Voltage regulating circuit, system and display device

Abstract

The application discloses a voltage regulating circuit, system and display device, the voltage regulating circuit comprises a voltage comparator, a switch module and a voltage regulating module, the output end of the voltage regulating module is connected with the positive input end of the voltage comparator and the input end of a display device, the negative input end of the voltage comparator is grounded, the output end of the voltage comparator is connected with the input end of the switch module, and the output end of the switch module is connected with the input end of the voltage regulating module; the voltage comparator is used for transmitting a first signal to the switch module when the voltage at the positive input end is greater than the voltage at the negative input end; the switch module is used for transmitting a second signal to the voltage regulating module according to the first signal; and the voltage regulating module is used for regulating the input voltage to obtain an output voltage according to the received voltage regulating control signal and the second signal, and outputting the output voltage through the output end of the voltage regulating module. The negative input end of the voltage comparator is grounded, so that the voltage regulating process is not affected by the rising rate of the output voltage.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electronics, and in particular to a voltage regulating circuit, system and display device. BACKGROUND

[0002] Generally, for wearable or mobile organic light-emitting diode (OLED) products, the output voltage AVDD of the included light-emitting diodes is usually regulated by a power management integrated circuit (PMIC), but the specific value of the voltage regulation needs to be controlled by an external controller. The PMIC usually communicates with the external controller using a single-wire (1-swire) or double-wire (2-swire) communication protocol, and the voltage regulation is controlled by the external controller by issuing instructions to the PMIC through the swire signal.

[0003] Currently, the signal that starts the voltage regulating process is usually determined according to whether the voltage value of the voltage to be regulated (AVDD) reaches a reference voltage. When the voltage value of AVDD reaches the reference voltage, the external controller issues an instruction to the PMIC to adjust the voltage value of AVDD.

[0004] However, during the voltage adjustment process, the voltage output rate is affected by many factors such as the charging and discharging of the output capacitor of the product, the back-end load condition, and the power-on / off rate. Therefore, in each voltage regulating process, the load of the capacitor will be different, resulting in a difference in the voltage rise rate, which causes the time to reach the reference voltage to be different, thereby affecting the accuracy of the voltage regulation. SUMMARY

[0005] Therefore, the present application provides a voltage regulating circuit, system and display device to solve the problem of unstable accuracy of voltage regulation in the conventional solution.

[0006] The first aspect of the present application provides a voltage regulating circuit, comprising: a voltage comparator, a switching module and a voltage regulating module, the output end of the voltage regulating module being connected to the positive input end of the voltage comparator and the input end of a display device, the negative input end of the voltage comparator being grounded, the output end of the voltage comparator being connected to the input end of the switching module, and the output end of the switching module being connected to the input end of the voltage regulating module; the voltage comparator is configured to transmit a first signal to the switching module when the voltage at the positive input end is greater than the voltage at the negative input end; the switching module is configured to transmit a second signal to the voltage regulating module according to the first signal; and the voltage regulating module is configured to regulate the input voltage according to the received voltage regulating control signal and the second signal to obtain an output voltage, and output the output voltage through the output end of the voltage regulating module.

[0007] Optionally, the switch module comprises: a jitter elimination module and a transistor, an input end of the jitter elimination module is connected with an output end of the voltage comparator, an output end of the jitter elimination module is connected with the transistor, and an output end of the transistor is connected with an input end of the voltage regulation module; the jitter elimination module is configured to filter noise in the first signal, obtain the second signal, and output the second signal to the transistor; and the transistor is configured to be turned on according to the second signal.

[0008] Optionally, the transistor is an NMOS transistor.

[0009] Optionally, the voltage regulation module is configured to output a voltage to a positive input end of the voltage comparator when a voltage value of the input voltage rises to an under-voltage protection value, and output an output voltage by regulating the input voltage according to a received voltage regulation control signal after receiving the second signal.

[0010] Optionally, the voltage regulation control signal changes from a low level to a high level after a delay of a first time value when the voltage value of the input voltage rises to the under-voltage protection value, and switches between the high level and the low level after a delay of a second time value; and the voltage regulation module is configured to switch between the high level and the low level of the voltage regulation control signal according to a number of times of switching after receiving the second signal, and output an output voltage by regulating the input voltage.

[0011] Optionally, the voltage regulation module comprises: a voltage regulator and a counter; the counter is configured to count a number of times of continuous switching between a high level and a low level of the voltage regulation control signal after receiving the second signal; and the voltage regulator is configured to output the output voltage by regulating the input voltage according to a count value counted by the counter.

[0012] Optionally, the voltage regulator outputs different output voltages by regulating the input voltage according to different count values.

[0013] The second aspect of the present application provides a voltage regulation system, comprising: a voltage regulation circuit according to the first aspect of the embodiments, a control device, and a power supply device; the power supply device is configured to input a voltage to the voltage regulation circuit and the control device; and the control device is configured to send a voltage regulation control signal to an input end of the voltage regulation circuit.

[0014] Optionally, the control device is configured to change the voltage regulation control signal from a low level to a high level after a delay of a first time value when a voltage value of the input voltage of the power supply device rises to an under-voltage protection value, and control the voltage regulation control signal to switch between the high level and the low level according to a preset number of times after a delay of a second time value.

[0015] Preferably, the voltage regulating circuit is configured to output the voltage according to the preset voltage value when the input voltage of the power supply device is received and a low-level voltage regulating control signal is received.

[0016] The third aspect of the present application provides a display device, comprising a display device and the voltage regulating system according to any one of the second aspect of the present application, wherein the voltage regulating circuit of the voltage regulating system outputs a voltage to drive the display device.

[0017] The present application sets the voltage comparator to ground, so that the voltage regulating module can start regulating voltage after outputting voltage according to the input voltage, which can make the voltage regulating process not affected by the rising rate of the output voltage, and improve the accuracy of voltage regulation. In addition, since the reference voltage is not needed, the structure of the circuit can be simplified. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments or prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments described in the present application, and other drawings can also be obtained by those skilled in the art according to these drawings.

[0019] Figure 1 is a schematic diagram of the voltage regulating circuit of an embodiment of the present application;

[0020] Figure 2 is a signal timing diagram suitable for the embodiments of the present application;

[0021] Figure 3 is a signal timing diagram of the voltage regulating process in the prior art;

[0022] Figure 4 is a schematic diagram of the voltage regulating circuit of another embodiment of the present application;

[0023] Figure 5 is a schematic diagram of the voltage regulating circuit of another embodiment of the present application;

[0024] Figure 6 is a schematic diagram of the voltage regulating system of an embodiment of the present application;

[0025] Figure 7 is a schematic diagram of the display device of an embodiment of the present application. DETAILED DESCRIPTION

[0026] In the following, the technical solutions in the embodiments of the present application will be described clearly and completely with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative effort shall fall within the scope of protection of the present application.

[0027] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. As used in this application and the appended claims, the singular forms "a," "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0028] It should be understood that, although the terms first, second, third, etc. can be used herein to describe various information, these terms are not intended to denote a particular order of the information. These terms are used only to distinguish one type of information from another. For example, without departing from the scope of the present application, the first information can be referred to as the second information, and similarly, the second information can be referred to as the first information. Depending on the context, the word "if' as used herein can be interpreted as "when" or "upon" or "in response to determining."

[0029] In the following, the technical solutions in the embodiments of the present application will be described clearly and completely with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative effort shall fall within the scope of protection of the present application. In the case of no conflict, each of the following embodiments and technical features can be combined with each other.

[0030] Figure 1 is a schematic diagram of a voltage regulating circuit according to an embodiment of the present application. As shown in Figure 1 the voltage regulating circuit 100 comprises:

[0031] The voltage comparator 101, the switch module 102 and the voltage regulating module 103, the output end of the voltage regulating module 103 is connected with the positive input end of the voltage comparator 101 and the input end of the display device 200, the negative input end of the voltage comparator 101 is grounded, the output end of the voltage comparator 101 is connected with the input end of the switch module 102, and the output end of the switch module 102 is connected with the input end of the voltage regulating module 103. The voltage comparator 101 is used for transmitting a first signal to the switch module 102 when the voltage at the positive input end is greater than the voltage at the negative input end. The switch module 102 is used for transmitting a second signal to the voltage regulating module 103 according to the first signal. The voltage regulating module 103 is used for regulating the input voltage to obtain an output voltage according to the received voltage regulating control signal and the second signal, and outputting the output voltage through the output end of the voltage regulating module 103.

[0032] Electronic devices such as mobile phones and computers usually include display devices for image display, which can be a liquid crystal display (LCD) or an organic light emitting diode (OLED) display screen. The display device 200 usually works by a power management integrated circuit (PMIC) in the electronic device as a power supply chip to provide a voltage, and different display scenarios or requirements usually require different voltage values for the display device 200 to work. The display device 200 can include a display panel, and the power supply voltage provides an input voltage for the PMIC, and the PMIC provides a driving voltage for the display panel after voltage regulation. Therefore, the voltage regulating circuit 100 (PMIC) of the present application first receives an input voltage provided by a power supply device such as a power supply, and after receiving the input voltage and the received voltage regulating control signal being high, the voltage regulating module 103 starts to generate a voltage AVDD and inputs AVDD to the positive input end of the voltage comparator 101. Since the negative input end of the voltage comparator 101 is grounded, the voltage comparator 101 outputs a high-level first signal to the switch module 102 after receiving AVDD. The switch module 102 transmits a second signal to the voltage regulating module 103 according to the first signal, and the voltage regulating module 103 regulates the received input voltage according to the received second signal and voltage regulating control signal to obtain an output voltage matching the requirements of the display device 200.

[0033] It should be noted that the voltage regulating control signal includes a signal for indicating the target voltage of the voltage regulating module 103.

[0034] Specifically, the voltage regulating module 103 is configured to output a voltage to the positive input end of the voltage comparator 101 when the voltage value of the input voltage rises to the under-voltage protection value, and output an output voltage by regulating the input voltage according to the received voltage regulating control signal after receiving the second signal.

[0035] The power supply module providing the input voltage is generally started when the voltage regulating circuit 100 is needed, and gradually increases the provided input voltage. In order to avoid damage to the device, the under-voltage protection value is set. When the input voltage is greater than the under-voltage protection value, the voltage regulating module 103 is normally started according to the voltage regulating control signal, and outputs AVDD, and obtains an output voltage by regulating the input voltage according to the received voltage regulating control signal after receiving the second signal. By setting the voltage regulating module 103 to output the voltage AVDD to the positive input end of the voltage comparator 101 when the voltage value of the input voltage rises to the under-voltage protection value, the under-voltage protection of each device in the circuit can be performed. At the same time, compared with the voltage regulating process in the prior art, the voltage regulating circuit 100 can directly adjust the output voltage AVDD to the voltage value required by the display device 200, which has higher efficiency.

[0036] Specifically, the voltage regulating control signal changes from low to high after the voltage value of the input voltage rises to the under-voltage protection value and a delay of the first time value, and switches between high and low after a delay of the second time value. The voltage regulating module 103 is configured to regulate the input voltage to obtain an output voltage according to the number of times of switching between high and low of the voltage regulating control signal after receiving the second signal.

[0037] According to Figure 2 As can be seen from the signal timing diagram shown in the figure, the voltage regulating control signal ACTRL rises to high after the voltage value of the input voltage VIN rises to the under-voltage protection value and a delay of the first time value T1. The reason for setting T1 is to generate ACTRL to work stably, thereby excluding the glitch interference of part of the signal. After ACTRL rises to high, the voltage regulating module 103 is normally started according to the voltage regulating control signal, and outputs AVDD. After a delay of the second time value T2, the voltage regulating module 103 works stably, further excluding the glitch interference of part of the signal. At this time, ACTRL switches between high and low, and the voltage regulating module 103 regulates the input voltage to obtain an output voltage according to the number of times of switching between high and low of the voltage regulating control signal after receiving the second signal.

[0038] It should be noted that the number of times of switching between high and low of ACTRL is related to the target voltage indicating the voltage regulating of the voltage regulating module 103. According to Figure 3The signal timing diagram in the prior art voltage regulating process can be seen that, since the voltage regulating module 103 starts to regulate voltage after the AVDD reaches the reference voltage, at least part of the times that the ACTRL switches between high level and low level can be missed, resulting in deviation of the voltage regulating result from the required voltage regulating result.

[0039] In the embodiment of the present application, by grounding the voltage comparator 101, the voltage regulating module 103 can start to regulate voltage after outputting the voltage according to the input voltage, which can make the voltage regulating process not affected by the rising rate of the output voltage, and improve the accuracy of voltage regulation. In addition, since the reference voltage is not required, the structure of the circuit can be simplified.

[0040] Figure 4 is a schematic diagram of the voltage regulating circuit of another embodiment of the present application, as Figure 4 The switch module 102 includes a jitter elimination module 1021 and a transistor 1022, the input end of the jitter elimination module 1021 is connected with the output end of the voltage comparator 101, the output end of the jitter elimination module 1021 is connected with the transistor 1022, and the output end of the transistor 1022 is connected with the input end of the voltage regulating module 103. The jitter elimination module 1021 is used to filter the noise in the first signal, obtain the second signal, and output the second signal to the transistor 1022. The transistor 1022 is used to conduct according to the second signal.

[0041] Since the negative input end of the voltage comparator 101 is grounded, the reference voltage provided by the ground is relatively "dirty" compared with the stable voltage supply end, so the voltage comparator 101 is disturbed more, and therefore the jitter elimination module 1021 is arranged in the switch module 102. After receiving the first signal output by the output end of the voltage comparator 101, the jitter elimination module 1021 filters the noise in the first signal. Noise refers to the signal interference caused by some external energy during signal transmission. Noise usually causes distortion of the signal. After being processed by the jitter elimination module 1021, the second signal is obtained. The transistor 1022 will be turned on after receiving the second signal, at which time the second signal of the switch module 102 will be transmitted to the input end of the voltage regulating module 103, and the voltage regulating module 103 can regulate the received input voltage according to the received second signal and the voltage regulating control signal.

[0042] Specifically, the transistor 1022 can be an NMOS tube, which is turned on when receiving the second signal of high level.

[0043] In the embodiment of the present application, the anti-shake module 1021 is arranged in the switch module 102, so that the noise in the first signal can be filtered, and the interference caused by the ground of the negative input terminal of the voltage comparator 101 can be reduced, thereby improving the accuracy of voltage regulation.

[0044] Figure 5 FIG. 3 is a schematic diagram of a voltage regulation circuit according to another embodiment of the present application. As shown in FIG. 3, the voltage regulation module 103 includes a voltage regulator 1031 and a counter 1032. The counter 1032 is configured to count the number of times that the voltage regulation control signal is switched between the high level and the low level after receiving the second signal. The voltage regulator 1031 is configured to regulate the input voltage to obtain the output voltage according to the count value obtained by the counter 1032. Figure 5

[0045] In the voltage regulation process, the number of times that the ACTRL is switched between the high level and the low level is related to the target voltage indicating the voltage regulation of the voltage regulation module 103. Therefore, the counter 1032 is arranged in the voltage regulation module 103. After receiving the second signal, the counter 1032 counts the number of times that the voltage regulation control signal is switched between the high level and the low level, and the obtained count value indicates the target voltage required by the display device 200. The voltage regulator 1031 adjusts the input voltage according to the count value obtained by the counter 1032, so as to obtain the output voltage AVDD matching the voltage value of the target voltage.

[0046] Specifically, the voltage regulator 1031 regulates the input voltage to obtain different output voltages according to different count values. For example, when the number of times that the voltage regulation control signal is switched between the high level and the low level is pulse = 1, the target voltage is 7.9 V, when pulse = 2, the target voltage is 8.2 V, and when pulse = 3, the target voltage is 8.5 V.

[0047] In the embodiment of the present application, the counter 1032 is arranged, and the voltage value of the output voltage can be accurately controlled by the voltage regulator 1031.

[0048] Figure 6 FIG. 4 is a schematic diagram of a voltage regulation system according to an embodiment of the present application. As shown in FIG. 4, the voltage regulation system 300 includes the voltage regulation circuit 100, a control device 301 and a power supply device 302. The power supply device 302 is configured to input the voltage to the voltage regulation circuit 100 and the control device 301. The control device 301 is configured to send the voltage regulation control signal to the input terminal of the voltage regulation circuit 100. Figure 6

[0049] ​​The control device 301 can be a display driver IC (DDIC). After the control device 301 receives the input voltage provided by the power supply device 302, a high-level voltage control signal is generated and sent to the input end of the voltage regulating circuit 100 through a control bit single-wire (1-Swire) interface or a control bit double-wire (2-Swire) interface. The voltage regulating circuit 100 first receives the input voltage provided by the power supply device 302. After receiving the input voltage and the received voltage control signal is high level, the voltage regulating module in the voltage regulating circuit 100 starts to generate the voltage AVDD and inputs the AVDD to the positive input end of the voltage comparator in the voltage regulating circuit 100. Since the negative input end of the voltage comparator in the voltage regulating circuit 100 is grounded, the voltage comparator in the voltage regulating circuit 100 outputs a high-level first signal to the switch module in the voltage regulating circuit 100 after receiving the AVDD. The switch module in the voltage regulating circuit 100 transmits a second signal to the voltage regulating module in the voltage regulating circuit 100 according to the first signal. At this time, the voltage regulating module in the voltage regulating circuit 100 regulates the received input voltage according to the received second signal and the voltage control signal to obtain an output voltage matching the requirements of the display device 200.

[0050] Specifically, the control device 301 is configured to change the voltage control signal from low level to high level after the voltage value of the input voltage of the power supply device 302 rises to the under-voltage protection value and a delay of a first time value, and change the voltage control signal between high level and low level according to a preset number of times after a delay of a second time value.

[0051] The control device 301 generates the high-level voltage regulation control signal ACTRL when the voltage value of the input voltage VIN provided by the power supply device 302 rises to the under-voltage protection value and after a delay of the first time value T1. The reason for setting T1 is to enable stable operation of ACTRL and to exclude the interference of glitches in some signals. After the voltage regulation control signal ACTRL rises to the high level, the voltage regulation circuit 100 is normally started according to the voltage regulation control signal, and AVDD is output. After a delay of the second time value T2, the voltage regulation circuit 100 is stably operated, and further interference of glitches in some signals is excluded. At this time, the control device 301 controls the switching of ACTRL between the high level and the low level in order to indicate the voltage value of the target voltage that needs to be adjusted by the voltage regulation circuit 100. The number of times of switching of ACTRL between the high level and the low level is related to the target voltage that needs to be regulated by the voltage regulation module 103. For example, when the number of times of continuously switching of the voltage regulation control signal between the high level and the low level is pulse = 1, the target voltage is 7.9 V, when pulse = 2, the target voltage is 8.2 V, and when pulse = 3, the target voltage is 8.5 V. Meanwhile, the voltage regulation circuit 100 obtains the output voltage by regulating the input voltage according to the number of times of switching of the voltage regulation control signal between the high level and the low level. By setting the first time value and the second time value, the control device 301 and the voltage regulation circuit 100 can be stably operated during the voltage regulation process, and thus the accuracy of the voltage regulation is improved.

[0052] Specifically, the voltage regulation circuit 100 is configured to output the voltage according to the preset voltage value when the input voltage of the power supply device 302 is received and the low-level voltage regulation control signal is received.

[0053] The voltage regulation circuit 100 is normally started to output AVDD after receiving the input voltage of the power supply device 302. At this time, the voltage regulation may not be needed, the voltage regulation control signal output by the control device 301 is low level, the switch module in the voltage regulation circuit 100 is not turned on, the voltage comparator in the voltage regulation circuit 100 does not operate, and the voltage regulation module in the voltage regulation circuit 100 does not perform the voltage regulation function, so that the voltage AVDD is output according to the preset voltage value, and the normal use of the voltage regulation circuit 100 is ensured.

[0054] In the embodiment of the present application, the voltage comparator in the voltage regulation circuit 100 is grounded, so that the voltage regulation module can start to regulate the voltage after the voltage is output according to the input voltage. Compared with the method of starting to regulate the voltage after the voltage value of the output voltage reaches the reference voltage, the voltage regulation process is not affected by the rising rate of the output voltage, and the accuracy of the voltage regulation is improved. In addition, the circuit structure can be simplified because the reference voltage is not needed.

[0055] Figure 7 is a schematic diagram of a display device according to an embodiment of the present application,Figure 7 As shown, the display device 400 comprises the display device 200 and the voltage regulating system 300 as in the above embodiments, and the voltage regulating circuit 100 of the voltage regulating system 300 outputs a voltage to drive the display device 200.

[0056] The specific implementation of the voltage regulating system 300, the voltage regulating circuit 100 and the display device 200 in the display device 400 can refer to the corresponding description in the corresponding units of the aforementioned voltage regulating system embodiments and the corresponding description in the corresponding units of the aforementioned voltage regulating circuit embodiments, which will not be described here.

[0057] Although the present application has been shown and described with respect to one or more implementations, equivalent alterations and modifications will occur to others skilled in the art based on the foregoing description and accompanying drawings. The present application includes all such modifications and alterations and is limited only by the scope of the following claims. In particular regard to the various functions performed by the above described components (assemblies, resources, etc.), the terms used to describe such components are intended to correspond, unless otherwise indicated, to any component which performs the specified function of the described component (e.g., a functional equivalent), whether or not the structure is structurally identical to the structure shown. In this regard, the drawings accompanying the specification are high-level representations of various components (including functional blocks) and are merely meant as illustrative— not restrictive.

[0058] That is, the above-described embodiments are merely illustrative for the present application and do not thereby limit the patent scope of the present application, and any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present application, such as the mutual combination of technical features between various embodiments, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

[0059] In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0060] The above description has been given on the basis of the application. In the above description, various details are listed for the purpose of explanation. It should be understood that those skilled in the art can realize the present application without using these specific details. In other embodiments, well-known processes will not be described in detail to avoid unnecessary details making the description of the present application obscure. Therefore, the present application is not intended to be limited to the embodiments shown, but is consistent with the broadest scope consistent with the principles and features disclosed.

[0061] It should be noted that the various embodiments described in the present application and / or technical features in the various embodiments can be combined with each other in any manner without conflict, and the combination shall fall within the protection scope of the present application.

[0062] It should be understood that the specific examples in the embodiments of the present application are only to help those skilled in the art better understand the embodiments of the present application, and not to limit the scope of the embodiments of the present application, and those skilled in the art can make various improvements and modifications on the basis of the above embodiments, and these improvements or modifications shall fall within the protection scope of the present application. The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical scope disclosed by the present application, which shall be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A voltage regulating circuit, characterized by, The voltage comparator, the switch module and the voltage regulating module are connected in series. The voltage comparator is configured to transmit a first signal to the switch module when the voltage at the positive input end is greater than the voltage at the negative input end. The switch module is configured to transmit a second signal to the voltage regulating module according to the first signal. The voltage regulating module is configured to regulate the input voltage to obtain an output voltage according to the received voltage regulating control signal and the second signal, and output the output voltage through the output end of the voltage regulating module. The voltage regulating module is configured to output a voltage to the positive input end of the voltage comparator when the voltage value of the input voltage rises to an under-voltage protection value, and regulate the input voltage to obtain an output voltage according to the received voltage regulating control signal after receiving the second signal. The switch module includes a jitter elimination module and a transistor.

2. The voltage regulating circuit of claim 1, wherein, The jitter elimination module is configured to filter noise in the first signal to obtain the second signal and output the second signal to the transistor. The transistor is configured to be turned on according to the second signal. The transistor is an NMOS transistor.

3. The voltage regulating circuit of claim 2, wherein, The voltage regulating control signal changes from low level to high level after a delay of a first time value when the voltage value of the input voltage rises to an under-voltage protection value, and switches between high level and low level after a delay of a second time value.

4. The voltage regulation circuit of claim 1, wherein, The voltage regulating module is configured to regulate the input voltage to obtain an output voltage according to the number of times that the voltage regulating control signal switches between high level and low level after receiving the second signal. The voltage regulating module includes a voltage regulator and a counter.

5. The voltage regulating circuit of claim 4, wherein, The counter is configured to count the number of times that the voltage regulating control signal continuously switches between high level and low level after receiving the second signal. The voltage regulator is configured to regulate the input voltage to obtain the output voltage according to the count value obtained by the counter. The voltage regulator regulates the input voltage to obtain different output voltages according to different count values.

6. The voltage regulating circuit of claim 5, wherein, The voltage regulating circuit, the control device and the power supply device according to any one of claims 1-6.

7. A pressure regulating system characterized by, The power supply device is configured to input a voltage to the voltage regulating circuit and the control device. The control device is configured to send a voltage regulating control signal to the input end of the voltage regulating circuit.

8. The system of claim 7, wherein ​ ​ The control device is configured to change the voltage regulating control signal from low to high when the voltage value of the input voltage of the power supply device rises to an under-voltage protection value and after a delay of a first time value, and to control the voltage regulating control signal to switch between high and low according to a preset number of times after a delay of a second time value.

9. The system of claim 8, wherein, The voltage regulating circuit is configured to output a voltage according to a preset voltage value when receiving the input voltage of the power supply device and receiving the low voltage regulating control signal.

10. A display device comprising a display element and the voltage regulating system of any one of claims 7-9, wherein the output voltage of the voltage regulating circuit of the voltage regulating system drives the display element.

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