Akai LCT2785TA, Руководство по обслуживанию

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Note (4) The life time of a lamp is defined as when the brightness is larger than 50% of its original value
and the effective discharge length is longer than 80% of its original length (Effective discharge
length is defined as an area that has equal to or more than 70% brightness compared to the
brightness at the center point.) as the time in which it continues to operate under the condition Ta
= 25
±
2
℃
and I
L
= 4.2 ~ 5.2 mA
RMS
.
Note (5) The power supply capacity should be higher than the total inverter power consumption P
BL
. Since
the pulse width modulation (PWM) mode was applied for backlight dimming, the driving current
changed as PWM duty on and off. The transient response of power supply should be considered
for the changing loading when inverter dimming.
3.2.3 INVERTER INTERTFACE CHARACTERISTICS
Item Symbol
Test
Condition
Min. Typ. Max. Unit Note
ON
－
2.0
－
5.0 V
On/Off Control
Voltage
OFF
V
BLON
－
0
－
0.8 V
HI
－
2.0
－
5.0 V
Internal/External
PWM Select Voltage LO
V
SEL
－
0
－
0.8 V
MAX
－ －
3.0 V minimum duty ratio
Internal PWM
Control Voltage
MIN
V
IPWM
V
SEL
= L
－
0
－
V maximum duty ratio
HI 2.0
－
5.0 V duty on
External PWM
Control Voltage
LO
V
EPWM
V
SEL
= H
0
－
0.8 V duty off
Control Signal Rising Time T
r
－ － －
100 ms
Control Signal Falling Time T
f
－ － －
100 ms
PWM Signal Rising Time T
PWMR
－ － －
50 us
PWM Signal Falling Time T
PWMF
－ － －
50 us
Input impedance R
IN
－
1
－ －
M
Ω
BLON Delay Time T
on
－
1
－ －
ms
BLON Off Time T
off
－
1
－ －
ms
Note (1) The SEL signal should be valid before backlight turns on by BLON signal. It is inhibited to change
the internal/external PWM selection (SEL) during backlight turn on period.
Version 1.0
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