VCOM generation circuit with temperature compensation function

Abstract

The invention discloses a VCOM generation circuit with a temperature compensation function, and relates to the technical field of electronics, and the circuit comprises a temperature sensitive module, a switch buck-boost module, a first capacitor and a second capacitor. The temperature sensitive module comprises a low-temperature compensation sub-module and a high-temperature compensation sub-module; the low-temperature compensation sub-module comprises a PTC thermistor and a first resistor which are connected in parallel; the high-temperature compensation submodule comprises an NTC thermistor and a second resistor which are connected in parallel; one end of the first resistor is connected in series with one end of the NTC thermistor, and the other end of the first resistor and a first connection node of a connection wire of the PTC thermistor are grounded; the other end of the PTC thermistor is connected in series with one end of the second resistor, and the first connection node is connected with the switch buck-boost module; and the switch buck-boost module is used for receiving a driving signal of the driving IC to realize temperature compensation.

Description

Technical Field

[0001] The present application relates to the field of electronic technology, and in particular to a VCOM generating circuit with a temperature compensation function. Background Art

[0002] The operating temperature of organic light-emitting diode (OLED) needs to cover -20 to 65 degrees Celsius, or even -40 to 85 degrees Celsius. However, since OLED microdisplays are greatly affected by ambient temperature, for commonly used constant voltage driven microdisplays, the brightness decreases at low temperatures and increases at high temperatures, affecting usage. Therefore, a temperature compensation function needs to be added.

[0003] Usually, the temperature compensation function is implemented in the driver integrated circuit (IC) of the OLED microdisplay or in an external controller. The method is as follows: 1. The sensor obtains the temperature and sends it to the processor; 2. The processor calculates the required VCOM voltage according to the built-in table or calculation formula; 3. The corresponding VCOM voltage is output to the VCOM generation circuit, and the VCOM generation circuit generates a VCOM voltage based on the temperature.

[0004] However, the above method has several disadvantages: 1. It requires internal or external processing resources of the IC; 2. The sensor accuracy is limited; 3. The refresh interval is long (20ms~1000ms) and is limited by the VCOM adjustment step, so flickering may occur during adjustment. Summary of the invention

[0005] The purpose of this application is to provide a VCOM generation circuit with temperature compensation function, which can achieve ultra-fast stepless temperature compensation by using the VCOM generation circuit on the external PCB backplane without IC revision. By setting the resistance to adjust the temperature compensation intensity, it can adapt to micro displays with different OLED device structures.

[0006] To achieve the above objectives, this application provides the following solutions.

[0007] In a first aspect, the present application provides a VCOM generating circuit with a temperature compensation function, including a temperature sensitive module, a switch buck-boost module, a first capacitor and a second capacitor.

[0008] The temperature sensitive module includes a low temperature compensation submodule and a high temperature compensation submodule; the low temperature compensation submodule includes a PTC thermistor and a first resistor connected in parallel; the high temperature compensation submodule includes an NTC thermistor and a second resistor connected in parallel; one end of the first resistor is connected in series with one end of the NTC thermistor, and the other end of the first resistor is grounded to a first connection node of a connecting wire of the PTC thermistor; the other end of the PTC thermistor is connected in series with one end of the second resistor, the other end of the second resistor is connected in series with a first capacitor, and the other end of the NTC thermistor is connected in series with a second capacitor.

[0009] The first connection node is connected to the switch buck-boost module; the switch buck-boost module is used to receive a driving signal from a driving IC.

[0010] Optionally, the switch buck-boost module includes a diode, a third capacitor, a first common-mode inductor coil, a second common-mode inductor coil, a third resistor and a field effect transistor; the cathode of the diode is connected to the first connection node; the anode of the diode and the second common-mode inductor coil and the third capacitor are connected to the second connection node; the other end of the second common-mode inductor coil is connected to the fourth connection node and the fifth connection node to output a common voltage VCOM_OUT; the common voltage VCOM_OUT is connected to the cathode of the OLED microdisplay; the fourth connection node is a point on the connecting wire between the NTC thermistor and the second capacitor; the fifth connection node is a point on the connecting wire between the second resistor and the first capacitor;

[0011] The other end of the third capacitor is connected to the drain of the field effect tube; the gate of the field effect tube is connected to the driving IC to receive the driving signal of the driving IC; the source of the field effect tube is grounded;

[0012] One end of the first coil of the common-mode inductor is connected to the third connection node, and the other end of the first coil of the common-mode inductor is connected to one end of the third resistor; the third connection node is a point on the wire connecting the third capacitor and the drain of the field effect transistor; the other end of the third resistor is connected to the positive power supply voltage.

[0013] Optionally, the sixth connection node is connected to the seventh connection node and generates a negative feedback voltage; the negative feedback voltage is used to feed back to the driver IC to adjust the drive signal; the sixth connection node is a point on the connecting wire between the PTC thermistor and the second resistor; the seventh connection node is a point on the connecting wire between the NTC thermistor and the first resistor.

[0014] Optionally, the other end of the first capacitor and the other end of the second capacitor are connected to an eighth connection node, and the eighth connection node is grounded for protection.

[0015] In a second aspect, the present application provides another VCOM generating circuit with a temperature compensation function, including a temperature compensation module, a switch buck-boost module, a first capacitor and a second capacitor.

[0016] The temperature compensation module includes a low temperature compensation submodule; the low temperature compensation submodule includes a PTC thermistor and a first resistor connected in parallel; the PTC thermistor and the first resistor are connected at a first connection node; the other end of the PTC thermistor is connected to the first capacitor; the other end of the first resistor is connected to the second capacitor.

[0017] The first connection node is connected to the switch buck-boost module; the switch buck-boost module is used to receive a driving signal from a driving IC.

[0018] Optionally, the switch buck-boost module includes a diode, a third capacitor, a first common-mode inductor coil, a second common-mode inductor coil, a third resistor and a field effect transistor; the cathode of the diode is connected to the first connection node; the anode of the diode and the second common-mode inductor coil and the third capacitor are connected to the second connection node; the other end of the second common-mode inductor coil is connected to the fourth connection node and the fifth connection node to output a common voltage VCOM_OUT; the common voltage VCOM_OUT is connected to the cathode of the OLED microdisplay; the fourth connection node is a point on the connecting wire between the first resistor and the second capacitor; the fifth connection node is a point on the connecting wire between the PTC thermistor and the first capacitor;

[0019] The other end of the third capacitor is connected to the drain of the field effect tube; the gate of the field effect tube is connected to the driving IC to receive the driving signal of the driving IC; the source of the field effect tube is grounded;

[0020] One end of the first coil of the common-mode inductor is connected to the third connection node, and the other end of the first coil of the common-mode inductor is connected to one end of the third resistor; the third connection node is a point on the wire connecting the third capacitor and the drain of the field effect transistor; the other end of the third resistor is connected to the positive power supply voltage.

[0021] In a third aspect, the present application provides another VCOM generating circuit with a temperature compensation function, including a temperature compensation module, a switch buck-boost module, a first capacitor and a second capacitor;

[0022] The temperature compensation module includes a high temperature compensation submodule; the high temperature compensation submodule includes an NTC thermistor and a second resistor connected in parallel; the NTC thermistor and the second resistor are connected to a first connection node; the other end of the NTC thermistor is connected to the second capacitor; the other end of the second resistor is connected to the first capacitor;

[0023] The first connection node is connected to the switch buck-boost module; the switch buck-boost module is used to receive a driving signal from a driving IC.

[0024] Optionally, the switch buck-boost module includes a diode, a third capacitor, a first common-mode inductor coil, a second common-mode inductor coil, a third resistor and a field effect transistor; the cathode of the diode is connected to the first connection node; the anode of the diode and the second common-mode inductor coil and the third capacitor are connected to the second connection node; the other end of the second common-mode inductor coil is connected to the fourth connection node and the fifth connection node to output a common voltage VCOM_OUT; the common voltage VCOM_OUT is connected to the cathode of the OLED microdisplay; the fourth connection node is a point on the connecting wire between the NTC thermistor and the second capacitor; the fifth connection node is a point on the connecting wire between the second resistor and the first capacitor;

[0025] The other end of the third capacitor is connected to the drain of the field effect tube; the gate of the field effect tube is connected to the driving IC to receive the driving signal of the driving IC; the source of the field effect tube is grounded;

[0026] One end of the first coil of the common-mode inductor is connected to the third connection node, and the other end of the first coil of the common-mode inductor is connected to one end of the third resistor; the third connection node is a point on the wire connecting the third capacitor and the drain of the field effect transistor; the other end of the third resistor is connected to the positive power supply voltage.

[0027] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0028] The present application provides a VCOM generating circuit with a temperature compensation function, which performs temperature compensation on the brightness of an OLED device through a temperature compensation module and a switch buck-boost module. The VCOM generating circuit on an external PCB backplane can be used to achieve ultra-fast stepless temperature compensation without revising the IC. The temperature compensation intensity can be adjusted by setting a first resistor and a second resistor, so that micro displays with different OLED device structures can be adapted. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 A schematic diagram of a VCOM generating circuit with a temperature compensation function provided by an embodiment of the present application;

[0031] Figure 2 A schematic diagram of a VCOM generating circuit with a temperature compensation function provided by another embodiment of the present application;

[0032] Figure 3 A schematic diagram of a VCOM generating circuit with a temperature compensation function provided by another embodiment of the present application;

[0033] Figure 4 A schematic diagram comparing the temperature compensation results of the present application and no compensation is provided for an embodiment of the present application. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0035] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0036] In an exemplary embodiment, Figure 1 As shown, a VCOM generating circuit with temperature compensation function is provided, including a temperature sensitive module, a switch buck-boost module, a first capacitor C1 and a second capacitor C2.

[0037] The temperature sensitive module includes a low temperature compensation submodule and a high temperature compensation submodule; the low temperature compensation submodule includes a PTC thermistor and a first resistor R1 connected in parallel; the high temperature compensation submodule includes an NTC thermistor and a second resistor R2 connected in parallel; one end of the first resistor R1 is connected in series with one end of the NTC thermistor, and the other end of the first resistor R1 is grounded to a first connection node A1 of a connecting wire of the PTC thermistor; the other end of the PTC thermistor is connected in series with one end of the second resistor R2, the other end of the second resistor R2 is connected in series with the first capacitor C1, and the other end of the NTC thermistor is connected in series with the second capacitor C2.

[0038] The other end of the first capacitor C1 and the other end of the second capacitor C2 are connected to an eighth connection node A8, and the eighth connection node A8 is grounded. Preferably, the first capacitor C1 can be 100nF, and the second capacitor C2 can be 10uF.

[0039] The first connection node A1 is connected to a switch buck-boost module, which is used to receive a drive signal VCOM_DRV of a driver IC. The drive signal VCOM_DRV can be obtained by pulse width modulation (PWM).

[0040] The switch buck-boost module is a Cuk circuit, including a diode D1, a third capacitor C3, a common-mode inductor first coil L1, a common-mode inductor second coil L2, a third resistor R3 and a field effect transistor Q1; the cathode of the diode D1 is connected to the first connection node A1; the anode of the diode D1 is connected to the common-mode inductor second coil L2 and the third capacitor C3 at the second connection node A2; the other end of the common-mode inductor second coil L2 is connected to the fourth connection node A4 and the fifth connection node A5, and a common voltage VCOM_OUT is output; the common voltage VCOM_OUT is connected to the cathode of the OLED microdisplay (OLED array); the fourth connection node A4 is a point on the connecting wire between the NTC thermistor and the second capacitor C2; the fifth connection node A5 is a point on the connecting wire between the second resistor R2 and the first capacitor C1.

[0041] In a specific example, the value range of the third capacitor C3 is 5 to 100 nF, the first common mode inductor coil L1 is 6.8 uH, and the second common mode inductor coil L2 is 6.8 uH. Optionally, in order to reduce the output ripple, the first common mode inductor coil L1 and the second common mode inductor coil L2 can be replaced by a common mode inductor, such as Figure 1 As shown, the first coil L1 of the common mode inductor and the second coil L2 of the common mode inductor are two coils on one common mode inductor. The resistance value of the third resistor R3 ranges from 0 to 10Ω.

[0042] The field effect transistor Q1 is an NMOS transistor. The other end of the third capacitor C3 is connected to the drain of the field effect transistor Q1. The gate of the field effect transistor Q1 is connected to the driver IC to receive the driving signal VCOM_DRV of the driver IC. The source of the field effect transistor Q1 is grounded.

[0043] One end of the common-mode inductor first coil L1 is connected to the third connection node A3, and the other end of the common-mode inductor first coil L1 is connected to one end of the third resistor R3; the third connection node A3 is a point on the wire connecting the third capacitor C3 and the drain of the field effect transistor Q1; the other end of the third resistor R3 is connected to the positive power supply voltage VDD.

[0044] The sixth connection node A6 is connected to the seventh connection node A7, and generates a negative feedback voltage VCOM_FB; the negative feedback voltage VCOM_FB is used to feed back to the driver IC to adjust the drive signal VCOM_DRV. Specifically, the negative feedback voltage VCOM_FB is used to monitor the change of the common voltage VCOM_OUT and feed back to the driver IC to adjust the drive signal VCOM_DRV to adapt to the load change. The sixth connection node A6 is a point on the connecting wire between the PTC thermistor and the second resistor R2; the seventh connection node A7 is a point on the connecting wire between the NTC thermistor and the first resistor R1.

[0045] The present application realizes its sensitivity to temperature through a switch buck-boost module (Cuk circuit, i.e., a switch buck-boost circuit) and a temperature compensation module. The temperature compensation module is a resistor network with specific temperature sensitivity.

[0046] The temperature coefficient of the NTC thermistor is too steep compared to that of the OLED device. A second resistor R2 with a smaller resistance is added to adjust the temperature compensation intensity and adapt to different OLED device structures (OLEDs with different structures / light colors have different temperature coefficients); the first resistor R1 is used to correct the resistance value of the PTC thermistor for matching the circuit.

[0047] The NTC thermistor has a negative temperature coefficient, the PTC thermistor has a positive temperature coefficient, and the negative feedback voltage VCOM_FB remains unchanged. Therefore, the lower the temperature, the higher the voltage on the common voltage VCOM_OUT, which keeps the brightness of the OLED device stable and realizes the temperature compensation function.

[0048] The NTC thermistor is connected in parallel with the second resistor R2 and then in series with the first resistor R1 to form a voltage divider circuit. At this time, the relationship between the feedback voltage VCOM_FB and the common voltage VCOM_OUT is shown in the following formula.

[0049]

[0050] In the formula, R1 is the resistance value of the first resistor R1, R2 is the resistance value of the second resistor R2, Rptc represents the resistance value of the PTC thermistor, and Rntc represents the resistance value of the NTC thermistor.

[0051] The drive signal VCOM_DRV input controls the on and off of the field effect tube Q1. The drive process is divided into two stages:

[0052] In the first stage, when the field effect tube Q1 is turned on: the input power supply (positive power supply voltage VDD) charges the first coil L1 of the common mode inductor through the field effect tube Q1, and the first capacitor C1 provides power to the output through the second coil L2 of the common mode inductor. The current I L1 The voltage of the third capacitor C3 increases, and the third capacitor C3 discharges and stores excess electrical energy in the second coil L2 of the common mode inductor.

[0053] In the second stage, when the field effect tube Q1 is turned off: the input power supply (positive power supply voltage VDD) and the first coil of the common mode inductor L1 jointly charge the third capacitor (energy storage capacitor) C3. The second coil of the common mode inductor L2 transfers electrical energy to the load (i.e., the temperature compensation module) through the diode D1 to achieve energy transfer and output.

[0054] The output voltage of the switch buck-boost module feeds back the negative feedback voltage VCOM_FB to the driver IC chip after passing through the temperature compensation module. The driver IC chip adjusts the time ratio between the first stage and the second stage by comparing the negative feedback voltage VCOM_FB with the preset value, so that the negative feedback voltage VCOM_FB is equal to the preset value, thereby achieving a stable common voltage VCOM_OUT output.

[0055] In actual application, since one of the PTC thermistor and the NTC thermistor can be removed according to the situation to save costs, when it is mainly used to compensate for the brightness at high temperatures, the PTC thermistor can be omitted; when it is mainly used to compensate for the brightness at low temperatures, the NTC thermistor can be omitted.

[0056] In another exemplary embodiment of the present application, Figure 2 As shown, a VCOM generating circuit with temperature compensation function is provided, including a temperature compensation module, a switch buck-boost module, a first capacitor C1 and a second capacitor C2.

[0057] The temperature compensation module includes a low temperature compensation submodule; the temperature compensation module includes a low temperature compensation submodule; the low temperature compensation submodule includes a PTC thermistor and a first resistor R1 connected in parallel; the PTC thermistor and the first resistor R1 are connected to a first connection node A1; the other end of the PTC thermistor is connected to a first capacitor C1; the other end of the first resistor R1 is connected to a second capacitor C2.

[0058] The first connection node A1 is connected to the switch buck-boost module; the switch buck-boost module is used to receive the driving signal VCOM_DRV of the driving IC.

[0059] like Figure 2 The VCOM generation circuit with temperature compensation function shown is used to compensate for low temperature.

[0060] The switch buck-boost module includes a diode D1, a third capacitor C3, a common-mode inductor first coil L1, a common-mode inductor second coil L2, a third resistor R3 and a field effect transistor Q1; the cathode of the diode D1 is connected to the first connection node A1; the anode of the diode D1 is connected to the common-mode inductor second coil L2 and the third capacitor C3 at the second connection node A2; the other end of the common-mode inductor second coil L2 is connected to the fourth connection node A4 and the fifth connection node A5, and a common voltage VCOM_OUT is output; the common voltage VCOM_OUT is connected to the cathode of the OLED microdisplay; the fourth connection node A4 is a point on the connecting wire between the first resistor R1 and the second capacitor C2; the fifth connection node A5 is a point on the connecting wire between the PTC thermistor and the first capacitor C1.

[0061] The other end of the third capacitor C3 is connected to the drain of the field effect transistor Q1; the gate of the field effect transistor Q1 is connected to the driving IC for receiving the driving signal VCOM_DRV of the driving IC; the source of the field effect transistor Q1 is grounded.

[0062] One end of the common-mode inductor first coil L1 is connected to the third connection node A3, and the other end of the common-mode inductor first coil L1 is connected to one end of the third resistor R3; the third connection node A3 is a point on the wire connecting the third capacitor C3 and the drain of the field effect transistor Q1; the other end of the third resistor R3 is connected to the positive power supply voltage VDD.

[0063] In another exemplary embodiment of the present application, Figure 3 As shown, a VCOM generating circuit with temperature compensation function is provided, including a temperature compensation module, a switch buck-boost module, a first capacitor C1 and a second capacitor C2.

[0064] The temperature compensation module includes a high temperature compensation submodule; the temperature compensation module includes a high temperature compensation submodule; the high temperature compensation submodule includes an NTC thermistor and a second resistor R2 connected in parallel; the NTC thermistor and the second resistor R2 are connected to a first connection node A1; the other end of the NTC thermistor is connected to the second capacitor C2; the other end of the second resistor R2 is connected to the first capacitor C1.

[0065] The first connection node A1 is connected to the switch buck-boost module; the switch buck-boost module is used to receive the driving signal VCOM_DRV of the driving IC.

[0066] like Figure 3 The VCOM generating circuit with temperature compensation function shown is used to compensate for high temperature.

[0067] The switch buck-boost module includes a diode D1, a third capacitor C3, a common-mode inductor first coil L1, a common-mode inductor second coil L2, a third resistor R3 and a field effect transistor Q1; the cathode of the diode D1 is connected to the first connection node A1; the anode of the diode D1 is connected to the common-mode inductor second coil L2 and the third capacitor C3 at the second connection node A2; the other end of the common-mode inductor second coil L2 is connected to the fourth connection node A4 and the fifth connection node A5, and a common voltage VCOM_OUT is output; the common voltage VCOM_OUT is connected to the cathode of the OLED microdisplay; the fourth connection node A4 is a point on the connecting wire between the NTC thermistor and the second capacitor C2; the fifth connection node A5 is a point on the connecting wire between the second resistor R2 and the first capacitor C1.

[0068] The other end of the third capacitor C3 is connected to the drain of the field effect transistor Q1; the gate of the field effect transistor Q1 is connected to the driving IC for receiving the driving signal VCOM_DRV of the driving IC; the source of the field effect transistor Q1 is grounded.

[0069] One end of the common-mode inductor first coil L1 is connected to the third connection node A3, and the other end of the common-mode inductor first coil L1 is connected to one end of the third resistor R3; the third connection node A3 is a point on the wire connecting the third capacitor C3 and the drain of the field effect transistor Q1; the other end of the third resistor R3 is connected to the positive power supply voltage VDD.

[0070] The resistance and VCOM output results at different temperatures are shown in Table 1. The comparison results of the VCOM generation circuit with temperature compensation function provided by the present application and the temperature compensation without compensation are shown in Table 1. Figure 4 shown.

[0071] Regarding the parameters adapted for the existing stacked white light OLED, as an optional implementation, the NTC thermistor is selected to be 10kΩ@25℃, with an exponential temperature coefficient; the PTC thermistor is selected to be 10kΩ linear PTC, with a relatively linear temperature coefficient of 6000ppm / K; the resistance values ​​of the first resistor R1 and the second resistor R2 can be 10kΩ.

[0072] Table 1 Resistance value and common voltage VCOM_OUT output results at different temperatures

[0073]

[0074]

[0075] From Table 1 and Figure 4It can be seen that the brightness stability of the VCOM generating circuit with temperature compensation function provided by the present application is significantly improved.

[0076] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, 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.

[0077] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A VCOM generating circuit with temperature compensation function, characterized in that: The VCOM generating circuit with temperature compensation function includes a temperature sensitive module, a switch buck-boost module, a first capacitor and a second capacitor; The temperature sensitive module includes a low temperature compensation submodule and a high temperature compensation submodule; the low temperature compensation submodule includes a PTC thermistor and a first resistor connected in parallel; the high temperature compensation submodule includes an NTC thermistor and a second resistor connected in parallel; one end of the first resistor is connected in series with one end of the NTC thermistor, and the other end of the first resistor is grounded to a first connection node of a connecting wire of the PTC thermistor; the other end of the PTC thermistor is connected in series with one end of the second resistor, the other end of the second resistor is connected in series with a first capacitor, and the other end of the NTC thermistor is connected in series with a second capacitor; The first connection node is connected to the switch buck-boost module; the switch buck-boost module is used to receive a driving signal from a driving IC.

2. The VCOM generating circuit with temperature compensation function according to claim 1, characterized in that: The switch buck-boost module includes a diode, a third capacitor, a first common-mode inductor coil, a second common-mode inductor coil, a third resistor and a field effect transistor; the cathode of the diode is connected to the first connection node; the anode of the diode is connected to the second common-mode inductor coil and the third capacitor at the second connection node; the other end of the second common-mode inductor coil is connected to the fourth connection node and the fifth connection node to output a common voltage VCOM_OUT; the common voltage VCOM_OUT is connected to the cathode of the OLED micro display; the fourth connection node is a point on the connecting wire between the NTC thermistor and the second capacitor; the fifth connection node is a point on the connecting wire between the second resistor and the first capacitor; The other end of the third capacitor is connected to the drain of the field effect tube; the gate of the field effect tube is connected to the driving IC to receive the driving signal of the driving IC; The source of the field effect tube is grounded; One end of the first coil of the common-mode inductor is connected to the third connection node, and the other end of the first coil of the common-mode inductor is connected to one end of the third resistor; the third connection node is a point on the wire connecting the third capacitor and the drain of the field effect transistor; the other end of the third resistor is connected to the positive power supply voltage.

3. The VCOM generating circuit with temperature compensation function according to claim 1, characterized in that: The sixth connection node is connected to the seventh connection node and generates a negative feedback voltage; the negative feedback voltage is used to feed back to the driver IC to adjust the drive signal; the sixth connection node is a point on the connecting wire between the PTC thermistor and the second resistor; the seventh connection node is a point on the connecting wire between the NTC thermistor and the first resistor.

4. The VCOM generating circuit with temperature compensation function according to claim 1, characterized in that: The other end of the first capacitor and the other end of the second capacitor are connected to an eighth connection node, and the eighth connection node is grounded for protection.

5. A VCOM generating circuit with temperature compensation function, characterized in that: The VCOM generating circuit with temperature compensation function comprises a temperature compensation module, a switch buck-boost module, a first capacitor and a second capacitor; The temperature compensation module includes a low temperature compensation submodule; the temperature compensation module includes a low temperature compensation submodule; the low temperature compensation submodule includes a PTC thermistor and a first resistor connected in parallel; the PTC thermistor and the first resistor are connected to a first connection node; the other end of the PTC thermistor is connected to the first capacitor; the other end of the first resistor is connected to the second capacitor; The first connection node is connected to the switch buck-boost module; the switch buck-boost module is used to receive a driving signal from a driving IC.

6. The VCOM generating circuit with temperature compensation function according to claim 5, characterized in that: The switch buck-boost module includes a diode, a third capacitor, a first common-mode inductor coil, a second common-mode inductor coil, a third resistor and a field effect transistor; the cathode of the diode is connected to the first connection node; the anode of the diode is connected to the second common-mode inductor coil and the third capacitor at the second connection node; the other end of the second common-mode inductor coil is connected to the fourth connection node and the fifth connection node to output a common voltage VCOM_OUT; the common voltage VCOM_OUT is connected to the cathode of the OLED microdisplay; the fourth connection node is a point on the connecting wire between the first resistor and the second capacitor; the fifth connection node is a point on the connecting wire between the PTC thermistor and the first capacitor; The other end of the third capacitor is connected to the drain of the field effect tube; the gate of the field effect tube is connected to the driving IC to receive the driving signal of the driving IC; The source of the field effect tube is grounded; One end of the first coil of the common-mode inductor is connected to the third connection node, and the other end of the first coil of the common-mode inductor is connected to one end of the third resistor; the third connection node is a point on the wire connecting the third capacitor and the drain of the field effect transistor; the other end of the third resistor is connected to the positive power supply voltage.

7. A VCOM generating circuit with temperature compensation function, characterized in that: The VCOM generating circuit with temperature compensation function comprises a temperature compensation module, a switch buck-boost module, a first capacitor and a second capacitor; The temperature compensation module includes a high temperature compensation submodule; the temperature compensation module includes a high temperature compensation submodule; the high temperature compensation submodule includes an NTC thermistor and a second resistor connected in parallel; the NTC thermistor and the second resistor are connected to a first connection node; the other end of the NTC thermistor is connected to the second capacitor; the other end of the second resistor is connected to the first capacitor; The first connection node is connected to the switch buck-boost module; the switch buck-boost module is used to receive a driving signal from a driving IC.

8. The VCOM generating circuit with temperature compensation function according to claim 7, characterized in that: The switch buck-boost module includes a diode, a third capacitor, a first common-mode inductor coil, a second common-mode inductor coil, a third resistor and a field effect transistor; the cathode of the diode is connected to the first connection node; the anode of the diode and the second common-mode inductor coil and the third capacitor are connected to the second connection node; the other end of the second common-mode inductor coil is connected to the fourth connection node and the fifth connection node to output a common voltage VCOM_OUT; the common voltage VCOM_OUT is connected to the cathode of the OLED micro display; the fourth connection node is a point on the connecting wire between the NTC thermistor and the second capacitor; The fifth connection node is a point on the connecting wire between the second resistor and the first capacitor; The other end of the third capacitor is connected to the drain of the field effect tube; the gate of the field effect tube is connected to the driving IC to receive the driving signal of the driving IC; The source of the field effect tube is grounded; One end of the first coil of the common-mode inductor is connected to the third connection node, and the other end of the first coil of the common-mode inductor is connected to one end of the third resistor; the third connection node is a point on the wire connecting the third capacitor and the drain of the field effect transistor; the other end of the third resistor is connected to the positive power supply voltage.

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