Acer D240H service manual Backlight Unit, Parameter Min Typ Max Unit

Product Specification	M240HW01 V2
AU OPTRONICS CORPORATION

5.2 Backlight Unit

Parameter guideline for CCFL Inverter is under stable conditions at 25℃ (Room Temperature):

Parameter	Min.		Typ.	Max.		Unit	Note
CCFL Standard Current (ISCFL)	7.0	7.5		8.0		[mA] rms
CCFL Operation Current (IRCFL)	3.0	7.5		8.0		[mA] rms	2
CCFL Frequency (FCFL)	40	53		60		[KHz]	3, 4
CCFL Ignition Voltage (ViCFL, Ta= 0℃)	2000	-		-	[Volt] rms		5
CCFL Ignition Voltage (ViCF, Ta= 25℃)	1850	-		-		[Volt] rms
CCFL Operation Voltage (VCFL)	-	900		-	[Volt] rms
			(@7.5mA)				6
CCFL Power Consumption (PCFL)	-	27		-	[Watt]
CCFL Life Time (LTCFL)	40,000	50,000		-	[Hour]		7

Note 1: Typ. values are AUO recommended design values.

*1 All of characteristics listed are measured under the condition using the AUO test inverter.

*2 It is recommended to check the inverter carefully. Sometimes, interfering noise stripes appear on the screen, and substandard luminance or flicker at low power may happen.

*3 While designing an inverter, it is suggested to check safety circuit very carefully. Impedance of CCFL, for instance, becomes more than 1 [M ohm] when CCFL is damaged.

*4 Generally, CCFL has certain delay time after applying kick-off voltage. It is recommended to keep on applying kick-off voltage for 1 [Sec] until discharge.

*5 Reducing CCFL current will increase CCFL discharge voltage and generally increases CCFL discharge frequency. So all the parameters of the inverter should be carefully designed so the inverter will not produce too much leakage current from high-voltage output.

*6 Both CCFLs in the CCFL set (2 CCFL lamps on each side of a panel) is designed for identical phase driving. Reversed phase driving of CCFL set is not encouraged.

*7 For designing CCFL current, it is highly recommanded to use symmetric and consistent sinusoidal wave for each CCFL input current with asymmetric ration of 10% or less in both

postive area and negative area (ie. 0.9*√2*Irms < I1 & I2 < 1.1*√2*Irms) as refer to the following diagram, otherwise proper CCFL functionality cannot be guarantied.

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