12-12-2012, 01:13 PM
CCFL Backlight
CCFL.ppt (Size: 899 KB / Downloads: 28)
L6574 Dedicated IC for Lighting
Feature:
High voltage rail up to 600v
Driver current capability – source 250 mA sink 450 mA
Under voltage lockout
Preheat and frequency shift timing
Integrated bootstrap diode
Integrated Sense op amp for close loop or protection
Function DisplaySteady State
L6574 deploys a ZVS operation of both MOSFETs, minimizing the power loss in switching. Lamp current loop control gives accurate current regulation towards variable input voltage
Conclusion
Complying with all the performance demands, L6574 provides a valuable solution to CCFL backlight.
Standby
Soft start
Analog & Digital dimming
Open lamp, over voltage, short circuit protection
Above 85% efficiency
The load should always be the display panel not single tube, all the parameters including frequency should be tuned with specific panel.