AS3820 datasheet(24/52 Pages) DIALOG

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AS3820

16-Channel White LED Controller for LCD Backlight

Rev. 1.1

Datasheet

www.dialog-semiconductor.com

24 of 52

05-Feb-2019

If UPDATEmode = 0 new data from the serial interface are store immediately after xCS goes high and will take effect

after current PWM cycle is finished. In this mode the values in the PWMxdel registers are ignored. There will be no

Delay on the PWM signals.

Figure 8.8 : UPDATE mode

The PWMxHT-values are double buffered. HighTime values for the next VSYNC can be written even when the current

HighTime is not finished.

Within the first two HSYNC pulses after rising VSYNC no SPI data transfer is allowed.

8.2.5 Direct PWM Mode

The internal signals PWMx can also be direct applied at the VSYNC input if the bit Direct_PWM =1.

In this mode the default driver has the following configuration:

• All current outputs are ON

• All feedback controls are enabled and connected to FB1

• Open LED detection is enabled

• Open LED detection auto turn OFF function is enabled

• Open LED detection retrial function is enabled

• Short LED detection (Short-COMP) is enabled

• Short LED detection auto turn OFF function is enabled

• Undervoltage lockout and overtemperature detection are enabled

In this mode the device starts with default settings and can still be programmed via SPI.

AS3820 bảng dữ liệu(PDF) 24 Page - Dialog Semiconductor