LXMG1624-12-42 MICROSEMI, LXMG1624-12-42 Datasheet - Page 5

• Manufacturer Part Number: LXMG1624-12-42
• Manufacturer: MICROSEMI

Specifications of LXMG1624-12-42

• Operating Temperature Classification: Commercial
• Mounting: Surface Mount
• Pin Count: 12
• Lead Free Status / RoHS Status: Compliant

Copyright © 2005
Rev. 1.1, 2006-11-16
TM
20K
Rx*
DAC or
Pot
*Set Rx from 2.7K to 3.9K depending on panel
26% > P.W. < 100% of
Figure 1A – PWM Brightness Control
Figure 2 – Maximum Output Current
(Output current set to maximum)
minimum lamp current requirements
from System
10us to 125uS
PWM Signal
Figure 1 – Brightness Control
BRITE
SLEEP
SET
period
(SET
H
H
L
L
BRITE
SET
NC
SLEEP
P.W.
1
LXMG1624-12-4x
L=GND; H=Open
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: [phone]
1
1
LXMG1624-12-4x
SET
and SET
H
H
L
L
SET
NC
12V
2
V
12V
V
2
IN1
IN1
5.0mA
5.5mA
6.0mA
6.5mA
BRITE
LXMG1624-12-4x
GND
2
GND
Inputs)
RMS
RMS
RMS
RMS
V
V
V
V
LO
LO
HI
HI
ONE OF
ONE OF
T Y P I C A L A P P L I C A T I O N
TWO
TWO
CCFL
TUBE
CCFL
TUBE
Integrated Products
®
Microsemi
PanelMatch™
12V Dual 4W CCFL Programmable Inverter Module
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 2.7K to 3.9K 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 a 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 is open (lamp disconnected or broken) or shorted
the inverter will attempt to strike the lamp for several
seconds. After about 2 seconds without success the inverter
will shutdown.
necessary to toggle the sleep input or cycle the V
supply
LO
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
In order to restart the inverter it is
to circuit ground as this will defeat
2
D
(see Figure 2) inputs to select the
SLEEP
ATA
S
input.
LXMG1624-12-4x
HEET
IN1
input
LO
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