xE922-3GR Hardware User Guide
1VV0301272
Rev.0.8 2017-01-05
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A typical application of the backlight control is drawn in below figure .
LEDDRV controls the gate of an external NFET with PWM signal.
During first time period t1 the inductor L is charged via the n-channel FET closed , while during second period
t2 the inductor L is discharged via the parallel LED’s.
CABC = Content Adaptive Backlight Control input from external backlighting control IC.
In order to keep the ‘perceived’ brightness the
same, the brightness of the LED backlight can be dimmed while
increasing the light shining through the LCD filter. When CABC operation is enabled, the LEDDRV PWM is
kept low/disabled when the CABC signal is low.
This way the backlight power consumption can be reduced.
Please consult the appropriate application note on Intel’s IBL support website.
10.4.
LED_CURSINK
PAD
Signal
I/O
descriptions
Type
AR14
LED_CURSINK
I
GP LED Driver (Sink)
Analog
The LED_CURSINK features a programmable (in steps of 2mA) current sink up to 40mA, typically used for
LED keypad backlighting.