Acer 1800 - Manual (Page 37)

Chapter 1 29
NOTE:
*1. The display can not happen flicker or shutdown.
*2. Limited lamp maximum current by DAC_BRIC signal:
DAC_BRIG signal comes from system with internal resistance of 3K .
When add 1V DAC, the 100% Lamp current will decrease 0.5mA.
*3. Inverter operating frequency should be within specification (50~70kHz) at max. and min.
brightness load.
*4. 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 40%.
*5.The system interface signals belong to 3.3V.
*6. Please make sure open lamp output voltage should be within starting voltage specification.
*7. Inverter should pass human body safety test.
*8. Inverter should be no smoking by any component open/short test.
*9. Transformer voltage stress should not be over 85% under any condition.
(turn on overshoot transient and line transient.)
*10. Inverter should without acoustic 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 should follow below:
T
∆T <=40 C, at 25 C and without airflow.
T
Component temperature can’t the Bezel deformed of system.
Lamp limited current DAC_BRIG INV_PWM
Max. 0V 100%
Min. 3.3V 100%
Electrical specification
No
.
Symbol Min. Typ. Max. Unit Comment
1
V oper* -- 785 -- Vrms Lamp operating voltage
IL 6.2 6.5 6.8 mArms DAC_BRIG: 0 V, PWM:
100%
IL 3.3 3.6 3.9 mArms DAC_BRIG: 0 V,
PWM:40%
IL 5.7 6.0 6.3 mArms DAC_BRIG: 0.5V,
PWM:100%
IL 3 3.3 3.6 mArms DAC_BRIG: 0.5V,
PWM:40%
f 50 60 70 kHz
76% -- -- --
Ω
η
° °