Protection circuit and electronic equipment

Abstract

The utility model relates to the field of electronic equipment, and provides a protection circuit and electronic equipment, the protection circuit is used for providing surge protection for energy storage equipment, and the protection circuit is characterized by comprising a signal input port, a surge suppression unit, a circuit protection unit, a charging management unit and a signal output port; when an input signal of the signal input port is smaller than a first preset value, the circuit protection unit disconnects a connection path between the signal input port and the energy storage equipment; when an input signal of the signal input port is greater than or equal to a first preset value and less than a second preset value, a connection path between the signal input port and the energy storage equipment is conducted; and when the input signal of the signal input port is greater than a second preset value, the signal input port is grounded by the surge suppression unit.

Description

Technical Field

[0001] The present application relates to the field of electronic equipment, and in particular to a protection circuit and electronic equipment. Background Art

[0002] Surges, also known as power surges or transients, are brief, sharp increases in voltage or current that typically occur in power systems. Surges can be caused by lightning strikes, the sudden closing of a power switch, and other factors. To prevent surges from causing the voltage or current of electronic devices to exceed their normal operating range and damage the equipment, surge protectors (SPDs) are often added to electronic devices to absorb or limit the surge's energy. However, even after being absorbed by a surge protector, negative surges can still cause the voltage of the electronic device to drop. Therefore, there is an urgent need for a circuit that can protect electronic devices from negative surges. Summary of the Invention

[0003] The main purpose of this application is to provide a protection circuit and electronic equipment, aiming to prevent electronic equipment from being affected by negative surges and improve the user experience.

[0004] In a first aspect, the present application provides a protection circuit for at least providing surge protection for an energy storage device, the protection circuit comprising: a signal input port, a surge suppression unit, a circuit protection unit, a charging management unit, and a signal input port;

[0005] A first end of the surge suppression unit is connected to the signal input port, and a second end of the surge suppression unit is grounded;

[0006] The first end of the circuit protection unit is connected to the signal input port, the second end of the circuit protection unit is connected to the input end of the charging management unit, the first output end of the charging management unit is connected to the energy storage device, and the second output end of the charging management unit is connected to the signal output port, and the signal output port is used to connect to a load;

[0007] When the input signal of the signal input port is less than a first preset value, the circuit protection unit disconnects the connection path between the signal input port and the energy storage device;

[0008] When the input signal of the signal input port is greater than or equal to the first preset value and less than a second preset value, the connection path between the signal input port and the energy storage device is connected;

[0009] When the input signal of the signal input port is greater than the second preset value, the surge suppression unit grounds the signal input port.

[0010] In a second aspect, the present application further provides an electronic device, comprising a protection circuit, an energy storage device, and a load as described in any one of the embodiments of the present application, wherein the protection circuit is connected to the energy storage device and the load, respectively.

[0011] The protection circuit and electronic device provided in the embodiments of the present application can prevent the current backflow phenomenon in the energy storage device when the input signal is too low, so that the energy storage device can continuously supply power to the load, thereby preventing the load from resetting due to insufficient voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0013] Figure 1 A circuit diagram of an electronic product provided in an embodiment of the present application;

[0014] Figure 2 A voltage-time relationship diagram of points A and B under a forward surge voltage input according to an embodiment of the present application;

[0015] Figure 3 A voltage-time relationship diagram of points A and B under a negative input surge voltage according to an embodiment of the present application;

[0016] Figure 4 Provided for an embodiment of this application Figure 1 Equivalent circuit diagram of

[0017] Figure 5 A schematic diagram of the structure of a protection circuit provided in one embodiment of the present application;

[0018] Figure 6 A schematic structural diagram of a circuit protection unit 103 provided in one embodiment of the present application;

[0019] Figure 7 A circuit diagram of a unidirectional protection unit provided in one embodiment of the present application;

[0020] Figure 8 A circuit diagram of an electronic device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0022] The flowcharts shown in the accompanying drawings are for illustrative purposes only and do not necessarily include all contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps may be decomposed, combined, or partially merged, so the actual execution order may vary depending on the actual situation.

[0023] The embodiments of the present application provide a protection circuit and an electronic device. Some implementation methods of the present application are described in detail below with reference to the accompanying drawings. The following embodiments and features of the embodiments can be combined with each other unless there is a conflict.

[0024] See Figure 1 , Figure 1 A circuit diagram of an electronic product provided in an embodiment of the present application.

[0025] like Figure 1 As shown, the electronic product provided in the embodiment of the present application is powered by a battery, such as a smartphone, tablet computer, laptop computer, etc. When charging by connecting to an external power port, that is, when point A is connected to the external power port, the battery is connected to the external power port. To prevent the impact of surges on electronic devices, a surge suppression unit, such as a surge tube, is provided in the electronic device.

[0026] Please refer to Figure 2 、 Figure 3 , Figure 2 A voltage-time relationship diagram of points A and B under a forward surge voltage input according to an embodiment of the present application; Figure 2 This is a voltage-time relationship diagram of points A and B under the condition of inputting a negative surge voltage provided by an embodiment of the present application.

[0027] like Figure 2 、 Figure 3 As shown in the figure, once the surge signal is input through the external power port, the surge tube of the power port can clamp the voltage of the subsequent circuit at a lower level. Therefore, even if a surge signal exceeding the normal operating voltage is input at point A, the voltage at point B can maintain a small fluctuation range.

[0028] However, in the event of a negative input surge, the voltage at point B is instantly pulled down to -Vf. Due to the short surge discharge time, the overvoltage protector and charging IC in the electronic device cannot shut down in time. The voltage drop at point A causes the voltage drops at points B and C, which in turn causes the interface voltage Vsys of the charging IC connected to the battery to drop. The battery current flows in reverse to the charging IC, points C, and B. When the battery's discharge capacity is insufficient, the voltage supplied to the load by the battery will be less than the minimum operating voltage VLmin of the electronic device, causing the electronic device system to reset and affecting the user experience.

[0029] See Figure 4 , Figure 4 Provided for an embodiment of this application Figure 1 The equivalent circuit of .

[0030] Among them, R g The equivalent resistance of the fuel gauge is the sum of the on-resistance, the current sampling resistor, and the DC impedance of the battery-fuel gauge-charging IC circuit; R ovp / ocp The equivalent resistance is the sum of the internal resistance of the overcurrent protection device and / or overvoltage protection device plus the DC impedance of the line from the overcurrent protection device and / or overvoltage protection device to the charging IC; R DS1 Indicates the V of the charging IC bus With V sys The DC internal resistance, R DS2 Indicates the V of the charging IC bus to V sys The DC internal resistance, R L Indicates the DC resistance of the load; I Vbat Indicates the current output from the battery when a negative voltage surge occurs at point A; I S Indicates that when a negative voltage surge occurs at point A, the V BUS The reverse current discharged at point C; I L Indicates the load current.

[0031] like Figure 4 As shown in the figure, when a negative voltage surge signal is input to point A, if the discharged reverse current I S Larger, will cause the flow to the load I L If the voltage supplied by the battery to the load is lower than the minimum operating voltage VLmin of the electronic device, the load system will be reset, affecting user experience.

[0032] To avoid this situation, an embodiment of the present application provides a protection circuit 10 for at least providing surge protection for an energy storage device 20. The protection circuit 10 includes: a signal input port 101, a surge suppression unit 102, a circuit protection unit 103, a charging management unit 104, and a signal output port 105.

[0033] A first end of the surge suppression unit 102 is connected to the signal input port 101 , and a second end of the surge suppression unit 102 is grounded;

[0034] A first end of the circuit protection unit 103 is connected to the signal input port 101 , a second end of the circuit protection unit 103 is connected to the input end of the charging management unit 104 , a first output end of the charging management unit 104 is connected to the energy storage device 20 , and a second output end of the charging management unit 104 is connected to the signal output port 105 , which is used to connect to the load 30 ;

[0035] When the input signal of the signal input port 101 is less than the first preset value, the circuit protection unit 103 disconnects the connection path between the signal input port 101 and the energy storage device 20;

[0036] When the input signal of the signal input port 101 is greater than or equal to the first preset value and less than the second preset value, the connection path between the signal input port 101 and the energy storage device 20 is connected;

[0037] When the input signal of the signal input port 101 is greater than a second preset value, the surge suppression unit 102 grounds the signal input port 105 .

[0038] Specifically, the signal input port 101 is used to connect to an external power source to charge the energy storage device 20 of the electronic device. In situations such as when the external power source starts and stops, or during lightning, a surge signal may be generated. The surge suppression unit 102 is used to limit transient overvoltages and discharge corresponding transient overcurrents to protect the electronic device from surge damage. The surge suppression unit is cut off under normal circumstances and quickly turns on when the voltage exceeds a safety threshold, discharging the overvoltage energy to the ground line, thereby protecting the device.

[0039] The circuit protection unit is used to cut off when the input signal of the signal input port 101 is less than a first preset value, and to turn on when the input signal is greater than or equal to the first preset value, so as to prevent the negative surge from discharging the voltage of the energy storage device 20 and causing the voltage of the load 30 to drop. This ensures that in the event of a negative surge, the energy storage device 20 can normally supply power to the load 30, maintain the operation of the load 30, and improve the user experience.

[0040] See Figure 6 , Figure 6 This is a structural diagram of the circuit protection unit 103 provided in one embodiment of the present application.

[0041] like Figure 6As shown, in some embodiments, the circuit protection unit 103 includes a unidirectional protection unit 1031, a first end of the unidirectional protection unit 1031 is connected to the signal input port 101, and a second end of the unidirectional protection unit 1031 is connected to the input end of the charging management unit 104; the unidirectional protection unit 1031 is cut off when the input signal of the signal input port 101 is less than a first preset value, so as to disconnect the connection path between the signal input port 101 and the energy storage device 20; the unidirectional protection unit 1031 is turned on when the input signal of the signal input port 101 is greater than or equal to the first preset value, so as to connect the connection path between the signal input port 101 and the energy storage device 20.

[0042] For example, the input signal may be an input voltage, and the first preset value may be 0. That is, the unidirectional protection unit 1031 is turned on when the input voltage is positive and turned off when the input voltage is negative. This disconnects the path between the energy storage device 20 and the signal input port 101 in the event of a negative input surge, preventing the signal input port 101 from discharging the voltage of the energy storage device 20 at the moment of a negative input surge. Of course, this is not limiting, and the first preset value may also be other values, which are not limited here.

[0043] In some embodiments, the unidirectional protection unit 1031 includes a first switching transistor and a second switching transistor, wherein a first end of the first switching transistor is connected to the signal input port 101, a second end of the first switching transistor is connected to the input end of the charging management unit 104, a control end of the first switching transistor is connected to the second end of the second switching transistor, a control end of the second switching transistor is connected to the signal input port, and a first end of the second switching transistor is grounded;

[0044] When the input signal of the signal input port 101 is less than the first preset value, the first switch tube and the second switch tube are turned off. When the input signal of the signal input port 101 is greater than or equal to the first preset value, the first switch tube and the second switch tube are turned on.

[0045] Exemplarily, the first switch tube and the second switch tube may be field effect transistors (MOS tubes for short) or bipolar junction transistors (BJTs for short), which are not limited here.

[0046] Please refer to Figure 7 , Figure 7 A circuit diagram of a unidirectional protection unit provided in one embodiment of the present application.

[0047] like Figure 7As shown, the first switching transistor is a PMOS, and the second switching transistor is an NMOS. The gate of the NMOS and the drain of the PMOS are connected to the signal input port 101, the drain of the NMOS is connected to the gate of the PMOS, the source of the NMOS is grounded, and the source of the PMOS is connected to the charge management unit 104 of the subsequent circuit. When a positive surge is input to point B, both the NMOS and the PMOS are turned on, the unidirectional protection unit conducts normally, and the surge signal is clamped to a safe voltage by the surge suppression unit 102, protecting the subsequent circuit. When a negative voltage surge is input to point B, since the Vgs of the NMOS is less than 0V, the NMOS is turned off, and the PMOS is therefore turned off, isolating it from the subsequent circuit, thereby protecting the subsequent circuit from voltage drops.

[0048] In some embodiments, the unidirectional protection unit includes a diode, an anode of the diode is connected to the signal input port, and a cathode of the diode is connected to the input terminal of the charging management unit.

[0049] For example, the unidirectional protection circuit 1031 provided in the embodiment of the present application is not limited to Figure 7 For example, in an application scenario where the voltage drop requirement for the subsequent circuit is not high, a diode with low on-resistance can be used as the unidirectional protection unit 1031, so that the diode is cut off when the input signal of the signal input port 101 is less than the first preset value, and is turned on when the input signal is greater than the first preset value, thereby achieving unidirectional protection and preventing negative surges.

[0050] Please continue to refer to Figure 6 ,like Figure 6 As shown, in some embodiments, the circuit protection unit 103 further includes an overvoltage protection unit 1032, the input end of the overvoltage protection unit 1032 is connected to the second end of the unidirectional protection unit 1031, and the output end of the overvoltage protection unit 1032 is connected to the input end of the charging management unit 104, for providing overvoltage protection for the energy storage device 20;

[0051] And / or, the circuit protection unit 103 also includes an overcurrent protection unit 1033, the input end of the overcurrent protection unit 1033 is connected to the second end of the unidirectional protection unit 1031, and the output end of the overcurrent protection unit 1033 is connected to the input end of the charging management unit 104, for providing overcurrent protection for the energy storage device 20.

[0052] Specifically, an overvoltage protection unit is typically connected in parallel with the circuit being protected. When the input voltage does not exceed the set value, the overvoltage protection element assumes a high-impedance state, barely affecting the normal operation of the circuit. Once the voltage exceeds the set value, the overvoltage protection element quickly turns on, clamping the excessive voltage and protecting subsequent circuits from damage. An overcurrent protection unit, on the other hand, is typically connected in series with the circuit. The overcurrent protection element monitors the current flowing through it and, when the current exceeds the set value, shuts off the circuit to prevent damage to the equipment caused by the overcurrent.

[0053] In some embodiments, the charging management unit 104 includes a charging IC, a first output terminal of the charging IC is connected to the energy storage device 20 , and a second output terminal of the charging IC is connected to the signal output port 105 .

[0054] For example, a charging IC is an electronic component specifically used to manage and control the current and voltage during the charging process. It can monitor and control the charging current and voltage, prevent abnormalities in the charger or charging line, protect the charger and mobile devices from overcharging, over-discharging, overheating, etc., optimize charging efficiency, achieve fast charging, and reduce the impact on battery life.

[0055] In some embodiments, the charging management unit 104 further includes a power meter, which is used to detect power parameters of the energy storage device 20 , and the first output terminal of the charging IC is connected to the energy storage device through the power meter.

[0056] For example, the fuel gauge can monitor key parameters of the energy storage device 20, such as the remaining power, voltage, current, and temperature, and provide real-time status information of the energy storage device 20. The fuel gauge and the charging IC work together to optimize the efficiency of the energy storage device 20 through precise power measurement and charging control, extending the battery life of the energy storage device 20 and reducing charging time. For example, when the charging IC detects that the energy storage device 20 is low on power, it can provide more charging current to achieve rapid charging. When it detects that the energy storage device 20 is nearly fully charged, the charging IC automatically reduces the charging current to avoid overcharging the battery and extend battery life.

[0057] In some embodiments, the signal output port 105 includes a first signal output port and a second signal output port, and the protection circuit 10 further includes a first capacitor, the first signal output port is connected to the first end of the first capacitor, and the second signal output port is connected to the second end of the capacitor;

[0058] The load 20 is connected to the first signal output port and the second signal output port respectively.

[0059] Exemplarily, the load 20 is connected in parallel with the first capacitor and then to the energy storage device 20, so that the first capacitor absorbs short-term voltage peaks in the circuit, smoothes power supply fluctuations, and reduces voltage fluctuations caused by load changes, thereby providing a more stable power supply for the load.

[0060] In some embodiments, the surge suppression unit 102 includes a surge tube, an anode of the surge tube is grounded, and a cathode is connected to the signal input port;

[0061] When the input signal of the signal input port 101 is greater than a second preset value, the surge tube is turned on to ground the signal input port.

[0062] Exemplarily, the surge tube can be a transient suppressor diode (TVS for short): utilizing the breakdown characteristics of the PN junction, it quickly turns on under overvoltage conditions where the voltage is greater than a second preset value, and introduces the surge current into the ground line to avoid the impact of the surge signal on the electronic equipment.

[0063] An embodiment of the present application provides an electronic device, which includes a protection circuit, an energy storage device, and a load as described in any one of the embodiments of the present application, wherein the protection circuit is connected to the energy storage device and the load, respectively.

[0064] See Figure 8 , Figure 8 A circuit diagram of an electronic device provided in one embodiment of the present application.

[0065] like Figure 8 As shown, the electronic device includes the protection circuit provided in an embodiment of the present application, wherein the energy storage device can be a battery, the first output end of the protection circuit is connected to the battery, and the second output end is connected to the load as a signal output port.

[0066] When a positive surge occurs, the surge signal is limited by the surge tube to protect electronic equipment from the harm of overvoltage signals; when a negative surge occurs, the unidirectional protection unit disconnects the external power supply at point A to prevent the energy absorption of the negative surge from causing the electronic equipment to reset due to insufficient voltage, thereby improving the user experience.

[0067] It should be understood that the terms used in this specification are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in this specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0068] It should also be understood that the term "and / or" used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, including these combinations. It should be noted that, in this article, the terms "include", "comprise" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or system that includes a series of elements includes not only those elements, but also other elements that are not explicitly listed, or also includes elements that are inherent to such process, method, article or system. In the absence of further restrictions, an element defined by the sentence "including a..." does not exclude the presence of other identical elements in the process, method, article or system that includes the element.

[0069] The serial numbers of the embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments. The above are only specific implementation methods of the present application, but the scope of protection of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in this application, and these modifications or replacements should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A protection circuit, at least for providing surge protection for an energy storage device, characterized in that: The protection circuit includes: a signal input port, a surge suppression unit, a circuit protection unit, a charging management unit and a signal output port; A first end of the surge suppression unit is connected to the signal input port, and a second end of the surge suppression unit is grounded; The first end of the circuit protection unit is connected to the signal input port, the second end of the circuit protection unit is connected to the input end of the charging management unit, the first output end of the charging management unit is connected to the energy storage device, and the second output end of the charging management unit is connected to the signal output port, and the signal output port is used to connect to a load; When the input signal of the signal input port is less than a first preset value, the circuit protection unit disconnects the connection path between the signal input port and the energy storage device; When the input signal of the signal input port is greater than or equal to the first preset value and less than a second preset value, the connection path between the signal input port and the energy storage device is connected; When the input signal of the signal input port is greater than the second preset value, the surge suppression unit grounds the signal input port.

2. The protection circuit according to claim 1, wherein: The circuit protection unit includes a unidirectional protection unit, a first end of the unidirectional protection unit is connected to the signal input port, and a second end of the unidirectional protection unit is connected to the input end of the charging management unit; the unidirectional protection unit is cut off when the input signal of the signal input port is less than a first preset value, so as to disconnect the connection path between the signal input port and the energy storage device; the unidirectional protection unit is turned on when the input signal of the signal input port is greater than or equal to the first preset value, so as to connect the connection path between the signal input port and the energy storage device.

3. The protection circuit according to claim 2, wherein: The unidirectional protection unit includes a first switching transistor and a second switching transistor, wherein a first end of the first switching transistor is connected to the signal input port, a second end of the first switching transistor is connected to the input end of the charging management unit, a control end of the first switching transistor is connected to the second end of the second switching transistor, a control end of the second switching transistor is connected to the signal input port, and a first end of the second switching transistor is grounded; When the input signal of the signal input port is less than a first preset value, the first switch tube and the second switch tube are turned off; when the input signal of the signal input port is greater than or equal to the first preset value, the first switch tube and the second switch tube are turned on.

4. The protection circuit according to claim 2, wherein: The unidirectional protection unit includes a diode, an anode of the diode is connected to the signal input port, and a cathode of the diode is connected to the input end of the charging management unit.

5. The protection circuit according to claim 2, wherein: The circuit protection unit further includes an overvoltage protection unit, wherein the input end of the overvoltage protection unit is connected to the second end of the unidirectional protection unit, and the output end of the overvoltage protection unit is connected to the input end of the charging management unit, for providing overvoltage protection for the energy storage device; And / or, the circuit protection unit also includes an overcurrent protection unit, the input end of the overcurrent protection unit is connected to the second end of the unidirectional protection unit, and the output end of the overcurrent protection unit is connected to the input end of the charging management unit, for providing overcurrent protection for the energy storage device.

6. The protection circuit according to claim 1, wherein: The charging management unit includes a charging IC, a first output end of the charging IC is connected to the energy storage device, and a second output end of the charging IC is connected to the signal output port.

7. The protection circuit according to claim 6, characterized in that: The charging management unit further includes a power meter, which is used to detect power parameters of the energy storage device. The first output terminal of the charging IC is connected to the energy storage device through the power meter.

8. The protection circuit according to claim 1, wherein: The signal output port includes a first signal output port and a second signal output port, the protection circuit further includes a first capacitor, the first signal output port is connected to a first end of the first capacitor, and the second signal output port is connected to a second end of the capacitor; The load is connected to the first signal output port and the second signal output port respectively.

9. The protection circuit according to claim 1, wherein: The surge suppression unit includes a surge tube, wherein the anode of the surge tube is grounded and the cathode is connected to the signal input port; Wherein, when the input signal of the signal input port is greater than the second preset value, the surge tube is turned on to ground the signal input port.

10. An electronic device, characterized in that: The electronic device comprises the protection circuit according to any one of claims 1 to 9, an energy storage device, and a load, wherein the protection circuit is connected to the energy storage device and the load respectively.

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