WO2017206217A1 - 直流电压转换电路及液晶显示装置 - Google Patents

直流电压转换电路及液晶显示装置 Download PDF

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Publication number
WO2017206217A1
WO2017206217A1 PCT/CN2016/086782 CN2016086782W WO2017206217A1 WO 2017206217 A1 WO2017206217 A1 WO 2017206217A1 CN 2016086782 W CN2016086782 W CN 2016086782W WO 2017206217 A1 WO2017206217 A1 WO 2017206217A1
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Prior art keywords
thin film
film transistor
voltage
conversion circuit
circuit
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PCT/CN2016/086782
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English (en)
French (fr)
Inventor
曹丹
Original Assignee
深圳市华星光电技术有限公司
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Priority to US15/118,873 priority Critical patent/US10181790B2/en
Publication of WO2017206217A1 publication Critical patent/WO2017206217A1/zh

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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
    • H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
    • H02M3/10—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M3/145—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M3/155—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/156—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators
    • H02M3/157—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators with digital control
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/13306—Circuit arrangements or driving methods for the control of single liquid crystal cells
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
    • G09G3/3611—Control of matrices with row and column drivers
    • G09G3/3696—Generation of voltages supplied to electrode drivers
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
    • H02H3/02—Details
    • H02H3/021—Details concerning the disconnection itself, e.g. at a particular instant, particularly at zero value of current, disconnection in a predetermined order
    • H02H3/023—Details concerning the disconnection itself, e.g. at a particular instant, particularly at zero value of current, disconnection in a predetermined order by short-circuiting
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
    • H02H3/20—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess voltage
    • H02H3/202—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess voltage for dc systems
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
    • H02H3/24—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to undervoltage or no-voltage
    • H02H3/243—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to undervoltage or no-voltage for DC systems
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
    • H02H7/10—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers
    • H02H7/12—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers
    • H02H7/1213—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers for DC-DC converters
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
    • H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
    • H02M3/10—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M3/145—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M3/155—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/156—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2310/00—Command of the display device
    • G09G2310/02—Addressing, scanning or driving the display screen or processing steps related thereto
    • G09G2310/0243—Details of the generation of driving signals
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2310/00—Command of the display device
    • G09G2310/02—Addressing, scanning or driving the display screen or processing steps related thereto
    • G09G2310/0264—Details of driving circuits
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2330/00—Aspects of power supply; Aspects of display protection and defect management
    • G09G2330/02—Details of power systems and of start or stop of display operation
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2330/00—Aspects of power supply; Aspects of display protection and defect management
    • G09G2330/02—Details of power systems and of start or stop of display operation
    • G09G2330/026—Arrangements or methods related to booting a display
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/0003—Details of control, feedback or regulation circuits
    • H02M1/0012—Control circuits using digital or numerical techniques

Definitions

  • the present invention relates to the field of display, and in particular, to a DC voltage conversion circuit and a liquid crystal display device.
  • a liquid crystal display device generally includes a circuit board, a backlight module, and a liquid crystal display panel.
  • the circuit board is used to drive the backlight module and the liquid crystal display panel.
  • the backlight module is used to provide light to the liquid crystal display panel, and the liquid crystal display panel is used to display information such as text and images.
  • the circuit board typically includes a DC voltage conversion circuit for converting the received first DC voltage to a second DC voltage and outputting the second DC voltage. Wherein the first DC voltage is not equal to the second DC voltage.
  • the DC voltage conversion circuit When the first DC voltage is greater than the second DC voltage, the DC voltage conversion circuit is a step-down circuit, and when the first DC voltage is less than the second DC voltage, the DC voltage conversion circuit is Pressure circuit.
  • the voltage conversion circuit in the prior art does not include an abnormality (for example, a voltage conversion circuit to ground short) detection circuit. When an abnormality occurs in the voltage conversion circuit, the current passing through the electronic components in the voltage conversion circuit exceeds a preset current (for example, a rated operating current), thereby causing the electronic components in the voltage conversion circuit to burn out.
  • a preset current for example, a rated operating current
  • the present invention provides a DC voltage conversion circuit
  • the DC conversion circuit includes a control chip, a conversion circuit and a protection circuit
  • the control chip is electrically connected to the conversion circuit
  • the control chip generates a control signal and a raw voltage signal.
  • the conversion circuit receives the control signal and the original voltage signal, and obtains a DC voltage signal according to the original voltage signal under the control of the control signal
  • the protection circuit detects the conversion according to the DC voltage signal Whether the circuit is abnormal and is in the The conversion circuit is turned off when an abnormality occurs in the conversion circuit.
  • the protection circuit includes a detection circuit, a determination circuit and a control circuit, the detection circuit detects a feedback voltage of the conversion circuit, the determination circuit receives the feedback voltage, and the feedback voltage and a preset Comparing voltages, and determining whether an abnormality occurs in the conversion circuit according to a comparison result of the feedback voltage and the preset voltage, and when the determining circuit determines that an abnormality occurs in the conversion circuit, the control circuit controls the The control chip turns off the conversion circuit.
  • the detection circuit includes a detection input end and a detection output end.
  • the detection input end is electrically connected to the conversion circuit for receiving the feedback voltage, and the feedback voltage is sent through the detection output end. Output.
  • the determining circuit includes a first thin film transistor, a second thin film transistor, a third thin film transistor, a fourth thin film transistor, a first resistor, a second resistor, a third resistor, and a first operational amplifier, the first operational amplifier a first input terminal, a second input terminal, and a first output terminal, wherein a gate of the first thin film transistor receives a first gate control signal, and a drain of the first transistor is used as an input terminal of the determining circuit Connecting the detection output end, the source of the first transistor electrically connects the first resistor and the second resistor to ground, and the gate of the second thin film transistor is electrically connected to the third film a drain of the transistor, a drain of the second thin film transistor is electrically connected to the first input terminal, and a source of the second thin film transistor is connected to a node between the first resistor and the second resistor a gate of the third thin film transistor is electrically connected to the first output end, a source of the third thin film transistor is grounded, and a gate
  • the voltage at the node between the first resistor and the second resistor is named as a first detection voltage, and when the first detection voltage is less than the first reference voltage, the conversion circuit is abnormal.
  • the first output terminal outputs a first output signal that is a low level, and the third thin film transistor and the fourth thin film transistor are turned off.
  • the conversion circuit when the first detection voltage is greater than the first reference voltage, the conversion circuit is normal, the first output terminal outputs a first output signal that is a high level, and the first thin film transistor is in the Narrative A gate control signal is turned on, the second thin film transistor is turned off, and the third thin film transistor and the fourth thin film transistor are turned on.
  • the control circuit includes a second operational amplifier and a waveform controller, and the second operational amplifier includes a third input terminal, a fourth input terminal, and a second output terminal, and the third input terminal serves as the control circuit An input end, the third input end is electrically connected to an output end of the determining circuit, the fourth input end receives a second reference voltage, and the second operational amplifier is based on a voltage signal and a load applied by the third input end
  • the second reference voltage generates a second output signal
  • the second output signal is output via the second output terminal, and when the conversion circuit is abnormal, the second output signal controls the waveform controller to turn off The output channel of the original voltage signal.
  • the second output signal controls the waveform controller to output a first square wave signal and a second square wave signal
  • the control chip is configured according to the first square wave signal and the The second square wave signal obtains the original voltage signal
  • the protection circuit further includes a timer, a current source, a fifth thin film transistor, a sixth thin film transistor, and a fourth resistor, wherein the timer includes a timing input end and a timing output end, and the timing output end is electrically connected to the a gate of the fifth thin film transistor, wherein the timing output terminal is electrically connected to the gate of the first thin film transistor, and a drain of the fifth thin film transistor is electrically connected to the gate of the sixth thin film transistor, the a source of the fifth thin film transistor is grounded, a drain of the sixth thin film transistor is electrically connected to the current source, and the first voltage is loaded by the current source, and a source of the sixth thin film transistor is electrically connected to the An input end of the determining circuit, the fourth resistor is electrically connected to the drain of the fifth thin film transistor, and the other end is loaded with the first voltage, and the conversion circuit includes a first capacitor, a fifth resistor, and a sixth resistor.
  • the first capacitor is grounded at one end, and the other end is electrically connected to the detecting input end.
  • the fifth resistor is grounded at one end, the other end is electrically connected to the detecting input end, and the sixth resistor is electrically connected at one end.
  • the detection input terminal is electrically connected to the output end of the conversion circuit, and when the timing input terminal receives the high level signal, the timer is triggered to start timing, and the timing output terminal outputs a low level.
  • the timer output is a timing output signal of a high level, the first thin film transistor and the fifth thin film transistor are turned on, the sixth thin film transistor is turned off, the first capacitor is charged, and the triggering is performed.
  • the detection circuit starts working.
  • the abnormality of the conversion circuit includes short-circuiting the output end of the conversion circuit to the ground.
  • the present invention also provides a liquid crystal display device comprising the DC voltage conversion circuit according to any of the above embodiments.
  • the DC voltage conversion circuit of the present invention includes a control chip, a conversion circuit and a protection circuit.
  • the control chip is electrically connected to the conversion circuit, the control chip generates a control signal and an original voltage signal, and the conversion circuit receives the control signal and the original voltage signal, and is controlled by the control signal according to the control signal
  • the original voltage signal is a DC voltage signal that is output via an output of the conversion circuit.
  • the protection circuit is configured to detect whether an abnormality occurs in the conversion circuit, and turn off the conversion circuit when an abnormality occurs in the conversion circuit.
  • the abnormality of the conversion circuit includes, but is not limited to, short-circuiting the output terminal of the conversion circuit to the ground. It can be seen that the DC voltage conversion circuit of the present invention can turn off the DC conversion circuit when an abnormality occurs in the conversion circuit, thereby protecting the electronic components in the DC conversion circuit from being burnt.
  • FIG. 1 is a circuit block diagram of a DC voltage conversion circuit according to a preferred embodiment of the present invention.
  • FIG. 2 is a circuit block diagram of a protection circuit in a DC voltage conversion circuit according to a preferred embodiment of the present invention.
  • FIG. 3 is a schematic diagram showing the circuit structure of a DC voltage conversion circuit according to a preferred embodiment of the present invention.
  • FIG. 4 is a schematic structural view of a liquid crystal display device according to a preferred embodiment of the present invention.
  • FIG. 1 is a circuit block diagram of a DC voltage conversion circuit according to a preferred embodiment of the present invention
  • FIG. 2 is a protection of a DC voltage conversion circuit according to a preferred embodiment of the present invention
  • Circuit block diagram of the circuit
  • FIG. 3 is a schematic circuit diagram of a DC voltage conversion circuit according to a preferred embodiment of the present invention.
  • the DC voltage conversion circuit 1 includes a control chip 10, a conversion circuit 30, and a protection circuit 50.
  • the control chip 10 is electrically connected to the conversion circuit 30, the control chip 10 generates a control signal and an original voltage signal, and the conversion circuit 30 receives the control signal and the original voltage signal, and the control signal A DC voltage signal is obtained according to the original voltage signal under control, and the DC voltage signal is output via an output of the conversion circuit 30.
  • the protection circuit 50 detects whether an abnormality occurs in the conversion circuit 30 according to the DC voltage signal, and turns off the conversion circuit 30 when an abnormality occurs in the conversion circuit 30.
  • the abnormality of the conversion circuit 30 includes, but is not limited to, short-circuiting the output terminal of the conversion circuit 30 to the ground.
  • the protection circuit 50 includes a detection circuit 510, a determination circuit 530, and a control circuit 550.
  • the detection circuit 510 is electrically connected to the conversion circuit 30 and detects a feedback voltage of the conversion circuit 30, wherein the feedback voltage can be derived according to the DC voltage signal.
  • the determining circuit 530 is electrically connected to the detecting circuit 510, the determining circuit 530 receives the feedback voltage, compares the feedback voltage with a preset voltage, and according to the feedback voltage and the preset voltage The comparison result determines whether or not an abnormality has occurred in the conversion circuit 30.
  • the control circuit 550 is electrically connected to the determination circuit 530.
  • the control circuit 550 controls the control chip 10 to turn off the conversion circuit 30.
  • the input end of the detecting circuit 510 serves as an input end of the protection circuit 50.
  • An output of the control circuit 550 serves as an output of the protection circuit 50.
  • the detecting circuit 510 includes a detecting input terminal FVAA and a detecting output terminal OUTA.
  • the detection input terminal FVAA is electrically connected to the conversion circuit 30 for receiving the feedback voltage, and the feedback voltage is output through the detection output terminal OUTA.
  • the determining circuit 530 includes a first thin film transistor Q75, a second thin film transistor Q74, a third thin film transistor Q73, a fourth thin film transistor Q78, a first resistor R1, a second resistor R2, a third resistor R214, and a first operational amplifier OP1.
  • the first operational amplifier OP1 includes a first input terminal FB1, a second input terminal Vref1, and a first output terminal output1.
  • a gate of the first thin film transistor Q75 receives a first gate control signal, the first crystal
  • the drain of the transistor Q75 is electrically connected to the detection output terminal OUTA
  • the source of the first thin film transistor Q75 is electrically connected to the first resistor R1 and the second resistor R2.
  • a gate of the second thin film transistor Q74 is electrically connected to a drain of the third thin film transistor Q73
  • a drain of the second thin film transistor Q74 is electrically connected to the first input terminal FB1
  • the second film The source of the transistor Q74 is electrically connected to the node FB between the first resistor R1 and the second resistor R2.
  • the gate of the third thin film transistor Q73 is electrically connected to the first output terminal output1, and the source of the third thin film transistor Q73 is grounded.
  • a gate of the fourth thin film transistor Q78 is electrically connected to a gate of the third thin film transistor Q73, a drain of the fourth thin film transistor Q78 serves as an output end of the determining circuit 530, and the fourth thin film transistor Q78
  • the source is electrically connected to a node between the first resistor R1 and the second resistor R2.
  • One end of the third resistor R214 receives a first voltage VCC, and the other end of the third resistor R214 is electrically connected to a gate of the second thin film transistor Q74.
  • the second input terminal Vref1 of the first operational amplifier OP1 receives the first reference voltage.
  • the voltage at the node FB between the first resistor R1 and the second resistor R2 is named as a first detection voltage, and when the first detection voltage is less than the first reference voltage, the conversion circuit An abnormality occurs, the first output terminal output1 outputs a first output signal of a low level, and the third thin film transistor Q73 and the fourth thin film transistor Q78 are turned off.
  • the conversion circuit 30 When the first detection voltage is greater than the first reference voltage, the conversion circuit 30 is normal, the first output terminal output1 outputs a first output signal of a high level, and the first thin film transistor Q75 is The control of the first gate control signal is turned on, the second thin film transistor Q74 is turned off, and the third thin film transistor Q73 and the fourth thin film transistor Q78 are turned on.
  • the control circuit 550 includes a second operational amplifier OP2 and a waveform controller 553.
  • the second operational amplifier OP2 includes a third input terminal FB2, a fourth input terminal Vref2, and a second output terminal output2.
  • the third input terminal FB2 serves as an input terminal of the control circuit, and the third input terminal FB2 is electrically connected to an output terminal of the determination circuit 530.
  • the fourth input terminal Vref2 receives a second reference voltage, and the second operational amplifier OP2 generates a second output signal according to the voltage signal loaded by the third input terminal FB2 and the second reference voltage, the second output The signal is output via the second output terminal output2.
  • the second output signal controls the waveform controller 553 to turn off the output channel of the original voltage signal when an abnormality occurs in the conversion circuit 30.
  • the second output signal controls the waveform controller 553 when the conversion circuit 30 is normal And outputting the first square wave signal and the second square wave signal.
  • the control chip 10 obtains the original voltage signal according to the first square wave signal and the second square wave signal. Specifically, the port labeled LXA1 in the control chip 10 is electrically connected to the port labeled LXA1 of the waveform controller 553, and the port labeled LXA2 in the control chip 10 is marked with the waveform controller 553. Electrically connected to the port of the LXA2.
  • the first square wave signal is output to the LXA1 port of the waveform controller 553 via the LXA1 port of the waveform controller 553, and the second square wave signal is output to the RXA2 port via the waveform controller 553 The LXA2 port of the waveform controller 553.
  • the protection circuit 50 further includes a timer 560, a current source 570, a fifth thin film transistor Q76, a sixth thin film transistor Q77, and a fourth resistor R215.
  • the timer 560 includes a timing input terminal PWRON and a timing output terminal Control.
  • the timing output terminal PWRON is electrically connected to the gate of the fifth thin film transistor Q76, and the timing output terminal PWRON is electrically connected to the gate of the first thin film transistor Q75.
  • the drain of the fifth thin film transistor Q76 is electrically connected to the gate of the sixth thin film transistor Q77, and the source of the fifth thin film transistor Q76 is grounded.
  • the drain of the sixth thin film transistor Q77 is electrically connected to the current source 570, and the first voltage is loaded by the current source 570, and the source of the sixth thin film transistor Q77 is electrically connected to the determining circuit 530. Input.
  • One end of the fourth resistor R215 is electrically connected to the drain of the fifth thin film transistor Q76, and the other end is loaded with the first voltage VCC.
  • the conversion circuit 30 includes a first capacitor C93, a fifth resistor R228, and a sixth resistor R234.
  • the first capacitor C93 is grounded at one end, and the other end is electrically connected to the detection input terminal FVAA.
  • the fifth resistor R228 is grounded at one end, and the other end is electrically connected to the detecting input terminal FVAA.
  • One end of the sixth resistor R234 is electrically connected to the detection input terminal FVAA, and the other end is electrically connected to the output end VAA of the conversion circuit 30.
  • the timer 560 When the timing input terminal PWRON receives a high level signal, the timer 560 is triggered to start timing, and the timing output terminal Control outputs a timing output signal of a low level signal. At this time, the first thin film transistor Q75 and the fifth thin film transistor Q76 are turned off, the sixth thin film transistor Q77 is turned on, and the current source 570 charges the first capacitor C93.
  • the timer 560 When the timer 560 is timed out, the timer 560 outputs a timing output signal of a high level, the first thin film transistor Q75 and the fifth thin film transistor Q76 are turned on, and the sixth thin film transistor Q77 is turned on.
  • the detection circuit 510 After the first capacitor C93 is charged, the detection circuit 510 is triggered. start working. That is, the detection circuit 510 is triggered to detect the feedback voltage of the conversion circuit 30.
  • the abnormality of the conversion circuit 30 includes the output terminal VAA of the conversion circuit 30 being short-circuited to the ground.
  • the high level signal is a signal whose voltage is greater than the first preset threshold voltage.
  • the first preset threshold voltage may be 3.3V or 5V.
  • the low level signal is a signal whose voltage is less than a second preset threshold voltage, for example, the second preset threshold voltage may be 3.3V.
  • the DC voltage conversion circuit 1 of the present invention includes a control chip 10, a conversion circuit 30, and a protection circuit 50.
  • the control chip 10 is electrically connected to the conversion circuit 30, the control chip 10 generates a control signal and an original voltage signal, and the conversion circuit 30 receives the control signal and the original voltage signal, and the control signal A DC voltage signal is obtained according to the original voltage signal under control, and the DC voltage signal is output via an output of the conversion circuit 30.
  • the protection circuit 50 is configured to detect whether an abnormality occurs in the conversion circuit 30, and turn off the conversion circuit 30 when an abnormality occurs in the conversion circuit 30.
  • the abnormality of the conversion circuit 30 includes, but is not limited to, short-circuiting the output terminal of the conversion circuit 30 to the ground. It can be seen that the DC voltage conversion circuit 1 of the present invention can turn off the DC conversion circuit 30 when an abnormality occurs in the conversion circuit 30, thereby protecting the electronic components in the DC conversion circuit 30 from being burnt.
  • FIG. 4 is a schematic structural diagram of a liquid crystal display device according to a preferred embodiment of the present invention.
  • the liquid crystal display device a includes the liquid crystal display panel common voltage adjusting circuit described above, and details are not described herein again.
  • the liquid crystal display device a includes but is not limited to, but not limited to, a smart phone, a mobile device (MID), an e-book, a tablet computer, and a portable play station (Play Station Portable).
  • Portable devices such as PSP) or Personal Digital Assistant (PDA).

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Abstract

一种直流电压转换电路（1）及液晶显示装置（a），该直流电压转换电路（1）包括控制芯片（10）、转换电路（30）及保护电路（50），该控制芯片（10）与该转换电路（30）电连接，该控制芯片（10）产生控制信号及原始电压信号，该转换电路（30）接收该控制信号及该原始电压信号，并在该控制信号的控制下根据该原始电压信号得到直流电压信号，该保护电路（50）根据该直流电压信号侦测该转换电路（30）是否发生异常，并在该转换电路（30）发生异常时关闭该转换电路（30）。

Description

直流电压转换电路及液晶显示装置
本发明要求2016年5月31日递交的发明名称为“直流电压转换电路及液晶显示装置”的申请号201610377391.8的在先申请优先权，上述在先申请的内容以引入的方式并入本文本中。
技术领域
本发明涉及显示领域，尤其涉及一种直流电压转换电路及液晶显示装置。
背景技术
随着显示技术的发展，液晶显示装置由于具有体积小、功耗低等优点而得到广大用户的青睐。液晶显示装置通常包括电路板、背光模组及液晶显示面板。电路板用于驱动背光模组及液晶显示面板。背光模组用于为液晶显示面板提供光线，液晶显示面板用于显示文字、图像等信息。电路板中通常包括用于直流电压转换电路，以将接收到的第一直流电压转换为第二直流电压，并将所述第二直流电压输出。其中，所述第一直流电压不等于所述第二直流电压。当所述第一直流电压大于所述第二直流电压时，所述直流电压转换电路为降压电路，当所述第一直流电压小于所第二直流电压时，所述直流电压转换电路为升压电路。然而，现有技术中的电压转换电路中不包括异常(比如，电压转换电路对地短路)检测电路。当电压转换电路发生异常时，会导致经过电压转换电路中的电子元件的电流超过预设电流(比如，额定工作电流)，进而导致电压转换电路中的电子元件烧毁。
发明内容
本发明提供一种直流电压转换电路，所述直流转换电路包括控制芯片、转换电路及保护电路，所述控制芯片与所述转换电路电连接，所述控制芯片产生控制信号及原始电压信号，所述转换电路接收所述控制信号及所述原始电压信号，并在所述控制信号的控制下根据所述原始电压信号得到直流电压信号，所述保护电路根据所述直流电压信号侦测所述转换电路是否发生异常，并在所述 转换电路发生异常时关闭所述转换电路。
其中，所述保护电路包括侦测电路、判断电路及控制电路，所述侦测电路侦测所述转换电路的反馈电压，所述判断电路接收所述反馈电压，将所述反馈电压与预设电压进行比较，并根据所述反馈电压与所述预设电压的比较结果判断所述转换电路是否发生异常，当所述判断电路判断出所述转换电路发生异常时，所述控制电路控制所述控制芯片关闭所述转换电路。
其中，所述侦测电路包括侦测输入端及侦测输出端，所述侦测输入端电连接所述转换电路，用于接收所述反馈电压，所述反馈电压经由所述侦测输出端输出。
其中，所述判断电路包括第一薄膜晶体管、第二薄膜晶体管、第三薄膜晶体管、第四薄膜晶体管、第一电阻、第二电阻、第三电阻及第一运算放大器，所述第一运算放大器包括第一输入端、第二输入端及第一输出端，所述第一薄膜晶体管的栅极接收第一栅极控制信号，所述第一晶体管的漏极作为所述判断电路的输入端电连接所述侦测输出端，所述第一晶体管的源极依次电连接所述第一电阻及所述第二电阻至地，所述第二薄膜晶体管的栅极电连接至所述第三薄膜晶体管的漏极，所述第二薄膜晶体管的漏极电连接至所述第一输入端，所述第二薄膜晶体管的源极连接至所述第一电阻与所述第二电阻之间的节点，所述第三薄膜晶体管的栅极电连接所述第一输出端，所述第三薄膜晶体管的源极接地，所述第四薄膜晶体管的栅极电连接所述第三薄膜晶体管的栅极，所述第四薄膜晶体管的漏极作为所述判断电路的输出端，所述第四薄膜晶体管的源极电连接至所述第一电阻与所述第二电阻之间的节点，所述第三电阻的一端接收第一电压，所述第三电阻的另一端电连接至所述第二薄膜晶体管的栅极，所述第一运算放大器的第二输入端接收第一参考电压，
所述第一电阻与所述第二电阻之间的节点处的电压命名为第一侦测电压，当所述第一侦测电压小于所述第一参考电压时，所述转换电路发生异常，所述第一输出端输出为低电平的第一输出信号，所述第三薄膜晶体管及所述第四薄膜晶体管截止。
其中，当所述第一侦测电压大于所述第一参考电压时，所述转换电路正常，所述第一输出端输出为高电平的第一输出信号，所述第一薄膜晶体管在所述第 一栅极控制信号的控制下导通，所述第二薄膜晶体管截止，所述第三薄膜晶体管及所述第四薄膜晶体管导通。
其中，所述控制电路包括第二运算放大器及波形控制器，所述第二运算放大器包括第三输入端、第四输入端及第二输出端，所述第三输入端作为所述控制电路的输入端，所述第三输入端电连接所述判断电路的输出端，所述第四输入端接收第二参考电压，所述第二运算放大器根据所述第三输入端加载的电压信号及所述第二参考电压产生第二输出信号，所述第二输出信号经由所述第二输出端输出，当所述转换电路发生异常时，所述第二输出信号控制所述波形控制器关断所述原始电压信号的输出通道。
其中，当所述转换电路正常时，所述第二输出信号控制所述波形控制器输出第一方波信号及第二方波信号，所述控制芯片根据所述第一方波信号及所述第二方波信号得到所述原始电压信号。
其中，所述保护电路还包括定时器、电流源、第五薄膜晶体管、第六薄膜晶体管及第四电阻，所述定时器包括定时输入端及定时输出端，所述定时输出端电连接所述第五薄膜晶体管的栅极，且所述定时输出端电连接所述第一薄膜晶体管的栅极，所述第五薄膜晶体管的漏极电连所述第六薄膜晶体管的栅极，所述第五薄膜晶体管的源极接地，所述第六薄膜晶体管的漏极电连接所述电流源，并通过所述电流源加载所述第一电压，所述第六薄膜晶体管的源极电连接所述判断电路的输入端，所述第四电阻一端电连接所述第五薄膜晶体管的漏极，另一端加载所述第一电压，所述转换电路包括第一电容、第五电阻及第六电阻，所述第一电容一端接地，另一端电连接所述侦测输入端，所述第五电阻一端接地，另一端电连接所述侦测输入端，所述第六电阻一端电连接所述侦测输入端，另一端电连接所述转换电路的输出端，当所述定时输入端接收到高电平信号时，触发所述定时器开始计时，所述定时输出端输出为低电平信号的定时输出信号，所述第一薄膜晶体管及所述第五薄膜晶体管截止，所述第六薄膜晶体管导通，所述电流源对所述第一电容充电；当所述定时器定时结束时，所述定时器输出为高电平的定时输出信号，所述第一薄膜晶体管及所述第五薄膜晶体管导通，所述第六薄膜晶体管截止，所述第一电容充电结束，触发所述侦测电路开始工作。
其中，所述转换电路发生异常包括所述转换电路的输出端对地短路。
本发明还提供了一种液晶显示装置，所述液晶显示装置包括前述任意一实施方式所述的直流电压转换电路。
相较于现有技术，本发明的直流电压转换电路中包括控制芯片、转换电路及保护电路。所述控制芯片与所述转换电路电连接，所述控制芯片产生控制信号及原始电压信号，所述转换电路接收所述控制信号及所述原始电压信号，并在所述控制信号的控制下根据所述原始电压信号得到直流电压信号，所述直流电压信号经由所述转换电路的输出端输出。所述保护电路用于侦测所述转换电路是否发生异常，并在所述转换电路发生异常时关闭所述转换电路。在本实施方式中，所述转换电路发生异常包括但不仅限于所述转换电路的输出端对地短路。由此可见，本发明的直流电压转换电路可以在转换电路发生异常时，关闭所述直流转换电路，从而保护了所述直流转换电路中的电子元件不被烧毁。
附图说明
为了更清楚地说明本发明实施例或现有技术中的技术方案，下面将对实施例或现有技术描述中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本发明的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他的附图。
图1为本发明一较佳实施方式的直流电压转换电路的电路框图。
图2为本发明一较佳实施方式的直流电压转换电路中的保护电路的电路框图。
图3为本发明一较佳实施方式的直流电压转换电路的电路结构示意图。
图4为本发明一较佳实施方式的液晶显示装置的结构示意图。
具体实施方式
下面将结合本发明实施例中的附图，对本发明实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例仅仅是本发明一部分实施例，而不是全部的实施例。基于本发明中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本发明保护的范围。
请一并参阅图1、图2和图3，图1为本发明一较佳实施方式的直流电压转换电路的电路框图；图2为本发明一较佳实施方式的直流电压转换电路中的保护电路的电路框图；图3为本发明一较佳实施方式的直流电压转换电路的电路结构示意图。所述直流电压转换电路1包括控制芯片10、转换电路30及保护电路50。所述控制芯片10与所述转换电路30电连接，所述控制芯片10产生控制信号及原始电压信号，所述转换电路30接收所述控制信号及所述原始电压信号，并在所述控制信号的控制下根据所述原始电压信号得到直流电压信号，所述直流电压信号经由所述转换电路30的输出端输出。所述保护电路50根据所述直流电压信号侦测所述转换电路30是否发生异常，并在所述转换电路30发生异常时关闭所述转换电路30。在本实施方式中，所述转换电路30发生异常包括但不仅限于所述转换电路30的输出端对地短路。
所述保护电路50包括侦测电路510、判断电路530及控制电路550。所述侦测电路510与所述转换电路30电连接，并侦测所述转换电路30的反馈电压，其中，所述反馈电压可根据所述直流电压信号得出。所述判断电路530与所述侦测电路510电连接，所述判断电路530接收所述反馈电压，将所述反馈电压与预设电压进行比较，并根据所述反馈电压与所述预设电压的比较结果判断所述转换电路30是否发生异常。所述控制电路550与所述判断电路530电连接，当所述判断电路530判断出所述转换电路30发生异常时，所述控制电路550控制所述控制芯片10关闭所述转换电路30。其中，所述侦测电路510的输入端作为所述保护电路50的输入端。所述控制电路550的输出端作为所述保护电路50的输出端。
所述侦测电路510包括侦测输入端FVAA及侦测输出端OUTA。所述侦测输入端FVAA电连接所述转换电路30，用于接收所述反馈电压，所述反馈电压经由所述侦测输出端OUTA输出。
所述判断电路530包括第一薄膜晶体管Q75、第二薄膜晶体管Q74、第三薄膜晶体管Q73、第四薄膜晶体管Q78、第一电阻R1、第二电阻R2、第三电阻R214及第一运算放大器OP1。所述第一运算放大器OP1包括第一输入端FB1、第二输入端Vref1及第一输出端output1。
所述第一薄膜晶体管Q75的栅极接收第一栅极控制信号，所述第一晶体 管Q75的漏极作为所述判断电路530的输出端电连接所述侦测输出端OUTA，所述第一薄膜晶体管Q75的源极依次电连接所述第一电阻R1与所述第二电阻R2至地。所述第二薄膜晶体管Q74的栅极电连接至所述第三薄膜晶体管Q73的漏极，所述第二薄膜晶体管Q74的漏极电连接至所述第一输入端FB1，所述第二薄膜晶体管Q74的源极电连接至所述第一电阻R1及所述第二电阻R2之间的节点FB。所述第三薄膜晶体管Q73的栅极电连接所述第一输出端output1，所述第三薄膜晶体管Q73的源极接地。所述第四薄膜晶体管Q78的栅极电连接所述第三薄膜晶体管Q73的栅极，所述第四薄膜晶体管Q78的漏极作为所述判断电路530的输出端，所述第四薄膜晶体管Q78的源极电连接至所述第一电阻R1与所述第二电阻R2之间的节点。所述第三电阻R214的一端接收第一电压VCC，所述第三电阻R214的另一端电连接至所述第二薄膜晶体管Q74的栅极。所述第一运算放大器OP1的第二输入端Vref1接收第一参考电压。所述第一电阻R1与所述第二电阻R2之间的节点FB处的电压命名为第一侦测电压，当所述第一侦测电压小于所述第一参考电压时，所述转换电路30发生异常，所述第一输出端output1输出为低电平的第一输出信号，所述第三薄膜晶体管Q73和所述第四薄膜晶体管Q78截止。
当所述第一侦测电压大于所述第一参考电压时，所述转换电路30正常，所述第一输出端output1输出为高电平的第一输出信号，所述第一薄膜晶体管Q75在所述第一栅极控制信号的控制下导通，所述第二薄膜晶体管Q74截止，所述第三薄膜晶体管Q73和所述第四薄膜晶体管Q78导通。
所述控制电路550包括第二运算放大器OP2及波形控制器553。所述第二运算放大器OP2包括第三输入端FB2、第四输入端Vref2及第二输出端output2。所述第三输入端FB2作为所述控制电路的输入端，所述第三输入端FB2电连接所述判断电路530的输出端。所述第四输入端Vref2接收第二参考电压，所述第二运算放大器OP2根据所述第三输入端FB2加载的电压信号及所述第二参考电压产生第二输出信号，所述第二输出信号经由所述第二输出端output2输出。当所述转换电路30发生异常时，所述第二输出信号控制所述波形控制器553关断所述原始电压信号的输出通道。
当所述转换电路30正常时，所述第二输出信号控制所述波形控制器553 输出第一方波信号及所述第二方波信号。所述控制芯片10根据所述第一方波信号及所述第二方波信号得到所述原始电压信号。具体地，所述控制芯片10中标记为LXA1的端口和所述波形控制器553的标记为LXA1的端口电连接，所述控制芯片10中标记为LXA2的端口与所述波形控制器553中标记为LXA2的端口电连接。所述第一方波信号经由所述波形控制器553的LXA1端口输出至所述波形控制器553的LXA1端口，所述第二方波信号经由所述波形控制器553的LXA2端口输出至所述波形控制器553的LXA2端口。
所述保护电路50还包括定时器560、电流源570、第五薄膜晶体管Q76、第六薄膜晶体管Q77及第四电阻R215。所述定时器560包括定时输入端PWRON及定时输出端Control。所述定时输出端PWRON电连接所述第五薄膜晶体管Q76的栅极，且所述定时输出端PWRON电连接所述第一薄膜晶体管Q75的栅极。所述第五薄膜晶体管Q76的漏极电连接所述第六薄膜晶体管Q77的栅极，所述第五薄膜晶体管Q76的源极接地。所述第六薄膜晶体管Q77的漏极电连接所述电流源570，并通过所述电流源570加载所述第一电压，所述第六薄膜晶体管Q77的源极电连接所述判断电路530的输入端。所述第四电阻R215一端电连接所述第五薄膜晶体管Q76的漏极，另一端加载所述第一电压VCC。
相应地，所述转换电路30包括第一电容C93、第五电阻R228及第六电阻R234。所述第一电容C93一端接地，另一端电连接所述侦测输入端FVAA。所述第五电阻R228一端接地，另一端电连接所述侦测输入端FVAA。所述第六电阻R234一端电连接所述侦测输入端FVAA，另一端电连接所述转换电路30的输出端VAA。
当所述定时输入端PWRON接收到高电平信号时，触发所述定时器560开始计时，所述定时输出端Control输出为低电平信号的定时输出信号，此时，所述第一薄膜晶体管Q75及所述第五薄膜晶体管Q76截止，所述第六薄膜晶体管Q77导通，所述电流源570对所述第一电容C93充电。
当所述定时器560定时结束时，所述定时器560输出为高电平的定时输出信号，所述第一薄膜晶体管Q75及所述第五薄膜晶体管Q76导通，所述第六薄膜晶体管Q77截止，所述第一电容C93充电结束，触发所述侦测电路510 开始工作。即，触发所述侦测电路510侦测所述转换电路30的反馈电压。
在本实施方式中，所述转换电路30发生异常包括所述转换电路30的输出端VAA对地短路。
在本实施方式中，所述高电平信号为电压大于第一预设阈值电压的信号，比如，所述第一预设阈值电压可以为3.3V或者5V。所述低电平信号为电压小于第二预设阈值电压的信号，比如，所述第二预设阈值电压可以为3.3V。
相较于现有技术，本发明的直流电压转换电路1中包括控制芯片10、转换电路30及保护电路50。所述控制芯片10与所述转换电路30电连接，所述控制芯片10产生控制信号及原始电压信号，所述转换电路30接收所述控制信号及所述原始电压信号，并在所述控制信号的控制下根据所述原始电压信号得到直流电压信号，所述直流电压信号经由所述转换电路30的输出端输出。所述保护电路50用于侦测所述转换电路30是否发生异常，并在所述转换电路30发生异常时关闭所述转换电路30。在本实施方式中，所述转换电路30发生异常包括但不仅限于所述转换电路30的输出端对地短路。由此可见，本发明的直流电压转换电路1可以在转换电路30发生异常时，关闭所述直流转换电路30，从而保护了所述直流转换电路30中的电子元件不被烧毁。
本发明还提供了一种液晶显示装置a，请参阅图4，图4为本发明一较佳实施方式的液晶显示装置的结构示意图。所述液晶显示装置a包括前面所述的液晶显示面板公共电压调整电路，在此不再赘述。在本实施方式中，所述液晶显示装置a包括但不仅限于包括但不仅限于智能手机(Smart Phone)、互联网设备(Mobile Internet Device，MID)、电子书、平板电脑、便携式播放站(Play Station Portable，PSP)或者个人数字助理(Personal Digital Assistant，PDA)等便携式设备。
以上所揭露的仅为本发明一种较佳实施例而已，当然不能以此来限定本发明之权利范围，本领域普通技术人员可以理解实现上述实施例的全部或部分流程，并依本发明权利要求所作的等同变化，仍属于发明所涵盖的范围。

Claims (18)

  1. 一种直流电压转换电路，其中，所述直流转换电路包括控制芯片、转换电路及保护电路，所述控制芯片与所述转换电路电连接，所述控制芯片产生控制信号及原始电压信号，所述转换电路接收所述控制信号及所述原始电压信号，并在所述控制信号的控制下根据所述原始电压信号得到直流电压信号，所述保护电路依据所述直流电压信号侦测所述转换电路是否发生异常，并在所述转换电路发生异常时关闭所述转换电路。
  2. 如权利要求1所述的直流电压转换电路，其中，所述保护电路包括侦测电路、判断电路及控制电路，所述侦测电路侦测所述转换电路的反馈电压，所述判断电路接收所述反馈电压，将所述反馈电压与预设电压进行比较，并根据所述反馈电压与所述预设电压的比较结果判断所述转换电路是否发生异常，当所述判断电路判断出所述转换电路发生异常时，所述控制电路控制所述控制芯片关闭所述转换电路。
  3. 如权利要求2所述的直流电压转换电路，其中，所述侦测电路包括侦测输入端及侦测输出端，所述侦测输入端电连接所述转换电路，用于接收所述反馈电压，所述反馈电压经由所述侦测输出端输出。
  4. 如权利要求3所述的直流电压转换电路，其中，所述判断电路包括第一薄膜晶体管、第二薄膜晶体管、第三薄膜晶体管、第四薄膜晶体管、第一电阻、第二电阻、第三电阻及第一运算放大器，所述第一运算放大器包括第一输入端、第二输入端及第一输出端，
    所述第一薄膜晶体管的栅极接收第一栅极控制信号，所述第一晶体管的漏极作为所述判断电路的输入端电连接所述侦测输出端，所述第一晶体管的源极依次电连接所述第一电阻及所述第二电阻至地，所述第二薄膜晶体管的栅极电连接至所述第三薄膜晶体管的漏极，所述第二薄膜晶体管的漏极电连接至所述第一输入端，所述第二薄膜晶体管的源极连接至所述第一电阻与所述第二电阻 之间的节点，所述第三薄膜晶体管的栅极电连接所述第一输出端，所述第三薄膜晶体管的源极接地，所述第四薄膜晶体管的栅极电连接所述第三薄膜晶体管的栅极，所述第四薄膜晶体管的漏极作为所述判断电路的输出端，所述第四薄膜晶体管的源极电连接至所述第一电阻与所述第二电阻之间的节点，所述第三电阻的一端接收第一电压，所述第三电阻的另一端电连接至所述第二薄膜晶体管的栅极，所述第一运算放大器的第二输入端接收第一参考电压，所述第一电阻与所述第二电阻之间的节点处的电压命名为第一侦测电压，当所述第一侦测电压小于所述第一参考电压时，所述转换电路发生异常，所述第一输出端输出为低电平的第一输出信号，所述第三薄膜晶体管及所述第四薄膜晶体管截止。
  5. 如权利要求4所述的直流电压转换电路，其中，当所述第一侦测电压大于所述第一参考电压时，所述转换电路正常，所述第一输出端输出为高电平的第一输出信号，所述第一薄膜晶体管在所述第一栅极控制信号的控制下导通，所述第二薄膜晶体管截止，所述第三薄膜晶体管及所述第四薄膜晶体管导通。
  6. 如权利要求5所述的直流电压转换电路，其中，所述控制电路包括第二运算放大器及波形控制器，所述第二运算放大器包括第三输入端、第四输入端及第二输出端，所述第三输入端作为所述控制电路的输入端，所述第三输入端电连接所述判断电路的输出端，所述第四输入端接收第二参考电压，所述第二运算放大器根据所述第三输入端加载的电压信号及所述第二参考电压产生第二输出信号，所述第二输出信号经由所述第二输出端输出，当所述转换电路发生异常时，所述第二输出信号控制所述波形控制器关断所述原始电压信号的输出通道。
  7. 如权利要求6所述的直流电压转换电路，其中，当所述转换电路正常时，所述第二输出信号控制所述波形控制器输出第一方波信号及第二方波信号，所述控制芯片根据所述第一方波信号及所述第二方波信号得到所述原始电压信号。
  8. 如权利要求4所述的直流电压转换电路，其中，所述保护电路还包括定时器、电流源、第五薄膜晶体管、第六薄膜晶体管及第四电阻，所述定时器包括定时输入端及定时输出端，所述定时输出端电连接所述第五薄膜晶体管的栅极，且所述定时输出端电连接所述第一薄膜晶体管的栅极，所述第五薄膜晶体管的漏极电连所述第六薄膜晶体管的栅极，所述第五薄膜晶体管的源极接地，所述第六薄膜晶体管的漏极电连接所述电流源，并通过所述电流源加载所述第一电压，所述第六薄膜晶体管的源极电连接所述判断电路的输入端，所述第四电阻一端电连接所述第五薄膜晶体管的漏极，另一端加载所述第一电压，
    所述转换电路包括第一电容、第五电阻及第六电阻，所述第一电容一端接地，另一端电连接所述侦测输入端，所述第五电阻一端接地，另一端电连接所述侦测输入端，所述第六电阻一端电连接所述侦测输入端，另一端电连接所述转换电路的输出端，
    当所述定时输入端接收到高电平信号时，触发所述定时器开始计时，所述定时输出端输出为低电平信号的定时输出信号，所述第一薄膜晶体管及所述第五薄膜晶体管截止，所述第六薄膜晶体管导通，所述电流源对所述第一电容充电；当所述定时器定时结束时，所述定时器输出为高电平的定时输出信号，所述第一薄膜晶体管及所述第五薄膜晶体管导通，所述第六薄膜晶体管截止，所述第一电容充电结束，触发所述侦测电路开始工作。
  9. 如权利要求1所述的直流电压转换电路，其中，所述转换电路发生异常包括所述转换电路的输出端对地短路。
  10. 一种液晶显示装置，其中，所述液晶显示装置包括直流电压转换电路，所述直流转换电路包括控制芯片、转换电路及保护电路，所述控制芯片与所述转换电路电连接，所述控制芯片产生控制信号及原始电压信号，所述转换电路接收所述控制信号及所述原始电压信号，并在所述控制信号的控制下根据所述原始电压信号得到直流电压信号，所述保护电路依据所述直流电压信号侦测所述转换电路是否发生异常，并在所述转换电路发生异常时关闭所述转换电路。
  11. 如权利要求10所述的液晶显示装置，其中，所述保护电路包括侦测电路、判断电路及控制电路，所述侦测电路侦测所述转换电路的反馈电压，所述判断电路接收所述反馈电压，将所述反馈电压与预设电压进行比较，并根据所述反馈电压与所述预设电压的比较结果判断所述转换电路是否发生异常，当所述判断电路判断出所述转换电路发生异常时，所述控制电路控制所述控制芯片关闭所述转换电路。
  12. 如权利要求11所述的液晶显示装置，其中，所述侦测电路包括侦测输入端及侦测输出端，所述侦测输入端电连接所述转换电路，用于接收所述反馈电压，所述反馈电压经由所述侦测输出端输出。
  13. 如权利要求12所述的液晶显示装置，其中，所述判断电路包括第一薄膜晶体管、第二薄膜晶体管、第三薄膜晶体管、第四薄膜晶体管、第一电阻、第二电阻、第三电阻及第一运算放大器，所述第一运算放大器包括第一输入端、第二输入端及第一输出端，
    所述第一薄膜晶体管的栅极接收第一栅极控制信号，所述第一晶体管的漏极作为所述判断电路的输入端电连接所述侦测输出端，所述第一晶体管的源极依次电连接所述第一电阻及所述第二电阻至地，所述第二薄膜晶体管的栅极电连接至所述第三薄膜晶体管的漏极，所述第二薄膜晶体管的漏极电连接至所述第一输入端，所述第二薄膜晶体管的源极连接至所述第一电阻与所述第二电阻之间的节点，所述第三薄膜晶体管的栅极电连接所述第一输出端，所述第三薄膜晶体管的源极接地，所述第四薄膜晶体管的栅极电连接所述第三薄膜晶体管的栅极，所述第四薄膜晶体管的漏极作为所述判断电路的输出端，所述第四薄膜晶体管的源极电连接至所述第一电阻与所述第二电阻之间的节点，所述第三电阻的一端接收第一电压，所述第三电阻的另一端电连接至所述第二薄膜晶体管的栅极，所述第一运算放大器的第二输入端接收第一参考电压，所述第一电阻与所述第二电阻之间的节点处的电压命名为第一侦测电压，当所述第一侦测电压小于所述第一参考电压时，所述转换电路发生异常，所述第一输出端输出为低电平的第一输出信号，所述第三薄膜晶体管及所述第四薄膜晶体管截止。
  14. 如权利要求13所述的液晶显示装置，其中，当所述第一侦测电压大于所述第一参考电压时，所述转换电路正常，所述第一输出端输出为高电平的第一输出信号，所述第一薄膜晶体管在所述第一栅极控制信号的控制下导通，所述第二薄膜晶体管截止，所述第三薄膜晶体管及所述第四薄膜晶体管导通。
  15. 如权利要求14所述的液晶显示装置，其中，所述控制电路包括第二运算放大器及波形控制器，所述第二运算放大器包括第三输入端、第四输入端及第二输出端，所述第三输入端作为所述控制电路的输入端，所述第三输入端电连接所述判断电路的输出端，所述第四输入端接收第二参考电压，所述第二运算放大器根据所述第三输入端加载的电压信号及所述第二参考电压产生第二输出信号，所述第二输出信号经由所述第二输出端输出，当所述转换电路发生异常时，所述第二输出信号控制所述波形控制器关断所述原始电压信号的输出通道。
  16. 如权利要求15所述的液晶显示装置，其中，当所述转换电路正常时，所述第二输出信号控制所述波形控制器输出第一方波信号及第二方波信号，所述控制芯片根据所述第一方波信号及所述第二方波信号得到所述原始电压信号。
  17. 如权利要求13所述的液晶显示装置，其中，所述保护电路还包括定时器、电流源、第五薄膜晶体管、第六薄膜晶体管及第四电阻，所述定时器包括定时输入端及定时输出端，所述定时输出端电连接所述第五薄膜晶体管的栅极，且所述定时输出端电连接所述第一薄膜晶体管的栅极，所述第五薄膜晶体管的漏极电连所述第六薄膜晶体管的栅极，所述第五薄膜晶体管的源极接地，所述第六薄膜晶体管的漏极电连接所述电流源，并通过所述电流源加载所述第一电压，所述第六薄膜晶体管的源极电连接所述判断电路的输入端，所述第四电阻一端电连接所述第五薄膜晶体管的漏极，另一端加载所述第一电压，
    所述转换电路包括第一电容、第五电阻及第六电阻，所述第一电容一端接 地，另一端电连接所述侦测输入端，所述第五电阻一端接地，另一端电连接所述侦测输入端，所述第六电阻一端电连接所述侦测输入端，另一端电连接所述转换电路的输出端，
    当所述定时输入端接收到高电平信号时，触发所述定时器开始计时，所述定时输出端输出为低电平信号的定时输出信号，所述第一薄膜晶体管及所述第五薄膜晶体管截止，所述第六薄膜晶体管导通，所述电流源对所述第一电容充电；当所述定时器定时结束时，所述定时器输出为高电平的定时输出信号，所述第一薄膜晶体管及所述第五薄膜晶体管导通，所述第六薄膜晶体管截止，所述第一电容充电结束，触发所述侦测电路开始工作。
  18. 如权利要求10所述的液晶显示装置，其中，所述转换电路发生异常包括所述转换电路的输出端对地短路。
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Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106300946B (zh) * 2016-09-20 2019-05-28 深圳市华星光电技术有限公司 一种吸收电路、供电电路及液晶显示器
CN106875879B (zh) * 2017-04-24 2020-05-22 上海天马有机发光显示技术有限公司 一种显示面板、电子设备以及测试方法
CN111477182B (zh) * 2019-01-23 2022-03-04 纬联电子科技(中山)有限公司 显示装置及其断电控制方法
CN109980928A (zh) * 2019-04-24 2019-07-05 北京无线电测量研究所 一种高压输入t/r组件的通道电源故障隔离电路及装置
US11405038B2 (en) 2019-11-19 2022-08-02 Tcl China Star Optoelectronics Technology Co., Ltd. Level shifter circuit and display panel
CN110995243A (zh) * 2019-11-19 2020-04-10 Tcl华星光电技术有限公司 电平转换电路及显示面板
CN113014198B (zh) * 2021-03-31 2022-12-13 华为数字能源技术有限公司 光伏系统
CN114387932B (zh) * 2022-01-18 2022-12-16 北京奕斯伟计算技术股份有限公司 保护电路及保护方法、输出单元、源极驱动器及显示设备

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050231127A1 (en) * 2004-03-30 2005-10-20 Isao Yamamoto Boost controller capable of step-up ratio control
CN101086571A (zh) * 2006-06-07 2007-12-12 Lg.菲利浦Lcd株式会社 液晶显示器的背光驱动装置和驱动该背光驱动装置的方法
CN201611976U (zh) * 2010-01-16 2010-10-20 福建捷联电子有限公司 应用于液晶显示产品的ccfl和led灯管共用电源板
CN103295537A (zh) * 2013-05-08 2013-09-11 深圳市华星光电技术有限公司 一种led背光驱动电路、背光模组和液晶显示装置
CN103606884A (zh) * 2013-11-25 2014-02-26 深圳市华星光电技术有限公司 过流保护电路、led背光驱动电路以及液晶显示器

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4463369B2 (ja) * 2000-02-24 2010-05-19 富士通マイクロエレクトロニクス株式会社 Ｄｃ−ｄｃコンバータの制御回路及びｄｃ−ｄｃコンバータ
CN102042249B (zh) * 2009-10-12 2014-12-03 国家电网公司 电脑风扇控制电路
TWI511430B (zh) * 2013-03-14 2015-12-01 Fsp Technology Inc 電源供應裝置
TWI536706B (zh) * 2014-03-11 2016-06-01 登騰電子股份有限公司 智慧型電源轉接器及其供電控制方法
JP2017131033A (ja) * 2016-01-20 2017-07-27 株式会社デンソー スイッチング電源装置
JP6504114B2 (ja) * 2016-06-07 2019-04-24 Smk株式会社 Ｄｃ−ｄｃコンバータ

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050231127A1 (en) * 2004-03-30 2005-10-20 Isao Yamamoto Boost controller capable of step-up ratio control
CN101086571A (zh) * 2006-06-07 2007-12-12 Lg.菲利浦Lcd株式会社 液晶显示器的背光驱动装置和驱动该背光驱动装置的方法
CN201611976U (zh) * 2010-01-16 2010-10-20 福建捷联电子有限公司 应用于液晶显示产品的ccfl和led灯管共用电源板
CN103295537A (zh) * 2013-05-08 2013-09-11 深圳市华星光电技术有限公司 一种led背光驱动电路、背光模组和液晶显示装置
CN103606884A (zh) * 2013-11-25 2014-02-26 深圳市华星光电技术有限公司 过流保护电路、led背光驱动电路以及液晶显示器

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