LXM1623-12-61 データシートの表示（PDF） - Microsemi Corporation
部品番号
コンポーネント説明
メーカー
LXM1623-12-61 Datasheet PDF : 6 Pages
| |||
PanelMatch™
LXM1623-12-6x
INTEGRATED PRODUCTS
12V Dual 6W Programmable CCFL Inverter Module
PRODUCTION DATASHEET
TYPICAL APPLICATION
DAC or
Pot
BRITE
12V
V IN 1
0.45V 20K
to 2.0V
1.8K
VHI
LXM1623-12-6x
CCFL
TUBE
SLEEP
SET1 SET2
NC
NC
VLO
GND
ONE OF
TW O
Figure 1 – Brightness Control
(Output current set to maximum)
PW M Signal
from System
BRITE
P.W .
LXM1643-12-6x
10us to 125uS
0 < P.W. < 100% of period
Figure 1A – PWM Brightness Control
12V
BRITE
V IN 1
VHI
LXM1623-12-6x
SLEEP
SET1 SET2
GND
CCFL
TUBE
VLO
ONE OF
TW O
L
L
5.0mARMS
L
H
6.0mARMS
H
L
7.0mARMS
H
H
8.0mARMS
L=GND; H=Open
Figure 2 – Max Output Current
(SET1 and SET2 Inputs)
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 SLEEP input.
Connect VHI to high voltage wire from the lamp. Connect
VLO to the low voltage wire (wire with thinner insulation).
Never connect VLO to circuit ground as this will defeat
lamp current regulation. If both lamp wires have heavy
high voltage insulation, connect the longest wire to VLO.
This wire is typically white.
Use the SET1 and SET2 (see Figure 2) inputs to select the
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 SET1
and SET2 inputs 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 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 to 4 seconds without success the
inverter will shutdown. In order to restart the inverter it is
necessary to toggle the sleep input or cycle the VIN1 input
supply
Copyright © 2002
Rev. 1.0b, 2005-01-20
Microsemi
Integrated Products
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 5
Share Link: 