Hitachi CML153, Service Manual

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16
7. VP-531 POWER BOARD
A. Description
The VP-531 power board is designed for lighting up the back-lights of LCD module.
B. Electrical characteristics
B-1 FOR HANNSTAR PANEL
MIN. TYP. MAX. COMMENT
INPUT VOLTAGE 11.4V 12V 12.6V
INPUT CURRENT -------- 0.85A 1A
Vin=12V MAX.
BRIGHTNESS
NO LOAD BACKLIGHT
VOLTAGE
-------- 640V rms. --------
LAMP CURRENT 3mA rms. 6mA rms. 7mArms
DRIVING FREQUENCY 40KHz 55KHz 70KHz
EFFICIENCY -------- 75% -------- Vin = 12V
Operating Life Time 50,000 ------- -------- Hours (noto)
Note:
Life time(Hr) can be defined as the time in which it continues to operate under the
condition:
Ta=25
±
3
°
C, I
L
=6.0Ma(ms) and f
L
=30 KHz until one of the following event occurs:
1. When the brightness becomes 50%
2. When the startup voltage (Vs) at 0
°
C becomes higher than the maximal value of
Vs specified above
B-2 DC/DC power
B.2.1 Input
12V ±5% from adaptor
B.2.2 Output
Item Output voltage max. load Min. load tolerence ripple & noise(max.)
Vcc 5V 1.2A 0.1A ±5% 150Vpp
B.2.3 Efficiency:78% typ. at maximum load.