LED背光驱动电路及其LED驱动电流控制方法
By controlling the gate voltage of the MOS switch and using a DAC-type access resistor unit, the state transition delay of the MOS switch is adjusted, solving the problem of inconsistent LED driving current accuracy and achieving a more uniform backlight display effect.
CN119600955BActive Publication Date: 2026-07-17X SIGNAL INTEGRATED CO LTD
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- X SIGNAL INTEGRATED CO LTD
- Filing Date
- 2024-12-26
- Publication Date
- 2026-07-17
AI Technical Summary
Technical Problem
In the prior art, the inconsistent delay in the cutoff and on state transition of the MOS switch leads to inconsistent LED drive current accuracy, especially in low-brightness displays where the brightness difference between backlight zones is obvious.
Method used
By controlling the gate voltage of the MOS switch in PWM dimming mode, and combining the DAC-type access resistor unit and load unit, the state transition delay of the MOS switch is adjusted to make the delay time consistent in the off and on states, thereby improving current accuracy.
Benefits of technology
It effectively shortens the state transition delay time of the MOS switch, improves the accuracy of the LED drive current, and reduces the uneven brightness of the backlight display device.
✦ Generated by Eureka AI based on patent content.
Smart Images
Figure CN119600955B_ABST
Abstract
本发明公开了一种LED背光驱动电路，所述LED背光驱动电路包括：LED灯串；串联于所述LED灯串上的MOS开关管；运算放大器；由PWM信号控制的DAC型接入电阻单元；并联于所述DAC型接入电阻单元的负载单元；其中，所述MOS开关管的源极或漏极中的一端连接所述LED灯串，其另一端接入所述DAC型接入电阻单元；当所述MOS开关管处于截止状态时，所述MOS开关管的栅极电压被钳位至预设值。
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