Acer Aspire 2000 Aspire 2000 Notebook Service Guide - Page 37

No Paramete . r Symbol 15 Turn off Voff voltage (Low side) Min. -- Typ. -- Max. 150Vp -p Unit V Comment PWM=30% 16 Voltage Trise -- -- 300us us PWM=30% Rise time (Low side) 17 Voltage Tfall -- -- 300us us PWM=30% fall time (Low side) NOTE: *1. The inverter can work in 7.5V input voltage (continuous), but 7.5V electronic characteristic will not be care. *2. Limited lamp maximum current by DAC_BRIC signal: 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. When add 1V DAC, the 100% Lamp current will decrease 0.5mA. DAC_BRIG signal comes from system chipset with internal resistance of 3K Ω *3. Inverter operating frequency should be within specification (45~65kHz) 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 30%. *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. Audio noise should be less than 36dB at 10cm distance. 30 Chapter 1