LXMG1617A-05-21 MICROSEMI, LXMG1617A-05-21 Datasheet - Page 5

• Manufacturer Part Number: LXMG1617A-05-21
• Description: CCFL Inverter Single Lamp 2.2W 90KHz
• Manufacturer: MICROSEMI

Specifications of LXMG1617A-05-21

• Number Of Lamps: Single
• Typical Input Voltage: 5 V
• Typical Lamp Start Voltage: 1200 Vrms
• Typical Lamp Operating Voltage: 380 Vrms
• Maximum Dimming: 100:1(Typ)
• Operating Temperature: -30 to 80 °C
• Lead Free Status / Rohs Status: Compliant

Copyright © 2007
Rev. 1.1, 2010-02-26
0V to
minimum
2.0V
Optional
Resistor
to adjust
dimming
level
TM
0 < P.W. < 100% of period
500k
806
DAC or
Pot
Figure 1A – PWM Brightness Control
10µs to 500µS
from System
PWM Signal
(Output current set to maximum)
Figure 2 – Max Output Current
Figure 1 – Brightness Control
BRITE
SLEEP
SET
(SET
H
H
L
L
P.W.
1
LXMG1617A-05-2x
BRITE
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: [phone]
L=GND; H= Open
SET
NC
SLEEP
1
SET
1
and SET
LXMG1617A-05-2x
H
H
L
L
2
5V
SET
V
NC
IN
3.5mA
4.0mA
4.5mA
5.0mA
2
5V
V
GND
BRITE
IN
2
LXMG1617A-05-2x
Inputs)
GND
RMS
RMS
RMS
RMS
V
V
LO
HI
V
V
T Y P I C A L A P P L I C A T I O N
LO
HI
CCFL
TUBE
Analog Mixed Signal Group
TUBE
CCFL
®
Microsemi
PanelMatch™
5V 2.2W CCFL Programmable Inverter Module
The brightness control may be a voltage output DAC or other
voltage source, a digital pot or 500k manual pot. The inverter
contains an internal 215k pull-up to 3V to bias the pot, it may
be necessary to add a small value resistor in series with the
ground side of the POT to set the lower threshold voltage
above the absolute minimum dim level capability, especially
when both SET pins are programmed low. A PWM logic level
signal (figure 1A) may be used up to 5V; however the inverter
will reach maximum current at less than 100% duty cycle.
This can be calculated as approximately 2V divided by the
logic high voltage level; with 3.3V logic level this corresponds
to about 60% duty cycle for maximum lamp current.
If you need to turn the inverter ON/OFF remotely, connect to
TTL logic signal to the
Connect V
to the low voltage wire (wire with thinner insulation). Never
connect V
regulation.
insulation, connect the longest wire to V
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 manufacturers. Generally the best lamp
lifetime correlates with driving the CCFL at the manufacture’s
nominal current setting. However the SET
allow the user the flexibility to adjust the 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 user’s 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 up to about one second, after
which (without success) the inverter will shutdown, in this
mode the inverter will draw about 8mA from V
restart the inverter it is necessary to toggle the sleep input or
cycle the V
P
"
"
RODUCTION
LO
HI
A
IN
A
to high voltage wire from the lamp. Connect V
to circuit ground as this will defeat lamp current
If both lamp wires have heavy high voltage
1
input supply.
S
S
and SET
e
e
r
r
i
i
e
e
SLEEP
s
s
2
D
"
"
(see Figure 2) inputs to select the
ATASHEET
input.
LXMG1617A-05-2x
LO
1
and SET
.
IN
This wire is
. In order to
2
inputs
Page 5
LO