LXMG1643-12-62 MICROSEMI, LXMG1643-12-62 Datasheet - Page 5

• Manufacturer Part Number: LXMG1643-12-62
• Description: CCFL Inverter Quad Lamp 5W 72KHz 8-Pin
• Manufacturer: MICROSEMI

Specifications of LXMG1643-12-62

• Number Of Lamps: 4
• Typical Input Voltage: 12 V
• Typical Lamp Start Voltage: 1650 Vrms
• Typical Lamp Operating Voltage: 625 Vrms
• Maximum Dimming: 50:1(Typ)
• Operating Temperature: -20 to 70 °C

Copyright © 2005
Rev. 1.1, 2006-11-16
TM
0 < P.W. < 100% of period
to 2.0V
0.45V
Figure 1A – PWM Brightness Control
Figure 2 – Maximum Output Current
PWM Signal
from System
1.8K
20K
10µs to 125µS
DAC or
Pot
(Output current set to maximum)
Figure 1 – Brightness Control
BRITE
SLEEP
SET
(SET
H
H
L
L
P.W.
LXMG1643-12-62
1
L=GND; H=Open
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: [phone]
BRITE
SET
NC
1
SLEEP
SET
and SET
H
H
L
L
LXMG1643-12-62
1
12V
2
V
SET
NC
IN1
5.0mA
6.0mA
7.0mA
8.0mA
12V
V
2
BRITE
IN1
GND
2
LXMG1643-12-62
Inputs)
GND
RMS
RMS
RMS
RMS
V
V
V
V
LOx
LOx
Hx
Hx
T Y P I C A L A P P L I C A T I O N
One of two
of two
One
Integrated Products
®
Microsemi
P
P
a
a
n
n
e
e
l
l
12V Quad 6W CCFL Programmable Inverter Module
M
M
a
a
t
t
The brightness control may be a voltage output DAC or
other voltage source, a digital pot or 20K manual pot. The
inverter contains an internal 10K pull-up to 3V to bias the
pot add a 1.8K resistor to set the lower threshold voltage.
A 3.3V Logic Level PWM signal from a micro-controller
may also be used as shown in Figure 1A.
If you need to turn the inverter ON/OFF remotely, connect
to TTL logic signal to the
Connect V
V
Never connect V
lamp current regulation. If both lamp wires have heavy
high voltage insulation, connect the longest wire to V
This wire is typically white.
Use the SET
desired maximum output current. Using these two pins in
combination allows the inverter to match a wide variety of
panels from different manufactures. Generally the best
lamp lifetime correlates with driving the CCFL at the
manufactures nominal current setting. However the SET
and SET
current to the maximum allowable output current to
increase panel brightness at the expense of some reduced
lamp life.
Although the SET pins are designed such that just leaving
them open or grounding them is all that is needed to set the
output current, they can also be actively set. Using an open
collector or open drain logic signal will allow you to
reduce the lamp current for situations where greater dim
range is required, as an example in nighttime situations. In
conjunction with a light sensor or other timer the panel
could be set to higher brightness (maximum output
current) for daytime illumination and lower brightness
(minimum or typical output current) at nighttime. Since
the dim ratio is a factor of both the burst duty cycle and the
peak output current, using this technique, the effective dim
ratio can be increased greater than the burst duty cycle
alone. Conversely the SET inputs could be used to
overdrive the lamp temporarily to facilitate faster lamp
warm up at initial lamp turn on. Of course any possible
degradation on lamp life from such practices is the users
responsibility since not all lamps are designed to be
overdriven.
The inverter has a built in fault timeout function. If the
output return is open (lamp disconnected or broken) or
shorted the inverter will attempt to strike the lamp for
several seconds. After about a second without success the
inverter will shutdown. In order to restart the inverter it is
necessary to toggle the sleep input or cycle the V
supply. In the timeout shutdown mode input drain current
will be about 8mA.
c
c
LO
h
h
™
™
to the low voltage wire (wire with thinner insulation).
P
2
RODUCTION
inputs allow the user the flexibility to adjust the
HI
1
to high voltage wire from the lamp. Connect
and SET
LO
to circuit ground as this will defeat
2
D
(see Figure 2) inputs to select the
SLEEP
ATA
S
input.
LXMG1643-12-62
HEET
IN1
input
LO
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