Low-power-consumption display screen power supply circuit and circuit protection board

Abstract

The low-power-consumption display screen power supply circuit comprises the following modules: a main power supply module, a charge pump module, an external BOOST module, a VGH output module and a VGL output module. The main power supply module provides initial power for other modules; the charge pump module converts the initial power supply into a VSN power supply and outputs the VSN power supply to the display screen; the external BOOST module converts the initial power supply into a VSP power supply and outputs the VSP power supply to the display screen; the VGH output module converts the initial power supply into a VGH power supply through the charge pump module and outputs the VGH power supply to the display screen; and the VGL output module converts the initial power supply into a VGL power supply through the charge pump module and outputs the VGL power supply to the display screen. According to the low-power-consumption display screen power supply circuit, various voltages required by a display screen are efficiently provided through the main power supply module and the plurality of submodules which cooperate accurately. The service life of the power supply is prolonged, heat generation is reduced, and long-term stable operation is ensured. Meanwhile, the modular design simplifies the system structure, is convenient to maintain and expand, and improves the overall reliability.

Description

A low-power display screen power supply circuit and circuit protection board Technical Field

[0001] This application relates to the field of display technology, specifically to a low-power display power supply circuit and circuit protection board. Background Technology

[0002] Improving the power efficiency of displays and extending battery life has become a key technical challenge in modern electronic product design. As one of the most energy-consuming components in electronic devices, especially in technologies like Liquid Crystal Displays (LCDs) and Organic Light Emitting Diodes (OLEDs), the power management of displays directly impacts the overall energy efficiency and user experience. Therefore, optimizing display power design to reduce energy consumption and extend battery life has become a crucial issue for many R&D teams and engineers during the product design phase.

[0003] In liquid crystal displays (LCDs) and organic light-emitting diode (OLEDs), power supply design goes beyond simple voltage conversion and regulation. It encompasses meeting diverse voltage requirements (such as high voltage VGH and low voltage VGL) and ensuring the stability, efficiency, and reliability of the power system. Traditional power management solutions, especially those based on linear regulated power supplies and switching power supplies (such as BOOST power modules), while providing the necessary voltage conversion to some extent, often suffer from low efficiency, large size, and high cost in practical applications. These inherent drawbacks not only lead to energy waste but also increase product size and weight, thus impacting portability and market competitiveness.

[0004] Especially in the field of low-power display devices, traditional power solutions often struggle to meet the stringent requirements of both power consumption and space constraints. For example, in small mobile devices such as wearables, smartwatches, and fitness trackers, battery capacity is limited, and power consumption must be extremely low to ensure extended use. In these devices, the display's driving circuitry often becomes the bottleneck for overall energy efficiency. Therefore, achieving efficient power management while maintaining rich functionality and clear display quality has become a major design challenge. Summary of the Invention

[0005] To address the above technical issues, this application provides a low-power display power supply circuit and circuit protection board.

[0006] In a first aspect, this application proposes a low-power display screen power supply circuit, the low-power display screen power supply circuit comprising:

[0007] Main power supply module, charge pump module, external BOOST module, VGH output module and VGL output module;

[0008] The main power module provides initial power to the other modules;

[0009] The charge pump module is used to convert the initial power supply into VSN power and output it to the display screen;

[0010] The external BOOST module is used to convert the initial power supply into VSP power supply and output it to the display screen;

[0011] The VGH output module is connected to the charge pump module and is used to convert the initial power supply into VGH power supply and output it to the display screen;

[0012] The VGL output module is connected to the charge pump module and is used to convert the initial power supply into VGL power supply and output it to the display screen.

[0013] This low-power display power circuit design integrates multiple high-efficiency modules (such as charge pumps and BOOST modules) to reduce energy loss and improve power efficiency. Power optimization and stability: Ensures stable power supply, improving display quality and system stability. Extended battery life: Optimizes power consumption and extends battery life. Space and cost advantages: Integrated modules reduce size and cost, making it suitable for compact devices. Flexible adaptation to different needs: Provides multiple voltage outputs to meet the requirements of different display technologies.

[0014] Furthermore, the charge pump module includes: a first diode group, a second diode group, a third diode group, a fourth diode group, and a fifth diode group; the input terminal of the first diode group is connected to the main power supply module; the input terminal of the second diode group is connected to the output terminal of the first diode group; the input terminal of the third diode group is connected to the output terminal of the second diode group; the output terminal of the third diode group is connected to the VGH output module; the output terminal of the fourth diode group is grounded, and its input terminal is connected to the display screen; the output terminal of the fifth diode group is connected to the input terminal of the fourth diode group, and its input terminal is connected to the VGL output module; the intermediate terminals of the first diode group, the second diode group, and the third diode group are connected to the intermediate terminals of the fourth diode group and the fifth diode group through multiple capacitors.

[0015] Furthermore, the first diode group, the second diode group, the third diode group, the fourth diode group, and the fifth diode group are each composed of two diodes connected in series.

[0016] By progressively switching and regulating the voltage through a series of diode groups (first to fifth diode groups), the power supply can ensure that it can provide accurate voltage output to the display screen according to different needs.

[0017] Gradual distribution: The output of each diode group is connected to a different voltage module (such as VGH and VGL), thereby achieving different voltage outputs to provide the required power to different parts of the display.

[0018] Multiple capacitors are connected to diode groups: Connecting capacitors to the middle terminals of each diode group helps smooth current changes, reduce voltage fluctuations, and improve system stability. This design ensures power supply stability and prevents excessively high or low voltage from affecting the display screen.

[0019] Each diode group consists of two diodes connected in series, further improving energy conversion efficiency while reducing energy loss. Precise diode selection and series connection methods enable more efficient voltage conversion.

[0020] In summary, this design, through a hierarchical structure of multiple diode groups and capacitor connections, can stably and efficiently provide the display with the required voltage outputs, ensuring efficient system operation, reducing power fluctuations and losses, and improving power management performance.

[0021] Furthermore, the external BOOST module includes a BOOST boost chip, the input of which is connected to the main power module, and the output of which is connected to the display screen.

[0022] By using the BOOST boost chip, the system can increase the input voltage of the future power module and provide a higher voltage to the display screen at the output. This is especially important in applications that require high voltage to drive the display screen, ensuring its normal display operation.

[0023] The BOOST module reduces the complexity of multi-stage conversion by boosting low-voltage input to the required high voltage, making the entire power system simpler and more efficient, and reducing reliance on multiple power modules.

[0024] The BOOST module's input is directly connected to the main power module, and its output is directly connected to the display screen, forming a simple power path, reducing intermediate links, and improving system reliability.

[0025] Because the BOOST module can provide a stable high voltage, the display screen can obtain sufficient power, thereby ensuring the clarity and stability of the display effect, which is especially effective in display technologies that require high voltage to drive correctly (such as LCD, OLED, etc.).

[0026] Furthermore, the VGH output module includes: a VGH transistor, a first VGH resistor, a second VGH resistor, a third VGH resistor, a VGH diode, and a VGH capacitor; one end of the first VGH resistor is connected to the collector of the VGH transistor, and the other end is connected to the collector electrode of the VGH transistor; one end of the second VGH resistor is connected in parallel with the VGH transistor; one end of the third VGH resistor is connected to the emitter of the VGH transistor, and the other end is grounded; one end of the VGH capacitor is connected to the emitter of the VGH transistor, and the other end is grounded; one end of the VGH diode is connected to the base of the VGH transistor, and the other end is grounded; the collector electrode of the VGH transistor is connected to the charge pump module.

[0027] The VGH output module can provide a stable high voltage, which is crucial for the operation of the display, especially in situations where high voltage (such as VGH voltage) is required to drive the display.

[0028] The combination of diodes and resistors protects the circuit from excessive or reverse current damage to the VGH transistor. At the same time, the capacitor smooths the output voltage, reduces electrical noise, and improves system stability.

[0029] The VGH transistor, through its different resistor connection methods and parallel settings, can adjust the output voltage characteristics, enabling the VGH module to adapt to different load requirements, provide accurate voltage output, and meet the requirements of loads such as displays.

[0030] In conjunction with the charge pump module, the VGH module can further boost the voltage, providing the required high voltage to ensure stable operation of the display.

[0031] Furthermore, the VGL output module includes: a VGL transistor, a VGL first resistor, a VGL second resistor, a VGL third resistor, a VGL diode, and a VGL capacitor; one end of the VGL first resistor is connected to the collector of the VGL transistor, and the other end is connected to the collector electrode of the VGL transistor; one end of the VGL second resistor is connected in parallel with the VGL transistor; one end of the VGL third resistor is connected to the emitter of the VGL transistor, and the other end is grounded; the VGL capacitor is connected in parallel with the VGL third resistor; the input terminal of the VGL diode is connected to the base of the VGL transistor, and the output terminal is grounded; the collector of the VGL transistor is connected to the charge pump module.

[0032] Stability of negative voltage output: By precisely controlling the operating state of the VGL transistor and the configuration of its surrounding resistors, capacitors and diodes, the VGL output module can provide a stable negative voltage, which is crucial for LCD displays and other circuits that require negative voltage.

[0033] The combination of diodes and resistors protects the VGL transistor and the entire circuit, preventing reverse current and excessive current from damaging the circuit and ensuring the reliability of the system.

[0034] The combined effect of resistors and capacitors enables the VGL module to precisely adjust the output voltage and current to adapt to different load requirements, thereby ensuring that devices such as displays can operate efficiently.

[0035] The addition of capacitors helps reduce voltage fluctuations and noise, providing a smoother output and improving system stability.

[0036] Collaboration with the charge pump module: By working with the charge pump module, the VGL module can boost and stabilize the voltage, providing the necessary negative voltage to ensure the display can function properly and show accurate images.

[0037] Secondly, this application proposes a circuit protection board, which includes the low-power display power supply circuit and the circuit board described in the first aspect, wherein the low-power display power supply circuit is integrated on the circuit board.

[0038] This application proposes a low-power display power supply circuit, comprising the following modules: a main power supply module, a charge pump module, an external BOOST module, a VGH output module, and a VGL output module. The main power supply module provides initial power to the other modules; the charge pump module converts the initial power supply into VSN power and outputs it to the display; the external BOOST module converts the initial power supply into VSP power and outputs it to the display; the VGH output module converts the initial power supply into VGH power through the charge pump module and outputs it to the display; the VGL output module converts the initial power supply into VGL power through the charge pump module and outputs it to the display.

[0039] Compared with the prior art, this application has at least the following beneficial effects:

[0040] This low-power display power supply circuit efficiently provides the various voltages required by the display screen through a main power module and multiple precisely cooperating sub-modules. This extends the power supply's lifespan, reduces heat generation, and ensures long-term stable operation. Simultaneously, the modular design simplifies the system structure, facilitates maintenance and expansion, and enhances overall reliability. Attached Figure Description

[0041] Figure 1 is a circuit schematic diagram of an embodiment of this utility model;

[0042] Figure 2 is a power supply circuit structure diagram of an embodiment of this application. Detailed Implementation

[0043] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0044] Example 1:

[0045] As shown in Figure 1, this application proposes a low-power display power supply circuit, which includes:

[0046] Main power supply module, charge pump module, external BOOST module, VGH output module and VGL output module;

[0047] The main power module provides initial power to the other modules;

[0048] The charge pump module is used to convert the initial power supply into VSN power and output it to the display screen;

[0049] The external BOOST module is used to convert the initial power supply into VSP power supply and output it to the display screen;

[0050] The VGH output module is connected to the charge pump module and is used to convert the initial power supply into VGH power supply and output it to the display screen;

[0051] The VGL output module is connected to the charge pump module and is used to convert the initial power supply into VGL power supply and output it to the display screen.

[0052] This low-power display power circuit design integrates multiple high-efficiency modules (such as charge pumps and BOOST modules) to reduce energy loss and improve power efficiency. Power optimization and stability: Ensures stable power supply, improving display quality and system stability. Extended battery life: Optimizes power consumption and extends battery life. Space and cost advantages: Integrated modules reduce size and cost, making it suitable for compact devices. Flexible adaptation to different needs: Provides multiple voltage outputs to meet the requirements of different display technologies.

[0053] Figure 2 shows a low-power display power supply circuit structure diagram according to an embodiment of this application.

[0054] In this embodiment of the present invention, optionally, the charge pump module includes: a first diode group, a second diode group, a third diode group, a fourth diode group, and a fifth diode group; the input terminal of the first diode group is connected to the main power supply module; the input terminal of the second diode group is connected to the output terminal of the first diode group; the input terminal of the third diode group is connected to the output terminal of the second diode group; the output terminal of the third diode group is connected to the VGH output module; the output terminal of the fourth diode group is grounded, and its input terminal is connected to the display screen; the output terminal of the fifth diode group is connected to the input terminal of the fourth diode group, and its input terminal is connected to the VGL output module; the intermediate terminals of the first diode group, the second diode group, and the third diode group are connected to the intermediate terminals of the fourth diode group and the fifth diode group through multiple capacitors.

[0055] In this embodiment of the present invention, optionally, the first diode group, the second diode group, the third diode group, the fourth diode group, and the fifth diode group are composed of two diodes connected in series.

[0056] By progressively switching and regulating the voltage through a series of diode groups (first to fifth diode groups), the power supply can ensure that it can provide accurate voltage output to the display screen according to different needs.

[0057] Each diode group's output is connected to a different voltage module (such as VGH and VGL), thereby achieving different voltage outputs to provide the necessary power to different parts of the display screen.

[0058] Connecting capacitors to the middle terminals of each diode group helps smooth current changes, reduce voltage fluctuations, and improve system stability. This design ensures power supply stability and prevents excessively high or low voltage from affecting the display screen.

[0059] Each diode group consists of two diodes connected in series, further improving energy conversion efficiency while reducing energy loss. Precise diode selection and series connection methods enable more efficient voltage conversion.

[0060] In summary, this design, through a hierarchical structure of multiple diode groups and capacitor connections, can stably and efficiently provide the display with the required voltage outputs, ensuring efficient system operation, reducing power fluctuations and losses, and improving power management performance.

[0061] In this embodiment of the present invention, optionally, the external BOOST module includes a BOOST boost chip, wherein the input terminal of the BOOST boost chip is connected to the main power module and the output terminal is connected to the display screen.

[0062] By using the BOOST boost chip, the system can increase the input voltage of the future power module and provide a higher voltage to the display screen at the output. This is especially important in applications that require high voltage to drive the display screen, ensuring its normal display operation.

[0063] The BOOST module reduces the complexity of multi-stage conversion by boosting low-voltage input to the required high voltage, making the entire power system simpler and more efficient, and reducing reliance on multiple power modules.

[0064] The BOOST module's input is directly connected to the main power module, and its output is directly connected to the display screen, forming a simple power path, reducing intermediate links, and improving system reliability.

[0065] Because the BOOST module can provide a stable high voltage, the display screen can obtain sufficient power, thereby ensuring the clarity and stability of the display effect, which is especially effective in display technologies that require high voltage to drive correctly (such as LCD, OLED, etc.).

[0066] In this embodiment of the present invention, optionally, the VGH output module includes: a VGH transistor, a first VGH resistor, a second VGH resistor, a third VGH resistor, a VGH diode, and a VGH capacitor; one end of the first VGH resistor is connected to the collector of the VGH transistor, and the other end is connected to the collector electrode of the VGH transistor; one end of the second VGH resistor is connected in parallel with the VGH transistor; one end of the third VGH resistor is connected to the emitter of the VGH transistor, and the other end is grounded; one end of the VGH capacitor is connected to the emitter of the VGH transistor, and the other end is grounded; one end of the VGH diode is connected to the base of the VGH transistor, and the other end is grounded; the collector electrode of the VGH transistor is connected to the charge pump module.

[0067] The VGH output module can provide a stable high voltage, which is crucial for the operation of the display, especially in situations where high voltage (such as VGH voltage) is required to drive the display.

[0068] The combination of diodes and resistors protects the circuit from excessive or reverse current damage to the VGH transistor. At the same time, the capacitor smooths the output voltage, reduces electrical noise, and improves system stability.

[0069] The VGH transistor, through its different resistor connection methods and parallel settings, can adjust the output voltage characteristics, enabling the VGH module to adapt to different load requirements, provide accurate voltage output, and meet the requirements of loads such as displays.

[0070] In conjunction with the charge pump module, the VGH module can further boost the voltage, providing the required high voltage to ensure stable operation of the display.

[0071] The first resistor VGH is connected at one end to the collector of the VGH transistor, and at the other end to the collector of the transistor, forming a current path to help regulate the stability of the current and the characteristics of the output.

[0072] The second resistor VGH is connected in parallel with the transistor VGH and may be used to regulate current and voltage, helping to stabilize the voltage and protect the circuit.

[0073] The third resistor in VGH is connected to the emitter of the VGH transistor and grounded, serving to shunt and stabilize the current.

[0074] The VGH capacitor is connected to the emitter of the VGH transistor and grounded. The capacitor's function may be to filter and smooth signals, reduce noise in the circuit, and ensure a stable voltage output.

[0075] The VGH diode is connected between the base of the VGH transistor and ground. It may be used to prevent reverse current, protect the transistor from damage, and help stabilize the voltage.

[0076] In this embodiment of the present invention, optionally, the VGL output module includes: a VGL transistor, a VGL first resistor, a VGL second resistor, a VGL third resistor, a VGL diode, and a VGL capacitor; one end of the VGL first resistor is connected to the collector of the VGL transistor, and the other end is connected to the collector electrode of the VGL transistor; one end of the VGL second resistor is connected in parallel with the VGL transistor; one end of the VGL third resistor is connected to the emitter of the VGL transistor, and the other end is grounded; the VGL capacitor is connected in parallel with the VGL third resistor; the input terminal of the VGL diode is connected to the base of the VGL transistor, and the output terminal is grounded; the collector electrode of the VGL transistor is connected to the charge pump module.

[0077] By precisely controlling the operating state of the VGL transistor and the configuration of its surrounding resistors, capacitors, and diodes, the VGL output module can provide a stable negative voltage, which is crucial for LCD displays and other circuits that require negative voltage.

[0078] The combination of diodes and resistors protects the VGL transistor and the entire circuit, preventing reverse current and excessive current from damaging the circuit and ensuring the reliability of the system.

[0079] The combined effect of resistors and capacitors enables the VGL module to precisely adjust the output voltage and current to adapt to different load requirements, thereby ensuring that devices such as displays can operate efficiently.

[0080] The addition of capacitors helps reduce voltage fluctuations and noise, providing a smoother output and improving system stability.

[0081] Collaboration with the charge pump module: By working with the charge pump module, the VGL module can boost and stabilize the voltage, providing the necessary negative voltage to ensure the display can function properly and show accurate images.

[0082] The first resistor VGL is connected at one end to the collector of the VGL transistor, and at the other end (possibly in parallel). Its function is related to the operating state of the VGL transistor, helping to stabilize the current and protect the circuit.

[0083] In negative voltage applications, this connection helps ensure a stable current and prevents it from becoming too high and damaging the circuit.

[0084] The second resistor VGL is connected in parallel with the VGL transistor. It may be used to improve current flow, reduce noise, or help form the load characteristics of the circuit.

[0085] Its function is to provide a stable parallel path, ensuring that the VGL transistor can work efficiently and provide a stable negative voltage.

[0086] One end of the third resistor in VGL is connected to the emitter of the VGL transistor, and the other end is grounded. Its function is to control the current flow and ensure current stability.

[0087] Since the emitter is directly grounded, the function of this resistor is to limit the emitter current and ensure that the system operates within a suitable operating range.

[0088] The VGL capacitor is connected in parallel with the VGL third resistor to smooth the voltage and reduce noise and fluctuations in the circuit.

[0089] When outputting a negative voltage, the capacitor's function is to stabilize the voltage output, prevent voltage fluctuations or instantaneous changes, and ensure the stable operation of the system.

[0090] The input terminal of the VGL diode is connected to the base of the VGL transistor, and the output terminal is grounded. Its function is to prevent reverse current from flowing into the base of the VGL transistor, thus protecting the transistor from damage.

[0091] In addition, diodes help maintain circuit stability and prevent damage that may be caused by reverse current flow.

[0092] The charge pump module is responsible for boosting the voltage to the required negative voltage. It is connected to the collector of the VGL transistor and increases the output voltage through a voltage conversion mechanism.

[0093] Example 2:

[0094] This application proposes a circuit protection board, which includes the low-power display power supply circuit and the circuit board described in the first aspect, wherein the low-power display power supply circuit is integrated on the circuit board.

[0095] This application proposes a low-power display power supply circuit, comprising the following modules: a main power supply module, a charge pump module, an external BOOST module, a VGH output module, and a VGL output module. The main power supply module provides initial power to the other modules; the charge pump module converts the initial power supply into VSN power and outputs it to the display; the external BOOST module converts the initial power supply into VSP power and outputs it to the display; the VGH output module converts the initial power supply into VGH power through the charge pump module and outputs it to the display; the VGL output module converts the initial power supply into VGL power through the charge pump module and outputs it to the display. This low-power display power supply circuit efficiently provides the various voltages required by the display through the main power supply module and multiple precisely cooperating sub-modules. This extends the power supply lifespan, reduces heat generation, and ensures long-term stable operation. Simultaneously, the modular design simplifies the system structure, facilitates maintenance and expansion, and improves overall reliability.

[0096] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0097] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that:

[0098] Various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this utility model, the scope of which is defined by the claims and their equivalents.

Claims

1. A low-power display screen power supply circuit, characterized in that, The low-power display power supply circuit includes: a main power module, a charge pump module, an external BOOST module, a VGH output module, and a VGL output module; the main power module provides initial power to the other modules; the charge pump module converts the initial power into VSN power and outputs it to the display; the external BOOST module converts the initial power into VSP power and outputs it to the display; the VGH output module is connected to the charge pump module and converts the initial power into VGH power and outputs it to the display; the VGL output module is connected to the charge pump module and converts the initial power into VGL power and outputs it to the display.

2. The low-power display power supply circuit according to claim 1, characterized in that, The charge pump module includes: a first diode group, a second diode group, a third diode group, a fourth diode group, and a fifth diode group; the input terminal of the first diode group is connected to the main power supply module; the input terminal of the second diode group is connected to the output terminal of the first diode group; the input terminal of the third diode group is connected to the output terminal of the second diode group; the output terminal of the third diode group is connected to the VGH output module; the output terminal of the fourth diode group is grounded, and its input terminal is connected to the display screen; the output terminal of the fifth diode group is connected to the input terminal of the fourth diode group, and its input terminal is connected to the VGL output module; the intermediate terminals of the first diode group, the second diode group, and the third diode group are connected to the intermediate terminals of the fourth diode group and the fifth diode group through multiple capacitors.

3. The low-power display power supply circuit according to claim 2, characterized in that, The first diode group, the second diode group, the third diode group, the fourth diode group, and the fifth diode group are each composed of two diodes connected in series.

4. The low-power display power supply circuit according to claim 1, characterized in that, The external BOOST module includes a BOOST boost chip, the input of which is connected to the main power module and the output of which is connected to the display screen.

5. The low-power display power supply circuit according to claim 1, characterized in that, The VGH output module includes: a VGH transistor, a first VGH resistor, a second VGH resistor, a third VGH resistor, a VGH diode, and a VGH capacitor; one end of the first VGH resistor is connected to the collector of the VGH transistor, and the other end is connected to the collector electrode of the VGH transistor; one end of the second VGH resistor is connected in parallel with the VGH transistor; one end of the third VGH resistor is connected to the emitter of the VGH transistor, and the other end is grounded; one end of the VGH capacitor is connected to the emitter of the VGH transistor, and the other end is grounded; one end of the VGH diode is connected to the base of the VGH transistor, and the other end is grounded; the collector electrode of the VGH transistor is connected to the charge pump module.

6. The low-power display power supply circuit according to claim 1, characterized in that, The VGL output module includes: a VGL transistor, a VGL first resistor, a VGL second resistor, a VGL third resistor, a VGL diode, and a VGL capacitor; one end of the VGL first resistor is connected to the collector of the VGL transistor, and the other end is connected to the collector electrode of the VGL transistor; one end of the VGL second resistor is connected in parallel with the VGL transistor; one end of the VGL third resistor is connected to the emitter of the VGL transistor, and the other end is grounded; the VGL capacitor is connected in parallel with the VGL third resistor; the input terminal of the VGL diode is connected to the base of the VGL transistor, and the output terminal is grounded; the collector of the VGL transistor is connected to the charge pump module.

7. A circuit protection board, the circuit protection board comprising the low-power display power supply circuit of any one of claims 1-6 and a circuit board, wherein the low-power display power supply circuit is integrated on the circuit board.

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