Acer TravelMate -550, Service Manual

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30 Chapter 1
*7. Audio noise: less than 36db@10cm distance
NOTE: *8. Wave form requirement: 1.27<=Ip/Irms<=1.8
This Inverter is desigened for the CCFL of
α
550 15.1” LCD which are using on the
α
550 notebook. We use
PWM duty to control the LCD brightness.
Features
1. +5V fixed input voltage
2. Brightness adjustment by PWM duty cycle.
3. Build with Current limited function and open lamp protection function, meet with safety requirement.
LCD Inverter Specification FOR 15.0”
Panel Lis
No. LCD Type Vendor Model No.
Frequency range
Min./Typ./Max
Lamp current
(mArms)
Min/Typ/Max
15.0” XGA TFT LG LP150X1-
G2CP (XGA
TFT) 40/60/80KHz 3.0/6.0/8.0mA
15.0” SXGA
TFT IBM ITSX95C 40/.../60KHz 3.0/6.5/7.0mA
Inverter Characteristics
No
.
Parameter Symbol Min. Typ. Max. Unit Conditions
1 Input
voltage Vin 4.7 4.8 4.9 V
2 Input
current Iin -- --- 1.2 A
3
Lamp
Current ILmas 5.5 5.75 6.0 mArms Enable= H,
PWM Duty = 100%
3.0 mArms Enable = H,
PWM Duty = 30%
4
Lamp
voltage
VL --
690
--
Vrms
At IL = 5.5 mArms
5 Frequency F 45 55 65 kHz *2
6 Output
power Pout -- -- 4.6 W
7 Efficiency
η
80 85 -- %
8 Starting
voltage Vs 1550 Vrms At 0 degree C
9 Enable VIH 2.4 -- -- V Compal Output H: 3.3V
Compal Output L: 0V
VIL -- -- 0.8 V
10 PWM
signals *3 -- 150 -- Hz PWM signal frequency
VIH 2.4 V Compal OUtput H: 5.0V
VIL 0.8 V Compal Output L: 0V
30 -- 100 %