Acer 270 User Manual
Page 37
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Chapter 1
When DAC_BRIG voltage is 0V and INV_PWM enables (100%), lamp has max. current.
When DAC_BRIG voltage is 3.3V and INV_PWM enables (100%), lamp has min. current.
DAC_BRIG signal comes from system chipset with internal resistance of 3K
*2. Inverter operating frequency should be within specification (45~65kHz) at max. and min.
brightness load.
*3. INV_PWM enable implies INV_PWM signal is High level (On duty cycle is 100%). It is a square
wave of 150Hz to adjust backlight brightness that is a function of PWM duty cycle. Backlight
brightness is maximum value under INV_PWM at 100% and brightness is minimum under
INV_PWM at 30%.
*4.The system interface signals belong to 3.3V.
*5. Please make sure open lamp output voltage should be within starting voltage specification.
*6. Inverter should pass human body safety test.
*7. Inverter should be no smoking by any component open/short test.
*8. Transformer voltage stress should not be over 85% under any condition.
(turn on overshoot transient and line transient.)
*9. Audio noise should be less than 36dB at 10cm distance.
.
Thermal
All components on inverter board should follow below rules:
1. Component using conditions (component stress) must be within component specification including voltage
rating, current rating, temperature etc.
2. Component temperature shold follow below:
❑
∆
T <=30 degree C, at 25, 35 degree C.
❑
Component temperature should be less than 70 degree C inside system at 35 degree C.
Electrical specification
No
.
Symbol
Min.
Typ.
Max.
Unit
Comment
1
V oper*
--
700
--
Vrms
Lamp operating voltage
Il
5.7
6.0
6.3
mArms
DAC_BRIG: 0V,
PWM:100%
Il
2.7
3.0
3.3
mArms
DAC_BRIG: 0V,
PWM:30%
F
45
55
65
kHz
η
80%
--
--
--
LCD
Item
Specification
Vendor & model
name
AU UB
141X03
Samsung
LTN141XF-
L05
Hannstar
HSD150PXII-
B
Hannstar
HSD150PKII-
B
IBM ITUX97C
Mechanical Specifications
LCD display area
(diagonal, inch)
14.1
14.1
15.0
15.0
15.0
Display technology
TFT
TFT
TFT
TFT
TFT
Resolution
XGA
(1024x768)
XGA
(1024x768)
XGA
(1024x768)
SXGA+
(1400x1050)
UXGA
(1600X1200)
Ω
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