Acer TravelMate 270 TravelMate 270 Service Guide - Page 36

3. Automatic brightness compensation for input voltage variation. Electrical Characteristics No . Parameter Symbol Min. Typ. Max. Unit 1 Input NV_PWR 9 14.8 voltage 2 Input Iin -- 0.33 current 3 Lamp IL 2.7 -- current 4 Frequency F 45 55 5 Output Pout -- -- power 6 Efficiency η 80% -- 7 Starting Vs voltage 1600 -- 8 Starting Tvs 1 -- time 9 Dispoff# 2.8 3.3 0 0.5 10 Limited DAC- 0 lamp BRIG maximum current 11 PWM INV_PW 142 150 signal M *Note 4 3.0 3.3 30 -- 21 V -- A 6.3 mA 65 KHz 4.5 W -- -- --- V 1.5 Sec 3.6 V 0.8 V 3.3 V 158 Hz 3.6 V 100 % 12 Lamp I zero-PK -- current over-shoot 13 Current Waveform factor 1.27 Ip I rms -- 10 1.56 2 14 Unbalance -10% 0 Rate Ip −I−p Irms +10% 15 Turn off Voff -- -- 100Vp- voltage P 16 Voltage Trise -- -- 300us Rise time 17 Voltage fall Tfall -- -- 300us time NOTE: Please pay attention to the fellowing: *1. Limited lamp maximum current by DAC_BRIC signal: % Multiple Mulitple V us us Comment *Note 1 * Note 2 At 0'C Backlight on/off signal Low level *Note 1 PWM signal frequency PWM signal amplitude Duty = ----T-----o---n-----Period Line transient (10.8V to 21V/100us) and turn on transient I−p or I rms *10 PWM=40% PWM=40% PWM=40% Chapter 1 31