Inverter Interface Characteristics - Akai LCT32AD Service Manual

condition at 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.
Note (6) To enhance the performance of backlight, the power consumption will increase to 1.5 times of the
typical power consumption P
value. Thus, the power source capacity for inverter should be considered to supply the initial
power consumption at power on duration.

3.2.3 INVERTER INTERFACE CHARACTERISTICS

Parameter
On/Off Control ON
Voltage
OFF
Internal/External HI
PWM Select Voltage
LO
Internal PWM MAX
Control Voltage
MIN
External PWM HI
Control Voltage
LO
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.
Note (2) The power sequence and control signal timing are shown as the following figure.
= 4.0 ~ 5.0 mA
L
in the power on stage and 20 seconds later it will return to typical
BL
Test
Symbol
Condition
Min.
－
2.0
V
BLON
－
－
2.0
V
SEL
－
V V = L
IPWM SEL
2.0
V V = H
EPWM SEL
－
T
r
－
T
f
－
T
PWMR
－
T
PWMF
－
R
IN
－
T 500
on
－
T 500
off
86／129
.
RMS
Value
Unit
Typ. Max.
－
5.0 V
－
0 0.8 V
－
5.0 V
－
0 0.8 V
－ －
3.0 V
－ －
0 V
－
5.0 V
－
0 0.8 V
－ －
100 ms
－ －
100 ms
－ －
50 us
－ －
50 us
－ －
1 MΩ
－ －
ms
－ －
ms
. Since
BL
Note
minimum duty ratio
maximum duty ratio
duty on
duty fff