CN111277134A - Voltage conversion circuit and display device - Google Patents

Abstract

The present invention provides a voltage conversion circuit and a display device, belonging to the technical field of display, which can solve the problems that the output voltage of the existing voltage conversion circuit has a low adjustment range and low adjustment accuracy. The voltage conversion circuit of the present invention includes: a conversion unit for converting an input voltage into an output voltage and outputting; a regulating unit for generating a regulating voltage according to a control command; a feedback unit for converting the output voltage and the regulating voltage according to the The pre-output voltage is generated and fed back to the conversion unit, so that the conversion unit adjusts the pre-output voltage according to the reference voltage to obtain the adjusted output voltage for output.

Description

Voltage conversion circuit and display device

technical field

The invention belongs to the technical field of display, and in particular relates to a voltage conversion circuit and a display device.

Background technique

The DC/DC DC voltage conversion circuit (Direct current-Direct current converter) is a voltage conversion circuit that converts a DC high voltage (low voltage) into a DC low voltage (high voltage).

The inventor found that there are at least the following problems in the prior art: the output voltage converted by the DC/DC DC voltage conversion circuit is generally a fixed voltage value or the voltage value of the output voltage needs to be manually adjusted, so the DC/DC in the prior art The adjustment range of the output voltage of the DC voltage conversion circuit is low, and the adjustment precision is low, which cannot meet the requirements for the output voltage in the display device.

SUMMARY OF THE INVENTION

The present invention aims to solve at least one of the technical problems existing in the prior art, and provides a voltage conversion circuit and a display device.

The technical solution adopted to solve the technical problem of the present invention is a voltage conversion circuit, including:

The conversion unit is used to convert the input voltage into the output voltage and output it;

an adjustment unit, used for generating an adjustment voltage according to the control instruction;

a feedback unit, configured to generate a pre-output voltage according to the output voltage and the adjustment voltage, and feed it back to the conversion unit, so that the conversion unit adjusts the pre-output voltage according to the reference voltage, and obtains the adjusted output voltage for output.

Optionally, the adjustment unit includes: a controller and a digital-to-analog converter;

The controller is connected to the digital-to-analog converter, for generating a digital signal according to the control instruction, and inputting the digital signal to the digital-to-analog converter;

The digital-to-analog converter is connected to the feedback unit for converting the digital signal into an regulated voltage, and inputting the regulated voltage into the feedback unit.

Optionally, the feedback unit includes: a first resistor and a second resistor;

One end of the first resistor is connected to the conversion unit and the power supply voltage output end, and the other end is connected to the conversion unit and one end of the second resistor;

One end of the second resistor is connected to the other end of the first resistor and the conversion unit, and the other end is connected to the digital-to-analog converter.

Optionally, the voltage conversion circuit further includes: a first filtering unit;

The first filtering unit is used for filtering the input voltage.

Optionally, the first filtering unit includes: a first capacitor;

One end of the first capacitor is connected to the power supply voltage input end and the conversion unit, and the other end is connected to the conversion unit and grounded.

Optionally, the voltage conversion circuit further includes: a second filtering unit;

The second filtering unit is used for filtering the output voltage.

Optionally, the second filtering unit includes: an inductor and a second capacitor;

One end of the inductor is connected to the conversion unit, and the other end is connected to one end of the first resistor, one end of the second capacitor and the power supply voltage output end;

One end of the second capacitor is connected to the other end of the inductor, one end of the first resistor and the power supply voltage output end.

Optionally, the conversion unit includes a conversion chip; the conversion chip has: an input terminal, an enabling terminal, a ground terminal, an output terminal and a feedback terminal; the input terminal is short-circuited with the enabling terminal and connected to the A power supply voltage input terminal, the ground terminal is grounded, the output terminal is connected to one end of the inductor, and the feedback terminal is connected to the other end of the first resistor and one end of the second resistor.

Optionally, the conversion chip includes: a startup module, a conversion module, a comparison module and a reference voltage module;

The control signal input terminal of the startup module is used as the enabling terminal;

The voltage input terminal and the voltage output terminal of the conversion module are used as the input terminal and the output terminal, respectively;

The positive input terminal of the comparison module is used as the feedback terminal, the negative input terminal is connected to the reference voltage module, and the signal output terminal is connected to the conversion module.

The technical solution adopted to solve the technical problem of the present invention is a voltage conversion circuit, comprising: a first capacitor, a second capacitor, a conversion chip, an inductor, a first resistor, a second resistor, a controller and a digital-to-analog converter; the The conversion chip has an input terminal, an enabling terminal, a ground terminal, an output terminal and a feedback terminal;

One end of the first capacitor is connected to the power supply voltage input end, the input end and the enabling end, and the other end is connected to the ground end and grounded;

The input terminal of the conversion chip is short-circuited with the enabling terminal and connected to the power supply voltage input terminal and one end of the first capacitor, and the ground terminal is connected to the other end of the first capacitor and grounded, the output end is connected to one end of the inductor, the feedback end is connected to the other end of the first resistor and one end of the second resistor;

One end of the inductor is connected to the output end, and the other end is connected to one end of the first resistor, one end of the second capacitor and the power supply voltage output end;

One end of the second capacitor is connected to the other end of the inductor, one end of the first resistor and the power supply voltage output end;

One end of the first resistor is connected to the other end of the inductor, one end of the second capacitor and the power supply voltage output end, and the other end is connected to the feedback end and one end of the second resistor;

One end of the second resistor is connected to the other end of the first resistor and the feedback end, and the other end is connected to the digital-to-analog converter;

the controller is connected to the digital-to-analog converter;

The digital-to-analog converter is connected to the other end of the second resistor.

The technical solution adopted to solve the technical problem of the present invention is a display device including the above-mentioned voltage conversion circuit.

Description of drawings

1 and FIG. 3 are schematic structural diagrams of a voltage conversion circuit according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of an implementation principle of a voltage conversion circuit provided by an embodiment of the present invention.

The reference numerals are: 101-conversion unit, 102-adjustment unit, 103-feedback unit, 104-first filtering unit, 105-second filtering unit, 1021-controller, 1022-digital-to-analog converter, Vin1-power supply Voltage input terminal, Vout1-power supply voltage output terminal, R1-first resistor, R2-second resistor, C1-first capacitor, L-inductor, C2-second capacitor, Vin2-input terminal, EN-enable terminal, GND-ground terminal, Vout2-output terminal, and FB-feedback terminal.

Detailed ways

In order to make those skilled in the art better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

Example 1

FIG. 1 is a schematic structural diagram of a voltage conversion circuit according to an embodiment of the present invention. As shown in FIG. 1 , the voltage conversion circuit includes a conversion unit 101 , an adjustment unit 102 and a feedback unit 103 . The conversion unit 101 is used to convert the input voltage into an output voltage and output it. The adjustment unit 102 is configured to generate an adjustment voltage according to the control instruction. The feedback unit 103 is configured to generate a pre-output voltage according to the output voltage and the adjustment voltage, and feed it back to the conversion unit 101, so that the conversion unit 101 adjusts the pre-output voltage according to the reference voltage to obtain the adjusted output voltage for output.

In the voltage conversion circuit provided by the embodiment of the present invention, the input voltage can be input to the conversion unit 101 through the power supply voltage input terminal Vin1, and the conversion unit 101 can convert the input voltage into an output voltage, and the output voltage can be a pulse voltage with a certain amplitude. , can also be further converted into DC voltage to provide power supply voltage for other components. The adjustment unit 102 may generate the adjustment voltage according to the control instruction. The feedback unit 103 may generate a pre-output voltage according to the output voltage of the power supply voltage output terminal Vout1 and the regulation voltage generated by the regulation unit 102 , and feed back the pre-output voltage to the conversion unit 101 . After receiving the pre-output voltage, the conversion unit 101 may adjust the pre-output voltage according to the reference voltage, and output the adjusted output voltage. In this way, on the basis of the original voltage conversion circuit, it is only necessary to use the adjustment unit 102 to apply the adjustment voltage to the conversion unit 101 through the feedback unit 103, so that the output voltage of the conversion unit 101 can be adjusted without adding other additional components. Therefore, the complexity of adjusting the voltage in the existing voltage conversion circuit can be simplified, so that the reliability of the circuit can be improved, and the circuit design and manufacturing cost can be saved.

Optionally, the adjustment unit 102 includes: a controller 1021 and a digital-to-analog converter 1022; the controller 1021 is connected to the digital-to-analog converter 1022, for generating a digital signal according to the control instruction, and inputting the digital signal into the digital-to-analog converter; the digital-to-analog converter; The converter 1022 is connected to the feedback unit 103 for converting the digital signal into an regulated voltage, and inputting the regulated voltage to the feedback unit.

It should be noted that the adjustment unit 102 may be specifically composed of a digital-to-analog converter 1022 controlled by the controller 1021 . The controller 1021 can be a microcontroller (Microcontroller Unit, MCU) or a central processing unit (Central Processing Unit, CPU), and can be connected to a digital-to-analog converter through a serial peripheral interface (Serial Peripheral Interface, SPI) or other busses 1022 connection, in this embodiment of the present invention, the MCU may be the first choice. The user can input control instructions to the controller 1021 according to actual needs. The controller 1021 can generate a digital signal according to the control instruction input by the user, and input the digital signal to the digital-to-analog converter 1022 . The digital-to-analog converter 1022 can convert the digital signal input by the controller 1021 into an analog signal that can be recognized by the voltage conversion circuit, that is, the regulated voltage, and input the regulated voltage into the feedback unit 103, so that the conversion unit 101 can adjust the voltage to the reference voltage according to the reference voltage. The pre-output voltage is adjusted to obtain the adjusted output voltage and output. It can be understood that, in this embodiment of the present invention, the adjustment unit 102 may also be composed of a pulse width modulation circuit (Pulse Width Modulation, PWM) or an R-2R resistor network, and its implementation principle is similar to the above-mentioned implementation principle, which is not repeated here. Repeat.

Optionally, the feedback unit 103 includes: a first resistor R1 and a second resistor R2. One end of the first resistor R1 is connected to the conversion unit 101 and the power supply voltage output terminal Vout1, and the other end is connected to the conversion unit 101 and one end of the second resistor R2; one end of the second resistor R2 is connected to the other end of the first resistor R1 and the conversion unit 101, The other end is connected to the digital-to-analog converter 1022 .

It should be noted that, according to the principle of voltage superposition, the pre-output voltage Vfb of the input conversion unit 101 can be decomposed into the adjustment voltage Vdac and the output voltage Vout1. When applied to the circuit respectively, the pre-output voltage Vfb can be the sum of Vfb1 and Vfb2. As shown in FIG. 2 , the pre-output voltage Vfb can be: Vfb=Vfb1+Vfb2=Vout1R2/(R1+R2)+VdacR1/(R1+R2), thus, Vout1=(Vfb(R1+R2)- VdacR1)/R2, it can be seen from the above that the factors affecting the output voltage Vout1 are not only the resistance values of the first resistor R1 and the second resistor R2 in the feedback unit 103, but also the adjustment voltage Vdac output by the adjustment unit 102, so that , the adjustment of the output voltage Vout1 in the voltage conversion circuit can be achieved by changing the adjustment voltage Vdac output by the adjustment unit 102, and other additional components do not need to be added to the entire circuit, so the complexity of voltage adjustment in the existing voltage conversion circuit can be simplified. , so that the reliability of the circuit can be improved, and the cost of circuit design and fabrication can be saved.

For the adjustment range of the output voltage Vout1, when Vdac is 0, the entire voltage conversion circuit can reach the maximum output voltage, namely Vfb(R1+R2)/R2; when Vdac is Vfb(R1+R2)/R1, the entire voltage conversion circuit The circuit can reach a minimum output voltage of 0V. In practical applications, if the influence of the output resistance Rout of the digital-to-analog converter 1022 on the entire circuit is considered, then Vout1=(Vfb(R1+R2+Rout)−VdacR1)/(R2+Rout), then the maximum output voltage is Vfb (R1+R2+Rout)/(R2+Rout), the minimum output voltage is 0V. Therefore, the voltage conversion circuit provided by the embodiment of the present invention can realize a larger voltage adjustment range.

For the adjustment accuracy of the output voltage Vout1, regardless of the influence of temperature, resistance accuracy and other factors on the circuit, assuming that the step voltage of Vdac is Vstep, then the step voltage of Vout1 is Vstep·R1/R2. For mature digital-to-analog converters It's very easy to get to 16 bits. Assuming that the precision of the digital-to-analog converter in the effective output range is 14bit, the maximum output voltage Vout1 of the voltage conversion circuit is 24 volts (V), and the pre-output voltage Vfb is 1.25V, then R1/R2=18.2, in this case, Vout The step voltage is 18.2·Vstep, that is, the output accuracy of about 10bit is achieved. If this accuracy cannot meet the actual demand, it is only necessary to improve the accuracy of the digital-to-analog converter to increase the accuracy of the output voltage Vout1 accordingly. Therefore, the voltage conversion circuit provided by the embodiment of the present invention can realize precise adjustment of the output voltage Vout1.

Optionally, the voltage conversion circuit further includes: a first filtering unit 104 . The first filtering unit 104 is used for filtering the input voltage.

It should be noted that the first filtering unit 104 can filter the voltage input from the power supply voltage input terminal Vin1, and can filter the voltage input from the power supply voltage input terminal Vin1 that may cause interference to the conversion unit 101, so as to reduce the input voltage. The interference of the voltage on the performance of the conversion unit 101 .

Optionally, the first filtering unit 104 includes: a first capacitor C1. One end of the first capacitor C1 is connected to the power supply voltage input terminal Vin1 and the conversion unit 101 , and the other end is connected to the conversion unit 101 and grounded.

It should be noted that, in practical applications, the first filter unit 104 may include a first capacitor C1. Due to the characteristics of the capacitor, the first capacitor C1 may filter the AC voltage part of the input voltage, thereby reducing the impact on the performance of the conversion unit 101. interference.

Optionally, the voltage conversion circuit further includes: a second filtering unit 105 . The second filtering unit 102 is used for filtering the output voltage.

It should be noted that the conversion unit 101 can convert the input voltage into an output voltage, and the output voltage can be a pulse voltage with a certain amplitude, and the second filter unit 105 can filter the pulse voltage and filter the interference voltage in the pulse voltage. filter to form the required DC voltage.

Optionally, the second filtering unit 105 includes: an inductor L and a second capacitor C2. One end of the inductor L is connected to the conversion unit 101, and the other end is connected to one end of the first resistor R1, one end of the second capacitor C2 and the power supply voltage output end Vout1; one end of the second capacitor C2 is connected to the other end of the inductor L, the first resistor R1 One terminal and the power supply voltage output terminal Vout1.

It should be noted that the inductor L and the second capacitor C2 can form an LC resonance circuit, which can separate the required DC voltage from the pulse voltage, so that the DC voltage can be output through the power supply voltage output terminal Vout1, and then the DC voltage can be used for other Components provide supply voltage.

Optionally, the conversion unit 101 includes a conversion chip; the conversion chip has: an input terminal Vin2, an enabling terminal EN, a ground terminal GND, an output terminal Vout2 and a feedback terminal FB; the input terminal Vin2 is short-circuited with the enabling terminal EN and connected to the power supply voltage The input terminal Vin1, the ground terminal GND is grounded, the output terminal Vout2 is connected to one end of the inductor L, and the feedback terminal FB is connected to the other end of the first resistor R1 and one end of the second resistor R2.

It should be noted that the conversion chip can convert the input voltage to the output voltage, and adjust the output voltage according to the voltage of the feedback terminal FB. When the output voltage in the voltage conversion circuit does not need to be adjusted, the voltage of the feedback terminal FB of the conversion chip is generally equal to the reference voltage, and the output voltage is a constant value. When the output voltage needs to be adjusted, the output voltage and the adjusted voltage can be input to the feedback terminal FB through the first resistor R1 and the second resistor R2, and the output voltage can be precisely adjusted according to the reference voltage.

Optionally, the conversion chip includes: a start-up module, a conversion module, a comparison module and a reference voltage module; the control signal input end of the start-up module is used as the enable terminal EN; the voltage input end and the voltage output end of the conversion module are respectively used for the input end Vin2 and the output terminal Vout2; the positive input terminal of the comparison module is used as the feedback terminal FB, the negative input terminal is connected to the reference voltage module, and the signal output terminal is connected to the conversion module.

It should be noted that the start-up module can control the conversion chip to start and work when the start-up voltage is input to the control signal input terminal. The conversion module can convert the input voltage into an output voltage, and the output voltage can have a pulse voltage with a certain amplitude. The comparison module can compare the pre-output voltage formed by the output voltage and the regulated voltage with the reference voltage provided by the reference voltage module, generate the pre-output voltage according to the reference voltage, and feed it back to the conversion module. The reference voltage module can provide a reference voltage for the comparison module. The reference voltage can be 1.2V or other voltage values. The voltage value of the reference voltage can be set according to actual needs, which will not be listed here.

Embodiment 2

3 is a voltage conversion circuit provided by an embodiment of the present invention. The voltage conversion circuit includes: a first capacitor C1, a second capacitor C2, a conversion chip, an inductor L, a first resistor R1, a second resistor R2, and a controller 1021 and a digital-to-analog converter 1022; the conversion chip has an input terminal Vin2, an enable terminal EN, a ground terminal GND, an output terminal Vout2 and a feedback terminal FB.

One end of the first capacitor C1 is connected to the power supply voltage input terminal Vin1, the input terminal Vin2 and the enable terminal EN, and the other end is connected to the ground terminal GND and grounded; the input terminal Vin2 of the conversion chip is short-circuited with the enable terminal EN and connected to the power supply voltage input terminal. Vin1 and one end of the first capacitor C1, the ground terminal GND is connected to the other end of the first capacitor C1 and grounded, the output terminal Vout2 is connected to one end of the inductor L, the feedback terminal FB is connected to the other end of the first resistor R1 and one end of the second resistor R2 One end of the inductor L is connected to the output terminal Vout2, and the other end is connected to one end of the first resistor R1, one end of the second capacitor C2 and the power supply voltage output terminal Vout1; one end of the second capacitor C2 is connected to the other end of the inductor L, the first resistor R1 One end of the first resistor R1 is connected to the other end of the inductor L, one end of the second capacitor C2 and the power supply voltage output end Vout1, and the other end is connected to the feedback end FB and one end of the second resistor R2; One end of the two resistors R2 is connected to the other end of the first resistor R1 and the feedback end FB, and the other end is connected to the digital-to-analog converter 1022; the controller 1021 is connected to the digital-to-analog converter 1022; the digital-to-analog converter 1022 is connected to the other end of the second resistor R2 .

In the voltage conversion circuit provided by the embodiment of the present invention, according to the principle of voltage superposition, the pre-output voltage Vfb input to the conversion chip can be decomposed into the adjustment voltage Vdac and the output voltage Vout1. When applied to the circuit respectively, the pre-output voltage Vfb can be the one between Vfb1 and Vfb2. and. As shown in FIG. 2 , the pre-output voltage Vfb can be: Vfb=Vfb1+Vfb2=Vout1R2/(R1+R2)+VdacR1/(R1+R2), thus, Vout1=(Vfb(R1+R2)- VdacR1)/R2, it can be seen from the above that besides the resistance values of the first resistor R1 and the second resistor R2, the factors affecting the output voltage Vout1 also include the regulated voltage Vdac output by the digital-to-analog converter 1022. The controller 1021 changes the regulated voltage Vdac output by the digital-to-analog converter 1022 to realize the adjustment of the output voltage Vout1 in the voltage conversion circuit. There is no need to add other additional components in the entire circuit, so it can simplify the voltage regulation in the existing voltage conversion circuit. Therefore, the reliability of the circuit can be improved, and the cost of circuit design and fabrication can be saved.

For the adjustment range of the output voltage Vout1, when Vdac is 0, the entire voltage conversion circuit can reach the maximum output voltage, namely Vfb(R1+R2)/R2; when Vdac is Vfb(R1+R2)/R1, the entire voltage conversion circuit The circuit can reach a minimum output voltage of 0V. In practical applications, if the influence of the output resistance Rout of the digital-to-analog converter 1022 on the entire circuit is considered, then Vout1=(Vfb(R1+R2+Rout)−VdacR1)/(R2+Rout), then the maximum output voltage is Vfb (R1+R2+Rout)/(R2+Rout), the minimum output voltage is 0V. Therefore, the voltage conversion circuit provided by the embodiment of the present invention can realize a larger voltage adjustment range.

For the adjustment accuracy of the output voltage Vout1, regardless of the influence of temperature, resistance accuracy and other factors on the circuit, assuming that the step voltage of Vdac is Vstep, then the step voltage of Vout1 is Vstep·R1/R2. For mature digital-to-analog converters It's very easy to get to 16 bits. Assuming that the accuracy of the digital-to-analog converter in the effective output range is 14bit, the maximum output voltage Vout1 of the voltage conversion circuit is 24V, and the pre-output voltage Vfb is 1.25V, then R1/R2=18.2, in this case, the Vout step voltage is 18.2·Vstep, that is, the output accuracy of about 10bit is achieved. If this accuracy cannot meet the actual demand, it is only necessary to improve the accuracy of the digital-to-analog converter to increase the accuracy of the output voltage Vout1 accordingly. Therefore, the voltage conversion circuit provided by the embodiment of the present invention can realize precise adjustment of the output voltage Vout1.

Embodiment 3

Based on the same inventive concept, an embodiment of the present invention provides a display device, and the display device includes the voltage conversion circuit provided by the above-mentioned embodiments. The display device may be a terminal device such as a mobile phone, a tablet computer or a smart TV. The implementation principle thereof is similar to that of the above-mentioned voltage conversion circuit, and will not be repeated here.

It can be understood that the above embodiments are only exemplary embodiments adopted to illustrate the principle of the present invention, but the present invention is not limited thereto. For those skilled in the art, without departing from the spirit and essence of the present invention, various modifications and improvements can be made, and these modifications and improvements are also regarded as the protection scope of the present invention.

Claims (11)

1. A voltage conversion circuit, characterized in that, comprising: The conversion unit is used to convert the input voltage into the output voltage and output it; an adjustment unit, used for generating an adjustment voltage according to the control instruction; a feedback unit, configured to generate a pre-output voltage according to the output voltage and the adjustment voltage, and feed it back to the conversion unit, so that the conversion unit adjusts the pre-output voltage according to the reference voltage, and obtains the adjusted output voltage for output. 2. The voltage conversion circuit according to claim 1, wherein the adjustment unit comprises: a controller and a digital-to-analog converter; The controller is connected to the digital-to-analog converter, for generating a digital signal according to the control instruction, and inputting the digital signal to the digital-to-analog converter; The digital-to-analog converter is connected to the feedback unit for converting the digital signal into an regulated voltage, and inputting the regulated voltage into the feedback unit. 3. The voltage conversion circuit according to claim 2, wherein the feedback unit comprises: a first resistor and a second resistor; One end of the first resistor is connected to the conversion unit and the power supply voltage output end, and the other end is connected to the conversion unit and one end of the second resistor; One end of the second resistor is connected to the other end of the first resistor and the conversion unit, and the other end is connected to the digital-to-analog converter. 4. The voltage conversion circuit according to claim 3, wherein the voltage conversion circuit further comprises: a first filtering unit; The first filtering unit is used for filtering the input voltage. 5. The voltage conversion circuit according to claim 4, wherein the first filtering unit comprises: a first capacitor; One end of the first capacitor is connected to the power supply voltage input end and the conversion unit, and the other end is connected to the conversion unit and grounded. 6 . The voltage conversion circuit according to claim 5 , wherein the voltage conversion circuit further comprises: a second filtering unit; 6 . The second filtering unit is used for filtering the output voltage. 7. The voltage conversion circuit according to claim 6, wherein the second filter unit comprises: an inductor and a second capacitor; One end of the inductor is connected to the conversion unit, and the other end is connected to one end of the first resistor, one end of the second capacitor and the power supply voltage output end; One end of the second capacitor is connected to the other end of the inductor, one end of the first resistor and the power supply voltage output end. 8 . The voltage conversion circuit according to claim 7 , wherein the conversion unit comprises a conversion chip; the conversion chip has: an input end, an enabling end, a ground end, an output end and a feedback end; the input end It is short-circuited with the enable terminal and connected to the power supply voltage input terminal, the ground terminal is grounded, the output terminal is connected to one end of the inductor, and the feedback terminal is connected to the other end of the first resistor and the one end of the second resistor. 9. The voltage conversion circuit according to claim 8, wherein the conversion chip comprises: a startup module, a conversion module, a comparison module and a reference voltage module; The control signal input terminal of the startup module is used as the enabling terminal; The voltage input terminal and the voltage output terminal of the conversion module are used as the input terminal and the output terminal, respectively; The positive input terminal of the comparison module is used as the feedback terminal, the negative input terminal is connected to the reference voltage module, and the signal output terminal is connected to the conversion module. 10. A voltage conversion circuit, comprising: a first capacitor, a second capacitor, a conversion chip, an inductor, a first resistor, a second resistor, a controller and a digital-to-analog converter; the conversion chip has an input terminal , enable terminal, ground terminal, output terminal and feedback terminal; One end of the first capacitor is connected to the power supply voltage input end, the input end and the enabling end, and the other end is connected to the ground end and grounded; The input terminal of the conversion chip is short-circuited with the enabling terminal and connected to the power supply voltage input terminal and one end of the first capacitor, and the ground terminal is connected to the other end of the first capacitor and grounded, the output end is connected to one end of the inductor, the feedback end is connected to the other end of the first resistor and one end of the second resistor; One end of the inductor is connected to the output end, and the other end is connected to one end of the first resistor, one end of the second capacitor and the power supply voltage output end; One end of the second capacitor is connected to the other end of the inductor, one end of the first resistor and the power supply voltage output end; One end of the first resistor is connected to the other end of the inductor, one end of the second capacitor and the power supply voltage output end, and the other end is connected to the feedback end and one end of the second resistor; One end of the second resistor is connected to the other end of the first resistor and the feedback end, and the other end is connected to the digital-to-analog converter; the controller is connected to the digital-to-analog converter; The digital-to-analog converter is connected to the other end of the second resistor. 11. A display device, comprising the voltage conversion circuit according to claim 10.

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