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Doc.No
Rev.No
04 - 000 - G - 010515
Page
LTM150XH-L01
/
35
12
Approval
3.2 BACK-LIGHT UNIT
Ta= 25
±
2
°
C
Note
.
LCD
MODULE
INVERTER
A
HOT 1 ( Pink )
1
2
COLD ( White )
ITEM SYMBOL MIN TYP MAX UNIT NOTE
Lamp Current
3.0
6.0
(1)
mA
rms
Lamp Voltage
Lamp Frequency
40
60
-
V
rms
kHz
(2)
Operating Life Time
of Lamp
25,000
Hour
35,000
-
665
-
6.5
-
(2) Lamp frequency may produce interference with horizontal synchronous frequency and this
may cause line flow on the display. Therefore lamp frequency shall be detached from the
horizontal synchronous frequency and its harmonics as far as possible in order to avoid interference.
(3) Life time (Hr) of a lamp is defined as the time in which it continues to operate under the
condition of Ta = 25
±
2
°
C and I
L
= 6.0 mArms until the brightness becomes 50% or lower than
it’s original value.
(4) The voltage above this value should be applied to the lamps for more than 1 second to startup.
Otherwise the lamps may not to be turned on.
(3)
The back-light system is an edge-lighting type with 4 CCFTs(Cold Cathode Fluorescent Tube).
The characteristics of four lamps are shown in the following tables.
Startup Voltage
1020 (25
°
C)
1430 (0
°
C)
Vrms
(4)
Vs
-
-
The performance of the back-light, for example life time or brightness, is much influenced by the
characteristics of the DC-AC inverter for the lamp. So all the parameters of an inverter should be carefully
designed so as not to produce too much leakage current from high-voltage output of the inverter.
When you design or order the inverter, please make sure that a poor lighting caused by the mismatch of
the back-light and the inverter(miss lighting, flicker, etc.) never occur. When you confirm it, the module
should be operated in the same condition as it is installed in your instrument.
V
L
I
L
Hr
F
L
Note) The waveform of the inverter output voltage must be area symmetric and the design of the
inverter must have specifications for the modularized lamp.
I
L
=6.0
mArms