Abnormal sound prevention backlight driving method based on low duty ratio input
A technology of backlight drive and low duty cycle, which is applied to instruments, static indicators, etc., can solve problems such as the inability to prevent, adjust the brightness of the backlight, abnormal noise, etc. The effect of light and noise prevention
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Embodiment 1
[0027] In the design of the display screen, in order to avoid the PWM frequency resonating with the internal structure of the display screen and causing abnormal noise, the PWM frequency will be set at about 20KHz. When the PWM frequency increases, the conduction of the IC internal switch will The transit time is smaller. For this reason, on the basis of the low duty cycle input requirement, it is impossible to simultaneously prevent abnormal noise and adjust the brightness of the backlight.
[0028] Such as Figure 3-4 As shown, in order to solve the above problems, this embodiment proposes a low duty cycle input-based anti-abnormal backlight driving method, including the following steps:
[0029] S100. Obtain the minimum duty cycle Dmin of the PWM signal when the backlight driving IC is working.
[0030] Before outputting the PWM signal to the backlight driver IC, the minimum duty cycle required by the backlight driver IC must be obtained to ensure the normal startup of th...
Embodiment 2
[0043] This embodiment proposes an anti-abnormal backlight driving method based on a low duty cycle input, which also includes the following steps:
[0044] S100. Obtain the minimum duty ratio Dmin of the PWM signal when the backlight driving IC is working.
[0045] S200. Set the working duty ratio Dx of the PWM signal output to the backlight driving IC.
[0046] S300. Comparing the required duty ratio D required to be input by the automobile manufacturer and the working duty ratio Dx.
[0047] S400. If the required duty cycle D is not greater than the set working duty cycle Dx, adjust the PWM frequency output to the backlight driver IC to fL;
[0048] If the duty cycle D is required to be greater than the set duty cycle Dx, the PWM frequency output to the backlight driver IC is adjusted to fH.
[0049] As a further improvement of the technical solution, the difference between this embodiment and Embodiment 1 is that in order to ensure that the backlight driver IC responds t...
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