Load protection circuit, power supply device and display

Abstract

The utility model provides a load protection circuit, which comprises a voltage sampling module of which the input end is coupled with the input end of the load protection circuit and which is used for collecting the voltage of the input end; the input end of the control logic chip is coupled with the output end of the voltage sampling module, and the control logic chip is used for outputting a control signal according to the voltage of the input end of the load protection circuit and a preset voltage limit value in the control logic chip; and the control end of the first control switch is coupled with the output end of the control logic chip, and the first control switch controls the on-off of the load protection circuit under the control of a control signal. The voltage sampling module is used for sampling the voltage of the input end of the load protection circuit, and the control logic chip is used for comparing the voltage with the preset voltage limit value, so that when the voltage of the input end of the load protection circuit is larger than the preset voltage limit value, a control signal is output to switch off the first control switch; and cutting off the output of the load protection circuit. The load protection circuit provided by the utility model can protect the load from being damaged by overvoltage.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of electrical and electronic technology, and particularly relates to a load protection circuit, a power supply device and a display. BACKGROUND

[0002] For a load, the range of working voltage is generally fixed. If the voltage provided by the load power supply is higher than the normal working voltage of the load, the load may be damaged, and the load may be burned out or safety problems may be caused. For example, in the display industry, if a 19V adapter is mistakenly plugged into a display using a 12V adapter, overvoltage may cause overcurrent, and then the fuse may be burned out, thereby causing the whole machine to have no display. Therefore, a protection circuit is needed to protect the load in the case of overvoltage. CONTENT OF THE UTILITY MODEL

[0003] The application aims to provide a load protection circuit, a power supply device and a display, and aims to solve the problem of load failure caused by high voltage.

[0004] A first aspect of the embodiment of the application provides a load protection circuit, comprising:

[0005] a voltage sampling module, an input end of the voltage sampling module being coupled to an input end of the load protection circuit, and the voltage sampling module being configured to collect the voltage of the input end of the load protection circuit;

[0006] a control logic chip, an input end of the control logic chip being coupled to an output end of the voltage sampling module, and the control logic chip being configured to output a control signal according to the voltage of the input end of the load protection circuit and a voltage limit value preset in the control logic chip;

[0007] a first control switch, a control end of the first control switch being coupled to an output end of the control logic chip, and the first control switch being configured to control the on-off of the load protection circuit under the control of the control signal.

[0008] In a possible implementation manner, the load protection circuit further comprises:

[0009] a current sampling module, a first input end of the current sampling module being coupled to an output end of the load protection circuit, and an output end of the current sampling module being coupled to the control logic chip;

[0010] an overcurrent protection setting pin, the overcurrent protection setting pin being coupled to a second input end of the current sampling module.

[0011] In a possible implementation manner, the load protection circuit further comprises:

[0012] a first resistor, one end of the first resistor being coupled to the input end of the load protection circuit, and the other end of the first resistor being coupled to the input end of the voltage sampling module.

[0013] A second resistor, one end of the second resistor is coupled to the input end of the voltage sampling module, and the other end is grounded.

[0014] In a possible implementation, the load protection circuit further includes a thermal shutdown module, an output end of the thermal shutdown module is coupled to the control logic chip, the thermal shutdown module is configured to collect temperature of the load protection circuit, and convert the temperature into a voltage and output the voltage to the control logic chip.

[0015] In a possible implementation, the load protection circuit further includes a second control switch, a control end of the second control switch is coupled to an output end of the control logic chip, an input end of the second control switch is coupled to an output end of the load protection circuit, and an output end of the second control switch is grounded.

[0016] In a possible implementation, the load protection circuit further includes a voltage stabilizing module, the voltage stabilizing module is coupled between an input end of the load protection circuit and the control logic chip.

[0017] In a possible implementation, the load protection circuit further includes a driving unit, an input end of the driving unit is coupled to the control logic chip, and an output end of the driving unit is coupled to a control end of the first control switch.

[0018] In a possible implementation, the load protection circuit further includes:

[0019] A third resistor, one end of the third resistor is coupled to the overcurrent protection setting pin, and the other end is grounded.

[0020] A first capacitor, one end of the first capacitor is coupled to an output end of the load protection circuit, and the other end is grounded.

[0021] A second aspect of the embodiment of the present application provides a power supply device, including the load protection circuit as described above.

[0022] A third aspect of the embodiment of the present application provides a display, the display including the power supply device as described above.

[0023] Advantages of the present application

[0024] The application provides a load protection circuit, a power supply device and a display, comprising a voltage sampling module, a control logic chip and a first control switch, the voltage sampling module samples the voltage at the input end of the load protection circuit, and the control logic chip compares the voltage with a preset voltage limit value, so as to output a control signal to disconnect the first control switch and cut off the output of the load protection circuit when the voltage at the input end of the load protection circuit is greater than the preset voltage limit value. The load protection circuit provided by the application can effectively monitor and protect the load, prevent the load from being damaged by overvoltage, and improve the safety and stability of the entire circuit. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0026] Figure 1 The schematic diagram of the load protection circuit provided by an embodiment of the application is shown in the figure.

[0027] The figure shows the schematic diagram of the load protection circuit provided by an embodiment of the application. DETAILED DESCRIPTION

[0028] In order to make the technical problems, technical solutions and beneficial effects of the application more clearly understood, the following will further describe the application in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the application and not to limit the application.

[0029] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0030] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like, indicate directions or positions based on the directions or positions shown in the drawings, and are used for convenience in describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the application.

[0031] It should be understood that the term "comprises" as used in the specification and the appended claims indicates the presence of the described features, integers, steps, operations, elements, and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0032] It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items, and that the term "at least one of" followed by a list of two or more items means any single one of the items in the list, and that the term "one or more of" followed by a list of two or more items means any single one or plurality of the items in the list.

[0033] Furthermore, the terms "first", "second", "third", "fourth", "fifth", "sixth", etc. as used in the description and the claims are meant to merely indicate different features, and do not imply or suggest relative importance of the features so designated. Thus, a feature defined with "first", "second", "third", "fourth", "fifth", "sixth" can implicitly or explicitly include one or more of the features so designated. In the description of the application, the meaning of "plurality" is two or more, unless otherwise expressly specified.

[0034] Reference throughout this specification to "one embodiment" or "some embodiments" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the application. Thus, the appearances of the phrases "in one embodiment" or "in some embodiments" in various places throughout this specification are not necessarily all referring to the same embodiment, unless otherwise expressly specified. The terms "including", "containing", "having" and variations thereof are meant to encompass the terms "including but not limited to".

[0035] For a load, the range of working voltage is generally fixed, if the voltage provided by the load power supply is higher than the normal working voltage of the load, it may cause damage to the load, and may burn the load or cause safety problems. For example, in the display industry, if a 19V adapter is mistakenly plugged into a display using a 12V adapter, it will cause overcurrent due to overvoltage, and then burn the fuse, resulting in no display of the entire machine. Therefore, a protection circuit is needed to protect the load in the case of overvoltage.

[0036] The application provides a load protection circuit and device, comprising a voltage sampling module, a control logic chip and a first control switch, the voltage sampling module samples the voltage at the input end of the load protection circuit, and the control logic chip compares the voltage with a preset voltage limit value, so as to output a control signal to disconnect the first control switch and cut off the output of the load protection circuit when the voltage at the input end of the load protection circuit is greater than the preset voltage limit value. The load protection circuit provided by the application can effectively monitor and protect the load, so that the load is protected from overvoltage, and the safety and stability of the entire circuit are improved.

[0037] In order to illustrate the technical solutions of the application, specific embodiments are described below.

[0038] Figure 1 The application provides a load protection circuit and device, comprising a voltage sampling module, a control logic chip and a first control switch, the voltage sampling module samples the voltage at the input end of the load protection circuit, and the control logic chip compares the voltage with a preset voltage limit value, so as to output a control signal to disconnect the first control switch and cut off the output of the load protection circuit when the voltage at the input end of the load protection circuit is greater than the preset voltage limit value. The load protection circuit provided by the application can effectively monitor and protect the load, so that the load is protected from overvoltage, and the safety and stability of the entire circuit are improved.

[0039] The voltage sampling module 100 is coupled to the input end of the load protection circuit, and is used to collect the voltage at the input end of the load protection circuit.

[0040] The control logic chip 200 is coupled to the output end of the voltage sampling module 100, and is used to output a control signal according to the voltage at the input end of the load protection circuit and the voltage limit value preset in the control logic chip 200.

[0041] The first control switch 300 is coupled to the output end of the control logic chip 200, and controls the on-off of the load protection circuit under the control of the control signal.

[0042] The load protection circuit provided by the application can monitor the input voltage of the load protection circuit in real time. When the voltage exceeds the preset voltage limit value, the control logic chip will output a control signal to disconnect the first control switch, so as to cut off the output of the load protection circuit, thereby protecting the load from overvoltage, helping to improve the service life and stability of the equipment, and reducing the failure and maintenance cost caused by overvoltage.

[0043] It should be noted that those skilled in the art understand that the voltage sampling module 100 in the embodiment of the application belongs to the known technology in the art, and the core idea of the embodiment of the application is the combination of various devices. The voltage sampling module 100 can be known from the prior art in terms of structural composition, functional purpose or use method, for example, the voltage sampling module 100 can comprise:

[0044] Voltage divider: a voltage divider is an electronic component used to divide a high voltage signal into a low voltage signal. It can divide the input high voltage signal into a lower voltage signal in proportion, so that the subsequent circuit can accurately detect and process;

[0045] Analog voltage amplifier: an analog voltage amplifier is used to amplify the voltage signal after division, amplify the weak voltage signal into a stronger signal, improve the quality and reliability of the signal;

[0046] Analog-to-digital converter (ADC): an analog-to-digital converter can convert the analog voltage signal into a digital signal, so that the microprocessor or controller can process and calculate;

[0047] The present application does not limit this.

[0048] In addition, the control switch 300 can be a MOS tube (MOSFET, full name metal-oxide-semiconductor field effect transistor), or other devices that can realize the switching of on-off state under the control of control signal, the present application does not limit this.

[0049] It should be noted that the control logic chip 200 has a certain processing capability, which can read the voltage value collected by the voltage sampling module 100, compare and judge according to the preset voltage limit value, and decide whether to output the control signal to cut off the load protection circuit.

[0050] In one possible implementation, the load protection circuit further comprises:

[0051] Current sampling module 500, the first input end of the current sampling module 500 is coupled with the output end of the load protection circuit, and the output end is coupled with the control logic chip 200;

[0052] Overcurrent protection setting pin 400, the second input end of the current sampling module 500 is coupled with the overcurrent protection setting pin 400.

[0053] It should be noted that the current sampling module 500 includes a constant current source, and the size of the external resistance of the overcurrent protection setting pin 400 is set to determine the size of the voltage across the resistance, which is the protection voltage threshold. The control logic chip 200 will detect the voltage across the first control switch 300, and compare the protection voltage threshold with the voltage value across the first control switch 300. If the voltage value across the first control switch 300 exceeds the protection voltage threshold, it means that the current in the circuit is too large, and the first control switch 300 will be disconnected to protect the circuit.

[0054] It should be noted that, when the load protection circuit starts to work, there may be a large instantaneous current value, at this time the control logic chip 200 will monitor the duration of the large current, if the duration is less than the preset value, the control signal is not output, that is, the output of the load protection circuit is not cut off, so the application can prevent the Inrush Current at the moment of starting to trigger the control signal to cut off the output of the load protection circuit. When the load protection circuit is working normally, if the current at the output end of the load protection circuit is greater than the preset current limit value, the control signal is immediately sent to cut off the output of the load protection circuit.

[0055] It should be noted that, in the embodiment of the application, no discrete switch is used, because the discrete switch needs to be set and managed separately, making the circuit design complex, and when the circuit fails, each switch needs to be checked one by one to determine the fault point and repair, increasing the difficulty and cost of maintenance. In the present application, only one switch for controlling the on-off of the load protection circuit is provided, that is, in various abnormal circuit conditions, the control logic chip 200 outputs a control signal to the first control switch 300 to cut off the circuit output, thereby simplifying the circuit design and reducing the circuit cost.

[0056] In a possible implementation, the load protection circuit further comprises:

[0057] The first resistor R1 has one end coupled to the input end of the load protection circuit and the other end coupled to the input end of the voltage sampling module 100.

[0058] The second resistor R2 has one end coupled to the input end of the voltage sampling module 100 and the other end grounded.

[0059] In the embodiment, the first resistor R1 and the second resistor R2 are provided for voltage division. For different control logic chips 200, the voltage range that can be processed by the control logic chip 200 may be different, so external resistors need to be provided for voltage division to make the voltage input to the control logic chip 200 meet the requirements.

[0060] In a possible implementation, the load protection circuit further comprises a thermal shutdown module 600, the output end of the thermal shutdown module 600 is coupled to the control logic chip 200, for collecting the temperature of the load protection circuit and converting the temperature into a voltage output to the control logic chip 200.

[0061] For a better understanding of the present scheme, first of all, a brief introduction to the thermal shutdown module. Thermal shutdown module is a kind of circuit protection module, its role is when detecting the internal temperature exceeds the preset safety range, automatically shut down the circuit or related components, to prevent overheating caused by failure or damage, ensure that the circuit can be safely closed when overheating, so as to protect the safety of equipment and personnel. It should be noted that each device has its specific temperature threshold and response time, so it needs to be selected and configured according to the specific requirements of the device and the working environment.

[0062] It should be noted that the thermal shutdown module in the embodiments of the present application belongs to the prior art known to those skilled in the art, and the core idea of the embodiments of the present application is the combination of various devices. The thermal shutdown module involves structure, function or use method, which can be known from the prior art.

[0063] In the present embodiment, the thermal shutdown module 600 will continuously monitor the temperature of the load protection circuit as a whole, and convert the temperature into a voltage and compare it with the reference voltage preset in the control logic chip 200. When the voltage exceeds the reference voltage preset in the control logic chip 200, the control logic chip 200 will output a control signal to cut off the output of the load protection circuit. When the temperature drops, the corresponding voltage value will be less than the preset reference voltage. At this time, the control logic chip 200 will output a control signal to open the output of the load protection circuit, so as to ensure that the circuit can be safely closed when the temperature of the circuit is too high.

[0064] In a possible implementation, the load protection circuit further comprises a second control switch 700, the control end of the second control switch 700 is coupled to the output end of the control logic chip 200, the input end is coupled to the output end of the load protection circuit, and the output end is grounded.

[0065] It should be noted that the second control switch is provided to realize the function of output discharge. The fast output discharge function creates a path from VOUT to GND, ensuring that the load can quickly return to the "off" state of 0V, and ensuring that the disconnected or disabled load will not be floating. In the present embodiment, when the output of the load protection circuit is cut off, the second control switch 700 will be opened under the control of the control logic chip 200, so that the VOUT voltage reaches the GND level and is discharged quickly.

[0066] In a possible implementation, the load protection circuit further comprises a voltage stabilizing module 800, which is coupled between the input end of the load protection circuit and the control logic chip 200.

[0067] It should be noted that the voltage stabilizing module in the embodiments of the present application is known in the art, and the core idea of the embodiments of the present application lies in the combination of various devices. The voltage stabilizing module relates to structural components, functional purposes or use methods, which can be known from prior art.

[0068] For example, the voltage stabilizing module 800 can be a low dropout regulator (LDO). The low dropout regulator is a kind of linear voltage regulator, which has the advantages of low noise, low ripple, low heat loss, etc., and is widely used in various applications. The main structure of the LDO includes an input capacitor, a filter circuit, an amplifier, a voltage stabilizing element and an output capacitor. In the working process, the LDO first filters the input voltage to reduce voltage fluctuation, then amplifies, and finally stabilizes the voltage by the voltage stabilizing element.

[0069] In a possible implementation, the load protection circuit further includes a driving unit 900, an input end of the driving unit 900 being coupled to the control logic chip 200, and an output end of the driving unit 900 being coupled to a control end of the first control switch 300.

[0070] It should be noted that the driving unit in the embodiments of the present application is known in the art, and the core idea of the embodiments of the present application lies in the combination of various devices. The driving unit relates to structural components, functional purposes or use methods, which can be known from prior art.

[0071] For example, the driving unit 900 can be a slew rate controlled driver. Slew rate is an important parameter of an operational amplifier. It reflects the maximum rate of change of the output voltage when a step signal is input to the amplifier, and is usually expressed in V / μs. The slew rate controlled driver has a controlled slew rate to reduce inrush current, which is also called "soft start" function. By gradually increasing the charging speed of its output capacitor, it can prevent the power supply voltage from dropping due to rapid charging of the load capacitor.

[0072] In a possible implementation, the load protection circuit further includes:

[0073] a third resistor R3, one end of the third resistor R3 being coupled to the overcurrent protection setting pin 400, and the other end being grounded;

[0074] a first capacitor C1, one end of the first capacitor C1 being coupled to an output end of the load protection circuit, and the other end being grounded.

[0075] It should be noted that the current sampling module 500 includes an external constant current source, and the current passing through R3 generates a voltage, which serves as a judgment reference for the internal protection current of the chip. In addition, the first capacitor C1 is a load capacitor, which stabilizes the voltage waveform, reduces spikes, and ensures stable power supply.

[0076] The application also provides a power supply device including the load protection circuit.

[0077] The power supply device provided by the application can monitor the input voltage of the load protection circuit in real time. When the voltage exceeds the preset voltage limit value, the control logic chip outputs a control signal to make the first control switch open, thereby cutting off the output of the load protection circuit, and further protecting the load from overvoltage damage, which helps to improve the service life and stability of the equipment, and reduce the failure and maintenance cost caused by overvoltage.

[0078] The application also provides a display including the power supply device.

[0079] Currently, in the display industry, factory and after-sales data show that the burnout rate of the display is very high, because the wrong adapter causes overcurrent burnout of the fuse due to overvoltage of the display, and further causes the whole machine to have no display. Therefore, the application provides a display, which adds the above-mentioned power supply device in the display. In this way, even if the adapter of the display is inserted incorrectly, the load protection circuit will also cut off the output to ensure that the display will not be damaged due to overvoltage.

[0080] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the above-mentioned division of each functional unit and module is exemplified, and in actual application, the above-mentioned functions can be completed by different functional units and modules according to needs, that is, the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above. Each functional unit and module in the embodiment can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or software. In addition, the specific names of each functional unit and module are only for easy distinction, and do not limit the protection scope of the application. The specific working process of the unit and module in the above system can refer to the corresponding process in the foregoing method embodiments, which will not be repeated here.

[0081] In the above embodiments, the description of each embodiment has its own emphasis, and the parts not described or recorded in a certain embodiment can be referred to the related description of other embodiments.

[0082] In the embodiments of the present application, it should be understood that the disclosed apparatus / terminal device and method can be implemented in other manners. For example, the embodiments of the apparatus / terminal device described above are merely schematic; for example, the division of the modules or units is merely logical function division; an actual mapping of the embodiments of the apparatus / terminal device can be different, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections between different units, or the logical couplings or communication connections between different units, can be indirect couplings or communication connections through some interfaces, devices or units, and can be in electrical, mechanical or other forms.

[0083] The units described as separated components can or can not be physically separated, and the components displayed as units can or can not be physical units, i.e., can be located in one place, or can be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purposes of the embodiments of the present application.

[0084] In addition, each functional unit in the embodiments of the present application can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit. The integrated unit can be implemented in the form of hardware, or in the form of software functional units.

[0085] The above-described embodiments are merely used to illustrate the technical solutions of the present application, rather than limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced by equivalent technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A load protection circuit, characterized by, The load protection circuit comprises: a voltage sampling module, an input end of which is coupled to an input end of the load protection circuit, for collecting a voltage at the input end of the load protection circuit; a control logic chip, an input end of which is coupled to an output end of the voltage sampling module, for outputting a control signal according to the voltage at the input end of the load protection circuit and a voltage limit value preset in the control logic chip; a first control switch, a control end of which is coupled to an output end of the control logic chip, for controlling on-off of the load protection circuit under control of the control signal. The load protection circuit further comprises:

2. The load protection circuit of claim 1, wherein, a thermal shutdown module, an output end of which is coupled to the control logic chip, for collecting a temperature of the load protection circuit and converting the temperature into a voltage to output to the control logic chip. The load protection circuit further comprises: a current sampling module, a first input end of which is coupled to an output end of the load protection circuit, and an output end of which is coupled to the control logic chip; 3. The load protection circuit of claim 1, wherein, an overcurrent protection setting pin, which is coupled to a second input end of the current sampling module. The load protection circuit further comprises: a first resistor, one end of which is coupled to the input end of the load protection circuit, and the other end of which is coupled to an input end of the voltage sampling module; 4. The load protection circuit of claim 1, wherein, a second resistor, one end of which is coupled to the input end of the voltage sampling module, and the other end of which is grounded.

5. The load protection circuit of claim 1, wherein, The load protection circuit further comprises:

6. The load protection circuit of claim 1, wherein, a second control switch, a control end of which is coupled to an output end of the control logic chip, an input end of which is coupled to an output end of the load protection circuit, and an output end of which is grounded.

7. The load protection circuit of claim 2, wherein, The load protection circuit further comprises: a voltage stabilizing module, which is coupled between the input end of the load protection circuit and the control logic chip. The load protection circuit further comprises:

8. A power supply device characterized by comprising: a driving unit, an input end of which is coupled to the control logic chip, and an output end of which is coupled to the control end of the first control switch.

9. A display, characterized by The load protection circuit further comprises: a third resistor, one end of which is coupled to the overcurrent protection setting pin, and the other end of which is grounded; a first capacitor, one end of which is coupled to the output end of the load protection circuit, and the other end of which is grounded. The display comprises the load protection circuit according to any one of claims 1 to 7. The display comprises the power supply device according to claim 8.

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