Inverter Intertface Characteristics - Akai lct2785ta Service Manual

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
Note (5) The power supply capacity should be higher than the total inverter power consumption P
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
On/Off Control
Voltage
Internal/External
PWM Select Voltage
MAX
Internal PWM
Control Voltage
External PWM
Control Voltage
Control Signal Rising Time
Control Signal Falling Time
PWM Signal Rising Time
PWM Signal Falling Time
Input impedance
BLON Delay Time
BLON Off Time
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.
= 4.2 ~ 5.2 mA .
L RMS
Test
Symbol
Condition
－
ON
V
BLON
－
OFF
－
HI
V
SEL
－
LO
V V
IPWM SEL
MIN
HI
V V
EPWM SEL
LO
－
T
r
－
T
f
－
T
PWMR
－
T
PWMF
－
R
IN
－
T
on
－
T
off
Min. Typ.
－
2.0
－
0
－
2.0
－
0
－ －
= L
－
0
－
2.0
= H
－
0
－ －
－ －
－ －
－ －
－
1
－
1
－
1
39
Max. Unit
5.0 V
0.8 V
5.0 V
0.8 V
3.0 V minimum duty ratio
－
V maximum duty ratio
5.0 V duty on
0.8 V duty off
100 ms
100 ms
50 us
50 us
－
MΩ
－
ms
－
ms
. Since
BL
Note
Version 1.0