Expansion power supply device

Abstract

The utility model provides an expansion power supply device, which is provided with a boost chip, a peripheral circuit design AVDD boost circuit, a VGH boost circuit, a VGL boost circuit and a VCOM boost circuit are additionally arranged, AVDD boost signals, VGH boost signals, VGL boost signals and VCOM boost are provided for a large-size TFT liquid crystal display during a lightening test, and compared with discrete design, the integrated circuit design has the advantages that the design is simple, the design is convenient, and the cost is low. The device is small in occupied space, high in reliability, low in energy consumption and low in failure rate.

Description

Technical Field

[0001] The utility model relates to the technical field of voltage driving of liquid crystal displays, in particular to an expansion power supply device. Background Art

[0002] TFT liquid crystal displays have gradually become standard output devices for various digital products due to their advantages of light weight, thin thickness and low power consumption. TFT liquid crystal displays can only work stably when driven by appropriate driving voltage.

[0003] Large-size TFT liquid crystal displays require external AVDD, VGH, VGL, and VCOM voltage signals to work properly. Therefore, the test board needs to provide additional AVDD, VGH, VGL, and VCOM voltage signals for the lighting test before production. The existing technology sets up separate circuits for AVDD, VGH, VGL, and VCOM, which has the disadvantages of large space occupation, low reliability, high energy consumption, and high failure rate.

[0004] Therefore, it is necessary to propose an extended power supply device that can provide AVDD, VGH, VGL, and VCOM signals in an integrated manner to solve the problems of large occupied space, low reliability, high energy consumption, and high failure rate. Utility Model Content

[0005] The utility model provides an expansion power supply device, which solves the problems of "large occupied space, low reliability, large energy consumption and high failure rate" existing in the prior art.

[0006] The utility model solves the technical problem through the following technical solutions:

[0007] An extended power supply device includes a module boost module;

[0008] The module boost module includes a boost chip, an AVDD boost circuit, a VGH boost circuit, a VGL boost circuit and a VCOM boost circuit; the AVDD boost circuit, the VGH boost circuit, the VGL boost circuit and the VCOM boost circuit share the same boost chip;

[0009] The AVDD boost circuit includes an energy storage inductor, a diode, an AVDD energy storage capacitor, a filter capacitor and an AVDD voltage divider sub-circuit; the energy storage inductor is connected between the switch signal port and the voltage input port of the boost chip; the switch signal port of the boost chip is used as the output port of the AVDD boost circuit after passing through the diode; the voltage divider sub-circuit includes a first AVDD resistor and a second AVDD resistor connected in series, one end of the first AVDD resistor is used as the output port of the AVDD boost circuit, and the other end of the first AVDD resistor is grounded after passing through the second AVDD resistor; the feedback port of the boost chip is connected between the first AVDD resistor and the second AVDD resistor, and the feedback port of the boost chip is also used as the output port of the AVDD boost circuit after passing through the filter capacitor; the output port of the AVDD boost circuit is grounded after passing through the AVDD energy storage capacitor;

[0010] The VGH boost circuit mainly includes a VGH energy storage capacitor, a VGH double diode, a VGH filter capacitor and a VGH voltage divider sub-circuit; a field effect tube port of the boost chip is connected to the 3-port of the VGH double diode after passing through the VGH energy storage capacitor; the 1-port of the VGH double diode is connected to the output port of the AVDD boost circuit, and the 2-port of the VGH double diode is connected to the VGH voltage divider sub-circuit; the VGH voltage divider sub-circuit includes a VGH first resistor and a VGH second resistor connected in series, the 2-port of the VGH double diode is grounded after passing through the VGH first resistor and the VGH second resistor, and the 2-port of the VGH double diode is also connected to the CPI port of the boost chip; the FBP port of the boost chip is connected between the VGH first resistor and the VGH second resistor; the SUP port of the boost chip is connected to the output port of the AVDD boost circuit; the DLY2 end of the boost chip is grounded after passing through the VGH filter capacitor; the VGH port of the boost chip serves as the VGH boost circuit output port of the VGH boost circuit;

[0011] The VGL boost circuit mainly includes a VGL energy storage capacitor, a VGL dual diode, a VGL voltage divider circuit, and a VGL filter capacitor; another field effect tube port of the boost chip is connected to port 3 of the VGL dual diode via the VGL energy storage capacitor; port 2 of the VGL dual diode is grounded, and port 1 of the VGL dual diode is connected to the VGL voltage divider circuit; the VGL voltage divider circuit includes a VGL first resistor and a VGL second resistor connected in series; port 1 of the VGL dual diode is grounded via the VGL first resistor and the VGL second resistor; port DLY1 of the boost chip is grounded via the VGL filter capacitor; port 1 of the VGL dual diode is the output port of the VGL boost circuit;

[0012] The VCOM boost circuit mainly includes a VCOM voltage divider sub-circuit; the VCOM voltage divider sub-circuit includes a VCOM first resistor and a VCOM second resistor connected in series; the output port of the AVDD boost circuit is connected to the signal input end of the boost chip through the VCOM voltage divider sub-circuit; the VCOM port of the boost chip is the output port of the VCOM boost circuit.

[0013] Furthermore, it also includes a backlight boost module;

[0014] The backlight boost module mainly includes a backlight boost chip, a backlight energy storage inductor, a backlight diode and a voltage divider resistor; the voltage input port of the backlight boost chip is connected to the control port; the voltage input port of the backlight boost chip obtains a switching signal after passing through the backlight energy storage inductor; the switching signal is connected to the switching port of the backlight boost chip, and the switching signal obtains a backlight anode signal after passing through the backlight diode; the feedback port of the backlight boost chip is grounded after passing through the voltage divider resistor; the signal output by the feedback port of the backlight boost chip is a backlight cathode signal.

[0015] Furthermore, the output voltage of the feedback port of the boost chip is divided by the AVDD voltage divider subcircuit to obtain a voltage output value of the AVDD boost circuit.

[0016] Furthermore, the output voltage of the FBP port of the boost chip is divided by the VGH voltage divider sub-circuit to obtain the voltage output value of the VGH boost circuit.

[0017] Furthermore, the output voltage of the FBN port of the boost chip is divided by the VGL voltage divider sub-circuit to obtain the voltage output value of the VGL boost circuit.

[0018] Furthermore, the output voltage value of the AVDD boost circuit is divided by the VCOM voltage divider subcircuit to obtain a voltage output value of the VCOM boost circuit.

[0019] Furthermore, the output current value of the backlight boost module is the quotient of the voltage value of the feedback port of the backlight boost chip and the voltage-dividing resistor.

[0020] The advantages and effects of the utility model are:

[0021] 1. Set up a boost chip, add peripheral circuit designs such as AVDD boost circuit, VGH boost circuit, VGL boost circuit and VCOM boost circuit, and provide AVDD boost signal, VGH boost signal, VGL boost signal and VCOM boost for large-size TFT liquid crystal display during lighting test. Compared with discrete design, integrated circuit design occupies less space, has higher reliability, lower energy consumption and lower failure rate.

[0022] 2. Set up a backlight boost module, and use the boost chip and energy storage inductor to obtain the backlight anode signal and backlight cathode signal to enhance and stabilize the backlight power so that the lighting test can proceed smoothly. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a circuit diagram of the module boost module of the utility model.

[0024] Figure 2 This is the circuit diagram of the backlight boost module. DETAILED DESCRIPTION

[0025] The present invention is further described below in conjunction with embodiments, but the present invention is not limited to these embodiments.

[0026] An extended power supply device includes a module boost module;

[0027] The module boost module includes a boost chip, an AVDD boost circuit, a VGH boost circuit, a VGL boost circuit and a VCOM boost circuit; the AVDD boost circuit, the VGH boost circuit, the VGL boost circuit and the VCOM boost circuit share the same boost chip;

[0028] The AVDD boost circuit includes an energy storage inductor, a diode, an AVDD energy storage capacitor, a filter capacitor and an AVDD voltage divider sub-circuit; the energy storage inductor is connected between the switch signal port and the voltage input port of the boost chip; the switch signal port of the boost chip is used as the output port of the AVDD boost circuit after passing through the diode; the voltage divider sub-circuit includes a first AVDD resistor and a second AVDD resistor connected in series, one end of the first AVDD resistor is used as the output port of the AVDD boost circuit, and the other end of the first AVDD resistor is grounded after passing through the second AVDD resistor; the feedback port of the boost chip is connected between the first AVDD resistor and the second AVDD resistor, and the feedback port of the boost chip is also used as the output port of the AVDD boost circuit after passing through the filter capacitor; the output port of the AVDD boost circuit is grounded after passing through the AVDD energy storage capacitor;

[0029] The VGH boost circuit mainly includes a VGH energy storage capacitor, a VGH double diode, a VGH filter capacitor and a VGH voltage divider sub-circuit; a field effect tube port of the boost chip is connected to the 3-port of the VGH double diode after passing through the VGH energy storage capacitor; the 1-port of the VGH double diode is connected to the output port of the AVDD boost circuit, and the 2-port of the VGH double diode is connected to the VGH voltage divider sub-circuit; the VGH voltage divider sub-circuit includes a VGH first resistor and a VGH second resistor connected in series, the 2-port of the VGH double diode is grounded after passing through the VGH first resistor and the VGH second resistor, and the 2-port of the VGH double diode is also connected to the CPI port of the boost chip; the FBP port of the boost chip is connected between the VGH first resistor and the VGH second resistor; the SUP port of the boost chip is connected to the output port of the AVDD boost circuit; the DLY2 end of the boost chip is grounded after passing through the VGH filter capacitor; the VGH port of the boost chip serves as the VGH boost circuit output port of the VGH boost circuit;

[0030] The VGL boost circuit mainly includes a VGL energy storage capacitor, a VGL dual diode, a VGL voltage divider circuit, and a VGL filter capacitor; another field effect tube port of the boost chip is connected to port 3 of the VGL dual diode via the VGL energy storage capacitor; port 2 of the VGL dual diode is grounded, and port 1 of the VGL dual diode is connected to the VGL voltage divider circuit; the VGL voltage divider circuit includes a VGL first resistor and a VGL second resistor connected in series; port 1 of the VGL dual diode is grounded via the VGL first resistor and the VGL second resistor; port DLY1 of the boost chip is grounded via the VGL filter capacitor; port 1 of the VGL dual diode is the output port of the VGL boost circuit;

[0031] The VCOM boost circuit mainly includes a VCOM voltage divider subcircuit; the VCOM voltage divider subcircuit includes a VCOM first resistor and a VCOM second resistor connected in series; the output port of the AVDD boost circuit is connected to the signal input end of the boost chip after passing through the VCOM voltage divider subcircuit; the VCOM port of the boost chip is the output port of the VCOM boost circuit. The circuit diagram of the module boost module of the utility model is shown in FIG. Figure 1 shown.

[0032] Figure 1 Contains the circuit diagram of AVDD boost circuit, VGH boost circuit, VGL boost circuit, and VCOM boost circuit. Figure 1In the AVDD boost circuit, the energy storage inductor L2 is connected between the switch signal port SW port and the voltage input port VIN of the boost chip U2, and the SW port obtains the AVDD boost signal after passing through the diode D2. The voltage divider circuit includes a first AVDD resistor R1 and a second AVDD resistor R3 connected in series, one end of R1 is the AVDD boost signal, and the other end of R1 is grounded after passing through R3; the feedback port FB of U2 is connected between R1 and R3, and FB obtains the AVDD boost signal after passing through the filter capacitor C2; the AVDD boost signal is grounded after passing through the AVDD energy storage capacitor C1. The CTRL port of U2 is connected to the VIN port of U2. Both PGND ports of U2 are grounded.

[0033] Furthermore, the output voltage of the feedback port of the boost chip is divided by the AVDD voltage divider subcircuit to obtain the voltage output value of the AVDD boost circuit, that is, the voltage value of the AVDD boost signal is determined by the FB port voltage of U2 and the values ​​of R1 and R3. The expression of the AVDD boost signal is AVDD=V FB (1+R1 / R3), usually V FB The voltage value of is 1.146V, and the voltage range of the AVDD boost signal is less than or equal to 15V. In the utility model, the voltage value of the AVDD boost signal is 10.4V, R1 is 80.7KΩ, and R3 is 10KΩ.

[0034] The working process of the AVDD boost circuit is: SW is the switching signal of the AVDD boost circuit. When SW is the on signal, VIN charges the energy storage inductor L2 to store energy, and the diode D2 prevents the energy storage capacitor C1 from discharging to the ground; when SW is the off signal, since the inductor has the current holding characteristic, the current flowing through the energy storage inductor L2 will not immediately become 0, but slowly change from the current value when charging is completed to 0. During this current change process, the energy storage inductor L2 charges the energy storage capacitor C1 through the diode D2, so that the voltage across the energy storage capacitor C1 increases, and the AVDD boost signal is obtained.

[0035] exist Figure 1In the VGH boost circuit, a field effect tube port DRVP of U2 is connected to port 3 of VGH dual diode Q2 through VGH energy storage capacitor C10, port 1 of VGH dual diode is connected to AVDD boost signal, the boost signal is grounded through filter capacitor C14, port 2 of VGH dual diode is grounded through filter capacitor C16, port 2 is CPI signal, the CPI signal is also connected to CPI port of U2; port 2 is also grounded through VGH first resistor R4 and VGH second resistor R5, FBP port of U2 is connected between R4 and R5; SUP port of U2 is connected to AVDD boost signal, the output signal of VGH port of U2 is VGH boost signal. ADJ port signal of U2 is the control end of built-in shaping circuit, ADJ port is grounded after filter capacitor C13; DLY2 port of U2 is grounded after VGH filter capacitor C7, DLY2 port signal controls the power-on and power-off timing of VGH boost circuit and VGL boost circuit.

[0036] Furthermore, the output voltage of the FBP port of the boost chip is divided by the VGH voltage divider subcircuit to obtain the voltage output value of the VGH boost circuit, that is, the voltage value of the VGH boost signal is determined by the FBP port voltage of U2 and the resistance values ​​of R4 and R5.

[0037] VGH=V FBP (1+R4 / R5), in the present utility model, V FBP The value is 1.213V, the voltage range of the VGH boost signal is less than or equal to 30V, R4 is 115KΩ, and R5 is 10KΩ.

[0038] The working process of the VGH boost circuit is as follows: SUP uses the AVDD boost signal as the driving signal, and outputs a square wave signal with an amplitude of AVDD at the DRVP port through the built-in field effect tube of U2; when DRVP is in a low-level cycle, the AVDD boost signal charges the VGH energy storage capacitor C10 through the diode between the 1 port and the 3 port of Q2. After charging, the voltage on the right side of C10 is equal to the AVDD voltage; when DRVP is in a high-level cycle, because the voltage difference between the two capacitors cannot change suddenly, the voltage on the right side of the VGH energy storage capacitor C10 is raised to 2*AVDD. At this time, the diode between the 3 port and the 2 port of Q2 is turned on, and the 2*AVDD voltage is divided by R4 and R5 after passing through the diode to obtain the CPI signal; the CPI signal is input to the CPI port of U2, and the signal is internally shaped and outputs the VGH boost signal at the VGH port of U2.

[0039] exist Figure 1In the VGL boost circuit, the other FET DRVN port of U2 is connected to the 3rd port of the VGL dual diode through the VGL energy storage capacitor C11, the 2nd port of the VGL dual diode is grounded, the 1st port is grounded through the filter capacitor C15, the 1st port of the VGL dual diode is grounded after passing through the VGL first resistor R6 and the VGL second resistor R7, and then through the filter capacitor C18, and the voltage signal output by the 1st port of the VGL dual diode is the VGL boost signal. The DYL1 port of U2 is grounded after passing through the VGL filter capacitor C3; the FBN port of U2 is connected between R6 and R7; the REF port of U2 is connected between R7 and C18.

[0040] Furthermore, the output voltage of the FBN port of the boost chip is divided by the VGL voltage divider circuit to obtain the voltage output value of the VGL boost circuit. That is, the VGL boost signal is determined by the output voltage of the FBN port of U2, R6, and R7, VGL = V FBN (1+R6 / R7), where V FBN It is usually 1.213V. The output range of the VGL boost signal is usually less than or equal to -15V. In the present utility model, it is -9.9V. R6 is 82KΩ and R7 is 10KΩ.

[0041] The working process of the VGL boost circuit: SUP uses the AVDD boost signal as the driving signal, and outputs a square wave signal with an amplitude of AVDD at the DRVN port through another field effect tube built into U2; when DRVN is a high pulse cycle, the signal output by DRVN charges the VGL energy storage capacitor C11 through the 3rd and 2nd ports of the VGL dual diode Q1. After charging, the voltage value of the left end of C11 is AVDD; when DRVN is a low pulse 0 cycle, because the voltage difference on both sides of C11 cannot be imaged, the voltage on the right side of C11 is a negative voltage -AVDD relative to the left side. At this time, the 1st and 3rd ports of Q1 are turned on, and the -AVDD voltage is divided by R6 and R7 to obtain the VGL boost signal. Among them, the DLY1 port signal controls the power-on and power-off timing of AVDD and VGL.

[0042] exist Figure 1 In the VCOM boost circuit, the AVDD boost signal is grounded after passing through the VCOM first resistor R2 and the VCOM second resistor R8, the signal input terminal IN of U2 is connected between R2 and R8, IN is grounded through the filter capacitor C17, and the VCOM port of U2 outputs the VCOM boost signal. The VCOM port of U2 is grounded after passing through the filter capacitor C8.

[0043] Furthermore, the output voltage value of the AVDD boost circuit is divided by the VCOM voltage divider circuit to obtain the voltage output value of the VCOM boost circuit. That is, the VCOM boost signal is determined by the AVDD boost signal, R2, and R8. VCOM = V FBN (1+R2 / R8), wherein the voltage range of VCOM is less than or equal to 5 V. In the present invention, VCOM is 4 V, AVDD is 10.4 V, R2 is 12 KΩ, and R8 is 7.5 KΩ.

[0044] The working process of the VCOM boost circuit is as follows: the AVDD boost signal is input to the IN terminal of U2 after being divided by resistors R2 and R8. The voltage at the IN terminal is generated into a VCOM boost signal after passing through the VCOM buffer built into U2, and is output from the VCOM port of U2. The function of the VCOM buffer is to enhance the driving capability of the VCOM boost signal.

[0045] In addition, Figure 1 In the circuit, the FDLY port of U2 is connected to the VIN port of U2 through the filter capacitor C9; the COMP port of U2 is grounded through the filter capacitor C12;

[0046] Since the existing test board is unstable when outputting backlight, in order to ensure the smooth progress of the lighting test, the utility model also sets up a backlight boost module. The backlight boost module mainly includes a backlight boost chip, a backlight energy storage inductor, a backlight diode and a voltage divider resistor; the voltage input port of the backlight boost chip is connected to the control port; the voltage input port of the backlight boost chip obtains a switching signal after passing through the backlight energy storage inductor; the switching signal is connected to the switching port of the backlight boost chip, and the switching signal obtains a backlight anode signal after passing through the backlight diode; the feedback port of the backlight boost chip is grounded after passing through the voltage divider resistor; the signal output by the feedback port of the backlight boost chip is a backlight cathode signal.

[0047] exist Figure 2 In the backlight boost module, the voltage input port VIN of the backlight boost chip U1 is connected to the control port Ctrl, and the VIN signal enters VIN as the input voltage and enters Ctrl as the enable signal at the same time; the connection point of VIN and Ctrl obtains the switching signal SW1 after passing through the backlight energy storage inductor L1, and the switching signal SW1 is connected to the SW switching port of U1 and used as the switching signal of the backlight boost; the SW1 signal also obtains the backlight anode signal LEDA after passing through the backlight diode D1, and the LEDA is grounded after passing through the filter capacitor C4; the feedback port FB of U1 is grounded after passing through the resistor R9; the voltage signal of the FB port is the backlight cathode signal LEDK; the Comp port of U1 is grounded after passing through the filter capacitor C6, and the Comp port is the output end of the voltage error amplifier, which is used to stabilize the output voltage; the GND port of U1 is grounded.

[0048] Furthermore, the output current value of the backlight boost module is the quotient of the voltage value of the feedback port of the backlight boost chip and the voltage divider resistor, that is, ILED=V FB / R9. The backlight boost module is a constant current drive circuit, and the current range is usually less than or equal to 1.2A. FB The voltage is 0.2V, the current is 200mA, and R9 is 1Ω. The working process of the backlight boost module is similar to that of the AVDD boost circuit, and it also uses the current holding characteristics of the energy storage inductor to boost the voltage. Figure 1 The backlight boost module and Figure 2 The VIN signal in the module boost module is the same signal and is provided by the test board.

Claims

1. An expansion power supply device, characterized in that: Including module boost module; The module boost module includes a boost chip, an AVDD boost circuit, a VGH boost circuit, a VGL boost circuit and a VCOM boost circuit; the AVDD boost circuit, the VGH boost circuit, the VGL boost circuit and the VCOM boost circuit share the same boost chip; The AVDD boost circuit includes an energy storage inductor, a diode, an AVDD energy storage capacitor, a filter capacitor and an AVDD voltage divider sub-circuit; the energy storage inductor is connected between the switch signal port and the voltage input port of the boost chip; the switch signal port of the boost chip is used as the output port of the AVDD boost circuit after passing through the diode; the voltage divider sub-circuit includes a first AVDD resistor and a second AVDD resistor connected in series, one end of the first AVDD resistor is used as the output port of the AVDD boost circuit, and the other end of the first AVDD resistor is grounded after passing through the second AVDD resistor; the feedback port of the boost chip is connected between the first AVDD resistor and the second AVDD resistor, and the feedback port of the boost chip is also used as the output port of the AVDD boost circuit after passing through the filter capacitor; the output port of the AVDD boost circuit is grounded after passing through the AVDD energy storage capacitor; The VGH boost circuit mainly includes a VGH energy storage capacitor, a VGH double diode, a VGH filter capacitor and a VGH voltage divider sub-circuit; a field effect tube port of the boost chip is connected to the 3-port of the VGH double diode after passing through the VGH energy storage capacitor; the 1-port of the VGH double diode is connected to the output port of the AVDD boost circuit, and the 2-port of the VGH double diode is connected to the VGH voltage divider sub-circuit; the VGH voltage divider sub-circuit includes a VGH first resistor and a VGH second resistor connected in series, the 2-port of the VGH double diode is grounded after passing through the VGH first resistor and the VGH second resistor, and the 2-port of the VGH double diode is also connected to the CPI port of the boost chip; the FBP port of the boost chip is connected between the VGH first resistor and the VGH second resistor; the SUP port of the boost chip is connected to the output port of the AVDD boost circuit; the DLY2 end of the boost chip is grounded after passing through the VGH filter capacitor; the VGH port of the boost chip serves as the VGH boost circuit output port of the VGH boost circuit; The VGL boost circuit mainly includes a VGL energy storage capacitor, a VGL dual diode, a VGL voltage divider circuit, and a VGL filter capacitor; another field effect tube port of the boost chip is connected to port 3 of the VGL dual diode via the VGL energy storage capacitor; port 2 of the VGL dual diode is grounded, and port 1 of the VGL dual diode is connected to the VGL voltage divider circuit; the VGL voltage divider circuit includes a VGL first resistor and a VGL second resistor connected in series; port 1 of the VGL dual diode is grounded via the VGL first resistor and the VGL second resistor; port DLY1 of the boost chip is grounded via the VGL filter capacitor; port 1 of the VGL dual diode is the output port of the VGL boost circuit; The VCOM boost circuit mainly includes a VCOM voltage divider sub-circuit; the VCOM voltage divider sub-circuit includes a VCOM first resistor and a VCOM second resistor connected in series; the output port of the AVDD boost circuit is connected to the signal input end of the boost chip through the VCOM voltage divider sub-circuit; the VCOM port of the boost chip is the output port of the VCOM boost circuit.

2. The expansion power supply device according to claim 1, characterized in that: Also includes a backlight boost module; The backlight boost module mainly includes a backlight boost chip, a backlight energy storage inductor, a backlight diode and a voltage divider resistor; the voltage input port of the backlight boost chip is connected to the control port; the voltage input port of the backlight boost chip obtains a switching signal after passing through the backlight energy storage inductor; the switching signal is connected to the switching port of the backlight boost chip, and the switching signal obtains a backlight anode signal after passing through the backlight diode; the feedback port of the backlight boost chip is grounded after passing through the voltage divider resistor; The signal outputted by the feedback port of the backlight boost chip is a backlight cathode signal.

3. The expansion power supply device according to claim 1, characterized in that: The output voltage of the feedback port of the boost chip is divided by the AVDD voltage divider subcircuit to obtain a voltage output value of the AVDD boost circuit.

4. The expansion power supply device according to claim 1, characterized in that: The output voltage of the FBP port of the boost chip is divided by the VGH voltage divider subcircuit to obtain the voltage output value of the VGH boost circuit.

5. The expansion power supply device according to claim 1, characterized in that: The output voltage of the FBN port of the boost chip is divided by the VGL voltage divider sub-circuit to obtain the voltage output value of the VGL boost circuit.

6. The expansion power supply device according to claim 1, characterized in that: The output voltage value of the AVDD boost circuit is divided by the VCOM voltage divider subcircuit to obtain the voltage output value of the VCOM boost circuit.

7. The expansion power supply device according to claim 2, characterized in that: The output current value of the backlight boost module is the quotient of the voltage value of the feedback port of the backlight boost chip and the voltage dividing resistor.

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