
- 55 -
Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
3. TECHNICAL BRIEF
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
3.15 KEY BACLKLIGHT LED Interface
The AD6725 Auxiliary Section provides three independent PWM light controllers.
The PWM output controllers regulate the average current through active lights.
Figure 3-15-1 ABB Light Controller Block Diagram
The output frequencies of the LIGHTx PWM output controllers are set by the Light12Period (0x2F ) and
Light3Period (0x31 ) control registers.
With fMCLK = 13 MHz, frequencies ranging from 50.781 kHz to 49.591 Hz may be specified.
fLIGHT1 = ( fMCLK / 256 ) / ( Light12Period[9:0] + 1 )
fLIGHT2 = ( fMCLK / 256 ) / ( Light12Period[9:0] + 1 )
fLIGHT3 = ( fMCLK / 256 ) / ( Light3Period[9:0] + 1 )
he output duty cycles of the PWM output controllers are set by the LightxDutyCycle[7:0] control registers –
Light1DutyCycle (0x2D ), Light2DutyCycle (0x2E) and Light3DutyCycle (0x30 ).
This model use only Light3 port and 2 high luminance white LED with light guard film.