LQ121S1DG42 Sharp Microelectronics, LQ121S1DG42 Datasheet - Page 9

• Manufacturer Part Number: LQ121S1DG42
• Description: TFT Displays & Accessories 12.1 TFT 800xRGBx600
• Manufacturer: Sharp Microelectronics

Specifications of LQ121S1DG42

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

7-2. Backlight driving
[Note1] Lamp current is measured with current meter for high frequency as shown below.
[Note2] Referential data per one CCFT by calculation. (I L × VL)
[Note3] Lamp frequency may produce interference with horizontal synchronous frequency,and this may cause beat
[Note4] The open output voltage of the inverter shall be maintained for more than 1s; otherwise
[Note5] Lamp is consumables. In the following condition, the life time is 50,000 hour as the reference value and it is not
[Note6] The performance of the backlight, for example life time or brightness, is much influenced by the
[Note7] It is required to have the inverter designed so that to allow the impedance deviation of the two CCFT lamps
[Note8] Under the environment of 10 lx or less, lamp may not turn on or it may take some time to turn on.
The backlight system is an edge-lighting type with double CCFT (Cold Cathode Fluorescent Tube).
The characteristics of single lamp are shown in the following table.
(It is usually required to measure under the following condition.
Parameter
Lamp current
Lamp power consumption
Lamp frequency
Kick-off voltage
condition:IL=6.0mA,Ta=25℃±2℃,FL=60kHz.)
Above value is applicable when lamp is placed horizontally.
Lamp life time is defined that it applied either ① or ② under this condition
The data don’t include loss at inverter. ( IL=6.0mArms)
on the display. Therefore lamp frequency shall be detached as much as possible from the horizontal
synchronous frequency and from the harmonics of horizontal synchronous to avoid interference.
guaranteed in this technical literature sheet by SHARP.
characteristics of the DC-AC inverter for the lamp. When you design or order the inverter,
please make sure that a poor lighting caused by the mismatch of the backlight 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.
Be sure to use a back light power supply with the safety protection circuit such as the detection circuit
for the excess voltage, excess current and or electric discharge waveform.
Be sure to use the detect circuit by which one side of the CCFT lamps can be controlled independently.
Otherwise, when one side of the CCFT is open, the excess current may possibly be applied to the other side
of the lamp.Recommended inverter is “CXA-P1212B-WJL(TDK corporation)”.
and the capacity deviation of barast capacitor.
In case of operating under lower temp environment, the lamp exhaustion is accelerated and the
brightness becomes lower. (Continuous operating under for around 1 month under lower temp
In case of such usage under lower temp environment, periodical lamp exchange is recommended.
(Lamp life time may vary if lamp is in portrait position due to the change of mercury density inside
the lamp.) Lamp life time shortens according to the state of mounting and use.
condition may reduce the brightness to half of the original brightness.)
the lamp may not be turned on.
(Continuous turning on at Ta=25
① Brightness becomes 50% of the original value under standard condition.
② Kick-off voltage at Ta=-10
Module
１
１
* 3pin is V
3
3
Symbol
PL
FL
Vs
IL
o
C exceeds maximum value,1500Vrms.
o
C, IL=6.0mArms)
Ａ
∼
Ａ
∼
3.0
35
-
-
-
-
LOW
Typ.
6.0
3.5
60
-
-
-
Inverter
Max.
1200
1400
1500
6.5
80
-
mA rms
V rms
V rms
V rms
Unit
kHz
W
Remark
[Note1]
[Note2]
[Note3]
Ta=25
Ta=0
Ta=-10
o
C [Note4]
o
o
C
C