-off protection switch includes a transistor;

[0010] The source of the Pmos transistor serves as the first electrode of the power switch, the gate of the Pmos transistor serves as the control terminal of the power switch, and the drain of the Pmos transistor serves as the second electrode of the power switch;

[0011] The base of the transistor serves as the control end of the power-off protection switch, the emitter of the transistor serves as the first electrode of the power-off protection switch, and the collector of the transistor serves as the second electrode of the power-off protection switch.

[0012] Optionally, the discharge module includes a first resistor;

[0013] A first end of the first resistor is connected to the protection state switching module, and a second end of the first resistor is grounded.

[0014] Optionally, the power-off protection circuit further includes an indication module;

[0015] A first end of the indication module is connected to the protection state switching module and the load, a second end of the indication module is grounded with the discharge module, and the indication module can indicate the operating state of the load.

[0016] Optionally, the indication module includes a current limiting unit and an indication unit;

[0017] A first end of the current limiting unit is connected to the protection state switching module and the load, a second end of the current limiting unit is connected to a first end of the indicating unit, and a second end of the indicating unit is grounded to the discharge module.

[0018] Optionally, the current limiting unit includes a second resistor, and the indicating unit includes a light emitting diode;

[0019] The first end of the second resistor serves as the first end of the current limiting unit, and the second end of the second resistor serves as the second end of the current limiting unit;

[0020] The anode of the light emitting diode serves as the first end of the indicator unit, and the cathode of the light emitting diode serves as the second end of the indicator unit.

[0021] Optionally, the power-off protection circuit further includes a pull-down module;

[0022] The first end of the pull-down module is connected to the input control module and the protection state switching module, and the second end of the pull-down module shares a common ground with the discharge module.

[0023] Optionally, the pull-down module includes a third resistor;

[0024] The first end of the third resistor serves as the first end of the pull-down module, and the second end of the third resistor serves as the second end of the pull-down module.

[0025] In a second aspect, an embodiment of the present invention further provides a power on / off circuit, which includes the power-off protection circuit provided by any embodiment of the present invention.

[0026] In this embodiment of the utility model, when the power supply control terminal controls the power switch to conduct, the power switch can control the power output from the power input control terminal to provide power to the load. When the power input control terminal stops providing power to the load and the power supply control terminal controls the power switch to shut down, the power failure protection switch can control the load to conduct with the discharge module, thereby releasing the power stored in the load through the discharge module, preventing the power stored in the load from flowing back into the input control module, and improving the power failure speed of the load. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 A schematic structural diagram of a power-off protection circuit provided in an embodiment of the present utility model;

[0029] Figure 2 A schematic structural diagram of another power-off protection circuit provided in an embodiment of the present utility model;

[0030] Figure 3 A schematic structural diagram of another power-off protection circuit provided in an embodiment of the present utility model;

[0031] Figure 4 A schematic structural diagram of another power-off protection circuit provided in an embodiment of the present utility model;

[0032] Figure 5 A schematic structural diagram of another power-off protection circuit provided in an embodiment of the present utility model;

[0033] Figure 6 A schematic structural diagram of another power-off protection circuit provided in an embodiment of the present utility model;

[0034] Figure 7 A schematic structural diagram of another power-off protection circuit provided in an embodiment of the present utility model;

[0035] Figure 8 A schematic structural diagram of another power-off protection circuit provided in an embodiment of the present utility model;

[0036] Figure 9 This is a structural diagram of another power-off protection circuit provided by an embodiment of the present utility model. DETAILED DESCRIPTION

[0037] In order to help those skilled in the art better understand the present invention, the following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0038] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0039] Figure 1 A schematic diagram of a power-off protection circuit according to an embodiment of the present invention is shown in FIG. Figure 1 As shown, the power-off protection circuit includes: an input control module 110, a protection state switching module 120 and a discharge module 130;

[0040] The input control module 110 is connected to the protection state switching module 120 , the protection state switching module 120 is connected to the discharge module 130 , and the protection state switching module 120 is connected to the load 210 ;

[0041] The input control module 110 can control the conduction loop between the load 210 and the discharge module 130 when the protection state switching module 120 is started, and control the conduction loop between the load 210 and the input control module 110 when the protection state switching module 120 is turned off; the discharge module 130 can release the electrical energy stored in the load 210.

[0042] The input control module 110 can control the protection state switching module 120 to start or stop, so that the protection state switching module 120 conducts different circuits when it is started and shut down. Under the control of the input control module 110, the protection state switching module 120 can select the circuit between the load 210 and the input control module 110 or the protection state switching module 120 to conduct. This allows the input control module 110 to output electrical energy to the load 210 when the circuit is in the power-on state, and the discharge module 130 to promptly release the electrical energy stored in the load 210 when the circuit is in the power-off state. (The load 210 refers to a power-consuming device. Because power-consuming devices are equipped with devices with energy storage characteristics, such as inductors and capacitors, some electrical energy of the load 210 will be stored in the capacitors and inductors after power is lost.)

[0043] When the input control module 110 controls the protection state switching module 120 to be off, the protection state switching module 120 will connect the circuit between the load 210 and the input control module 110, so that the input control module 110 supplies power to the load 210. When the input control module 110 controls the protection state switching module 120 to be on, the protection state switching module 120 will connect the circuit between the load 210 and the discharge module 130, so that the power stored in the load 210 is released through the discharge module 130, preventing the power stored in the load 210 from flowing back into the input control module 110, thereby increasing the power-off speed of the load 210.

[0044] Specifically, Figure 2 A schematic diagram of another power-off protection circuit provided by an embodiment of the present invention is shown in FIG. Figure 2 As shown, the input control module 110 includes a power input control terminal 111 and a power supply control terminal 112;

[0045] The protection state switching module 120 includes a power switch 121 and a power-off protection switch 122;

[0046] The power input control terminal 111 and the first pole of the power supply switch 121 are both connected to the control terminal of the power failure protection switch 122, the second pole of the power supply switch 121 and the first stage of the power failure protection switch 122 are both connected to the load 210, the second pole of the power failure protection switch 122 is connected to the discharge module 130, and the power supply control terminal 112 is connected to the control terminal of the power supply switch 121.

[0047] The power supply control terminal 112 can control the conduction state of the power supply switch 121. When the power supply control terminal 112 controls the power supply switch 121 to be turned on, the power supply switch 121 can control the power output from the power input control terminal 111 to provide power to the load 210. When the power input control terminal 111 stops providing power to the load 210 and the power supply control terminal 112 controls the power supply switch 121 to be turned off, the power failure protection switch 122 can control the load 210 to be connected to the discharge module 130, so that the power stored in the load 210 is released through the discharge module 130, preventing the power stored in the load 210 from flowing back into the input control module 110, thereby increasing the power failure speed of the load 210.

[0048] Based on the above embodiment, optionally, Figure 3 This is a schematic diagram of another power-off protection circuit provided by an embodiment of the present utility model. Figure 3 As shown, the power switch 121 includes a PMOS transistor P; the power-off protection switch 122 includes a transistor Q;

[0049] The source of the Pmos transistor P serves as the first electrode of the power supply switch 121, the gate of the Pmos transistor P serves as the control end of the power supply switch 121, and the drain of the Pmos transistor P serves as the second electrode of the power supply switch 121; the base of the transistor Q serves as the control end of the power-off protection switch 122, the emitter of the transistor Q serves as the first electrode of the power-off protection switch 122, and the collector of the transistor Q serves as the second electrode of the power-off protection switch 122.

[0050] Specifically, the source of the Pmos transistor P and the base of the transistor Q are both connected to the power input control terminal 111, the gate of the Pmos transistor P is connected to the power supply control terminal 112, the drain of the Pmos transistor P is connected to the emitter of the transistor Q, and the collector of the transistor Q is connected to the discharge module 130.

[0051] When the power supply control terminal 112 outputs a low voltage and the power input control terminal 111 outputs a power voltage, the PMOS transistor P is turned on and the transistor Q is turned off. At this time, the power input control terminal 111 provides power to the load 210. When the power supply control terminal 112 outputs a high voltage and the power input control terminal 111 stops outputting a power voltage, the PMOS transistor P is turned off and the transistor Q is turned on. At this time, the load 210 is connected to the discharge module 130, so that the power stored in the load 210 is released through the discharge module 130, preventing the power stored in the load 210 from flowing back into the input control module 110, thereby improving the power-off speed of the load 210.

[0052] Based on the above embodiment, optionally, Figure 4 This is a schematic diagram of another power-off protection circuit provided by an embodiment of the present utility model. Figure 4As shown, the discharge module 130 includes a first resistor R1 ; a first end of the first resistor R1 is connected to the protection state switching module 120 , and a second end of the first resistor R1 is grounded.

[0053] Specifically, a first end of the first resistor R1 is connected to the collector of the transistor Q. When the first resistor R1 is connected to the load 210 , it can consume the electric energy stored in the load 210 .

[0054] Based on the above embodiment, optionally, Figure 5 This is a schematic diagram of another power-off protection circuit provided by an embodiment of the present utility model. Figure 5 The power-off protection circuit shown further includes an indication module 140;

[0055] A first end of the indication module 140 is connected to the protection state switching module 120 and the load 210 , and a second end of the indication module 140 is grounded to the discharge module 130 . The indication module 140 can indicate the operating state of the load 210 .

[0056] Based on the above embodiment, optionally, Figure 6 This is a schematic diagram of another power-off protection circuit provided by an embodiment of the present utility model. Figure 6 As shown, the indication module 140 includes a current limiting unit 141 and an indication unit 142;

[0057] A first end of the current limiting unit 141 is connected to the protection state switching module 120 and the load 210 , a second end of the current limiting unit 141 is connected to a first end of the indicating unit 142 , and a second end of the indicating unit 142 is grounded to the discharge module 130 .

[0058] The current limiting unit 141 can limit the current flowing through the indicator unit 142 to prevent the indicator unit 142 from burning out due to excessive current. The indicator unit 142 can indicate the power supply status of the load 210 when the circuit is powered on, and can indicate the discharge status of the stored energy in the load 210 when the circuit is powered off. In addition, when the circuit is powered off, the current limiting unit 141 can also release the stored energy in the load 210, further improving the power-off speed of the load 210.

[0059] Based on the above embodiment, optionally, Figure 7 This is a schematic diagram of another power-off protection circuit provided by an embodiment of the present utility model. Figure 7 As shown, the current limiting unit 141 includes a second resistor R2, and the indicating unit 142 includes a light emitting diode D;

[0060] The first end of the second resistor R2 serves as the first end of the current limiting unit 141, and the second end of the second resistor R2 serves as the second end of the current limiting unit 141; the anode of the light-emitting diode D serves as the first end of the indicating unit 142, and the cathode of the light-emitting diode D serves as the second end of the indicating unit 142.

[0061] Specifically, the first end of the second resistor R2 is connected to the drain of the PMOS tube P and the load 210, the first end of the second resistor R2 is connected to the anode of the light-emitting diode D, and the cathode of the light-emitting diode D is grounded with the second end of the first resistor R1.

[0062] For example, when the circuit is powered on, if LED D is illuminated, it indicates that the load 210 is receiving normal power. If LED D is not illuminated, it indicates that the load 210 is receiving abnormal power. When the circuit is powered off, if LED D is illuminated, it indicates that the load 210 is discharging power. If LED D is not illuminated, it indicates that the load 210 has completed discharging power.

[0063] Based on the above embodiment, optionally, Figure 8 This is a schematic diagram of another power-off protection circuit provided by an embodiment of the present utility model. Figure 8 As shown, the power-off protection circuit further includes a pull-down module 150;

[0064] The first end of the pull-down module 150 is connected to the input control module 110 and the protection state switching module 120 , and the second end of the pull-down module 150 is grounded to the discharge module 130 .

[0065] Specifically, a first end of the pull-down module 150 is connected to the source of the PMOS transistor P, the power input control terminal 111 and the base of the transistor Q, and a second end of the pull-down module 150 is grounded to the second end of the first resistor R1 .

[0066] The pull-down module 150 can pull down the potential of the base of the transistor Q when the power input control terminal 111 stops outputting the power voltage.

[0067] Based on the above embodiment, optionally, Figure 9 This is a schematic diagram of another power-off protection circuit provided by an embodiment of the present utility model. Figure 9 As shown, the pull-down module 150 includes a third resistor R3 ; a first end of the third resistor R3 serves as a first end of the pull-down module 150 , and a second end of the third resistor R3 serves as a second end of the pull-down module 150 .

[0068] Specifically, a first end of the third resistor R3 is connected to the source of the PMOS transistor P, the power input control terminal 111 and the base of the transistor Q, and a second end of the third resistor R3 is grounded to the second end of the first resistor R1.

[0069] An embodiment of the present invention further provides a power on / off circuit, which includes the power-off protection circuit provided by any embodiment of the present invention.

[0070] Among them, the power on / off circuit refers to a circuit that controls the startup and shutdown of a device or component (load). The power on / off circuit is added with the power-off protection circuit provided by the present invention. When the device or component is started up, the power energy output from the power input control terminal can be controlled to provide power to the device or component, and when the device or component is shut down, the power stored in the load is released to prevent the power stored in the load 210 from being fed back into the input control module, thereby increasing the power off speed of the load.

[0071] Therefore, the power on / off circuit provided by the embodiment of the present invention includes the beneficial effects of the power off protection circuit provided by any embodiment of the present invention, which will not be repeated here.

[0072] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in this utility model can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of this utility model can be achieved. This is not limited herein.

[0073] The above specific embodiments do not limit the scope of protection of this utility model. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model shall be included within the scope of protection of this utility model.

Claims

1. A power-off protection circuit, characterized in that: include: Input control module, protection state switching module and discharge module; The input control module is connected to the protection state switching module, the protection state switching module is connected to the discharge module, and the protection state switching module is connected to the load; The input control module includes a power input control terminal and a power supply control terminal; The protection state switching module includes a power supply switch and a power-off protection switch; The power input control terminal and the first pole of the power supply switch are both connected to the control terminal of the power-off protection switch, the second pole of the power supply switch and the first stage of the power-off protection switch are both connected to the load, the second pole of the power-off protection switch is connected to the discharge module, and the power supply control terminal is connected to the control terminal of the power supply switch.

2. The power-off protection circuit according to claim 1, characterized in that: The power supply switch includes a PMOS tube; the power-off protection switch includes a transistor; The source of the Pmos transistor serves as the first electrode of the power switch, the gate of the Pmos transistor serves as the control terminal of the power switch, and the drain of the Pmos transistor serves as the second electrode of the power switch; The base of the transistor serves as the control end of the power-off protection switch, the emitter of the transistor serves as the first electrode of the power-off protection switch, and the collector of the transistor serves as the second electrode of the power-off protection switch.

3. The power-off protection circuit according to claim 1, wherein: The discharge module includes a first resistor; A first end of the first resistor is connected to the protection state switching module, and a second end of the first resistor is grounded.

4. The power-off protection circuit according to claim 1, wherein: Also included is an indication module; A first end of the indication module is connected to the protection state switching module and the load, a second end of the indication module is grounded with the discharge module, and the indication module can indicate the operating state of the load.

5. The power-off protection circuit according to claim 4, characterized in that: The indication module includes a current limiting unit and an indication unit; A first end of the current limiting unit is connected to the protection state switching module and the load, a second end of the current limiting unit is connected to a first end of the indicating unit, and a second end of the indicating unit is grounded to the discharge module.

6. The power-off protection circuit according to claim 5, characterized in that: The current limiting unit includes a second resistor, and the indicating unit includes a light emitting diode; The first end of the second resistor serves as the first end of the current limiting unit, and the second end of the second resistor serves as the second end of the current limiting unit; The anode of the light emitting diode serves as the first end of the indicator unit, and the cathode of the light emitting diode serves as the second end of the indicator unit.

7. The power-off protection circuit according to claim 1, wherein: Also includes drop-down modules; The first end of the pull-down module is connected to the input control module and the protection state switching module, and the second end of the pull-down module shares a common ground with the discharge module.

8. The power-off protection circuit according to claim 7, characterized in that: The pull-down module includes a third resistor; The first end of the third resistor serves as the first end of the pull-down module, and the second end of the third resistor serves as the second end of the pull-down module.

9. A power on / off circuit, characterized in that: The invention comprises the power-off protection circuit according to any one of claims 1 to 8.

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