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CN-118038817-B - Backlight driving circuit and display device

CN118038817BCN 118038817 BCN118038817 BCN 118038817BCN-118038817-B

Abstract

The embodiment of the application provides a backlight driving circuit and a display device, wherein the backlight driving circuit comprises a boosting unit, a dimming unit, a control unit and a control unit, wherein the output end of the boosting unit is connected with the first end of a backlight load, the dimming unit comprises a first resistor, the first end of the first resistor is grounded, the feedback biasing unit comprises a second resistor, the first end of the second resistor is connected with the output end of the boosting unit, the control unit is connected with the boosting unit, the dimming unit and the feedback biasing unit, the feedback end of the control unit is connected with the second end of the first resistor, the control unit is configured to control the backlight load and the first resistor to form a first loop and regulate the output of the boosting unit according to a first voltage signal of the feedback end in a first control mode, or to control the second resistor and the first resistor to form a second loop and regulate the output of the boosting unit according to a second voltage signal of the feedback end in a second control mode. By the mode, the constant voltage/current output by the boosting unit can be controlled, and the display effect is improved.

Inventors

  • HU FENG
  • HUANG XIANSHENG

Assignees

  • 广州视源电子科技股份有限公司
  • 广州视琨电子科技有限公司

Dates

Publication Date
20260512
Application Date
20221114

Claims (9)

  1. 1. A backlight driving circuit, characterized in that the backlight driving circuit comprises: The output end of the boosting unit is connected with the first end of the backlight load; The light adjusting unit comprises a first resistor, and the first end of the first resistor is grounded; The feedback bias unit comprises a second resistor, and a first end of the second resistor is connected with the output end of the boosting unit; the control unit is connected with the boosting unit, the dimming unit and the feedback biasing unit, the feedback end of the control unit is connected with the second end of the first resistor, and the control unit is configured to: In a first control mode, controlling the backlight load and the first resistor to form a first loop and regulating the output of the boosting unit according to a first voltage signal of the feedback end, or In a second control mode, controlling the second resistor and the first resistor to form a second loop, and regulating the output of the boosting unit according to a second voltage signal of the feedback end; The dimming unit comprises a first switch, wherein a first end of the first switch is connected with a second end of the backlight load, and a second end of the first switch is connected with a second end of the first resistor; The feedback bias unit comprises a second switch, a first end of the second switch is connected with a second end of the second resistor, and a second end of the second switch is connected with a second end of the first resistor; The control unit is configured to: In a first control mode, the first switch is controlled to be turned on and the second switch is controlled to be turned off, or And in a second control mode, controlling the first switch to be turned off and controlling the second switch to be turned on.
  2. 2. A backlight driving circuit according to claim 1, wherein, The feedback bias unit further includes: and the first end of the third resistor is connected with the second end of the second switch, and the second end of the third resistor is connected with the second end of the first resistor.
  3. 3. A backlight driving circuit according to claim 1, wherein, The feedback bias unit further includes: The first end of the first capacitor is connected with the first end of the second resistor; and the first end of the fourth resistor is connected with the second end of the first capacitor, and the second end of the fourth resistor is connected with the second end of the second resistor.
  4. 4. A backlight driving circuit according to claim 1, wherein, The control end of the second switch is connected with the power supply voltage end; the dimming unit further includes: the control end of the third switch is connected with the control unit, the first end of the third switch is connected with the power supply voltage end, and the second end of the third switch is grounded; the control end of the fourth switch is connected with the first end of the third switch, the first end of the fourth switch is connected with the power supply voltage end and the control end of the first switch, and the second end of the fourth switch is grounded; The control unit is configured to: In a first control mode, the third switch is controlled to be turned on to cut off the fourth switch and cut off the second switch so as to turn on the first switch, or And in a second control mode, controlling the third switch to be turned off so as to enable the fourth switch to be turned on and the second switch to be turned on, so that the first switch is turned off.
  5. 5. A backlight driving circuit according to claim 4, wherein, The first switch is an NMOS transistor, and the second switch, the third switch and the fourth switch are NPN triodes.
  6. 6. A backlight driving circuit according to claim 4, wherein, The dimming unit further includes: a first end of the fifth resistor is connected with the first end of the fourth switch, and a second end of the fifth resistor is connected with the control end of the first switch; a sixth resistor, wherein a first end of the sixth resistor is connected with a first end of the fourth switch, and a second end of the sixth resistor is connected with the power supply voltage end; A seventh resistor, wherein a first end of the seventh resistor is connected with a first end of the third switch, and a second end of the seventh resistor is connected with the power supply voltage end; and the first end of the eighth resistor is connected with the control end of the second switch, and the second end of the eighth resistor is connected with the power supply voltage end.
  7. 7. A backlight driving circuit according to claim 1, wherein, The dimming unit further includes: and the input end of the diode is connected with the second end of the first resistor, and the output end of the diode is grounded.
  8. 8. A backlight driving circuit according to claim 1, wherein, The backlight driving circuit further includes: and the input end of the filtering unit is connected with the second end of the first resistor, and the output end of the filtering unit is connected with the feedback end of the control unit.
  9. 9. A display device comprising a backlight driving circuit according to any one of claims 1 to 8.

Description

Backlight driving circuit and display device Technical Field The application relates to the technical field of display, in particular to a backlight driving circuit and a display device. Background With the development of display technology, the requirements for backlight control of display devices are also increasing. In the prior art, most backlight power supply parts of display devices such as televisions, intelligent terminals and intelligent flat panels adopt a mode of single PWM dimming, single analog dimming IC (integrated circuit) dimming and PWM+analog dimming. The existing PWM+analog dimming mode integrates an analog dimming part and a PWM dimming part into one IC, so that the cost is high, and the design is not flexible enough. Disclosure of Invention The embodiment of the application provides a backlight driving circuit and a display device, which can control constant voltage/current output by a boosting unit and improve the display effect. The application provides a backlight driving circuit which comprises a boosting unit, a dimming unit, a feedback bias unit and a control unit, wherein the output end of the boosting unit is connected with the first end of a backlight load, the dimming unit comprises a first resistor, the first end of the first resistor is grounded, the feedback bias unit comprises a second resistor, the first end of the second resistor is connected with the output end of the boosting unit, the control unit is connected with the boosting unit, the dimming unit and the feedback bias unit, the feedback end of the control unit is connected with the second end of the first resistor, the control unit is configured to control the backlight load and the first resistor to form a first loop in a first control mode and regulate the output of the boosting unit according to a first voltage signal of the feedback end, or to control the second resistor and the first resistor to form a second loop in a second control mode and regulate the output of the boosting unit according to a second voltage signal of the feedback end. In some embodiments, the dimming unit comprises a first switch, a first end of the first switch is connected with a second end of the backlight load, a second end of the first switch is connected with a second end of the first resistor, the feedback bias unit comprises a second switch, the first end of the second switch is connected with the second end of the second resistor, the second end of the second switch is connected with the second end of the first resistor, and the control unit is configured to control the first switch to be turned on and control the second switch to be turned off in a first control mode or control the first switch to be turned off and control the second switch to be turned on in a second control mode. In some embodiments, the feedback bias unit further comprises a third resistor, a first end of the third resistor being connected to the second end of the second switch, a second end of the third resistor being connected to the second end of the first resistor. In some embodiments, the feedback bias unit further comprises a first capacitor, a fourth resistor, and a third resistor, wherein the first end of the first capacitor is connected with the first end of the second resistor, the first end of the fourth resistor is connected with the second end of the first capacitor, and the second end of the fourth resistor is connected with the second end of the second resistor. In some embodiments, the control end of the second switch is connected with the power supply voltage end, the dimming unit further comprises a third switch, the control end of the third switch is connected with the control unit, the first end of the third switch is connected with the power supply voltage end, the second end of the third switch is grounded, the control end of the fourth switch is connected with the first end of the third switch, the first end of the fourth switch is connected with the power supply voltage end and the control end of the first switch, the second end of the fourth switch is grounded, and the control unit is configured to control the third switch to be turned on in a first control mode so that the fourth switch is turned off, the second switch is turned off so that the first switch is turned on, or to control the third switch to be turned off in a second control mode so that the fourth switch is turned on, and the second switch is turned off. In some embodiments, the first switch is an NMOS transistor and the second, third, and fourth switches are NPN transistors. In some embodiments, the dimming unit further comprises a fifth resistor, wherein the first end of the fifth resistor is connected with the first end of the fourth switch, the second end of the fifth resistor is connected with the control end of the first switch, the first end of the sixth resistor is connected with the first end of the fourth switch, the second end of the sixth resistor is conne