P
A T E N T
P
E N D I N G
LIN D
O C
#:
1653
LXM1653-01
F
LOAT I N G
O
U T P U T
D
RIV E
, CCFL I
NVER TER
M
O D U L E S
T
H E
I
N F I N I T E
P
O W E R
O F
I
N N O VA T I O N
P
R E L I M I N A R Y
D
A T A
S
H E E T
DESCRIPTION
The LXM1653 floating output drive
CCFL (Cold Cathode Fluorescent Lamp)
Inverter Module is specifically designed
to drive large LCD displays (11.3" and
larger), which are used in notebook
computers. This new inverter was
specifically designed to reduce the
leakage currents from the lamp to the
reflector or the metal frame of the
panels. The floating output architec-
ture of this inverter also permits a
much wider dimming range when
compared to non-floating designs, and
allows an additional 10% efficiency
improvement.
The module converts unregulated
DC voltage from the system battery or
AC adapter directly to high-frequency,
high-voltage sine waves required to
ignite and operate CCFL lamps. The
module design is based on a propri-
etary Linfinity IC that provides impor-
tant new performance advances.
Remarkable improvements in
efficiency and RF emissions result from
this
single
stage resonant inverter,
featuring a patented Current Synchro-
nous, Zero Voltage Switching (CS-ZVS)
topology. CS-ZVS produces nearly
pure sine wave currents in the lamp,
enabling maximum light delivery, while
reducing both conducted and radiated
noise. This topology simultaneously
performs two tasks including line
voltage regulation and lamp dimming
through lamp current regulation.
These two functions are performed in
a single power stage made up of a pair
of low-loss MOSFETs. The MOSFETs
drive a low current resonant circuit that
feeds the primary of a high-voltage
transformer with a sinusoidal voltage.
Required L and C values in the
resonant circuit are such that very low-
loss components can be used to obtain
higher electrical efficiency than is
possible with previous topologies.
The full-bridge LXM1653 provides
peak efficiency when operated at input
voltages from 6.5 volts to 18 volts.
In addition, this module is equipped
with a dimming input that permits full
range brightness control from an
external potentiometer or PWM signal,
and a sleep input that reduces module
power to a few microwatts in shut-
down mode.
Output open and short circuit
protection are also featured on this
module.
K E Y F E AT U R E S
s
FULLY FLOATING OUTPUT
s
35% MORE LIGHT OUTPUT AT 5 WATTS
s
GREATER EFFICIENCY THAN GROUNDED
OUTPUT DESIGNS
s
s
s
s
6.5V TO 18V INPUT VOLTAGE RANGE
VERSATILE BRIGHTNESS CONTROL INPUT
10 MICROAMP SLEEP CURRENT
OUTPUT SHORT CIRCUIT PROTECTION AND
AUTOMATIC OVER VOLTAGE LIMITING
s
7.4mm MAX HEIGHT, NARROW FOOTPRINT
s
MINIMIZE THERMOMETER EFFECTS
s
MINIMIZE LAMP TO PANEL LEAKAGE
CURRENT
A P P L I C AT I O N S
s
11.3" LCD PANELS AND LARGER
s
NOTEBOOK AND SUB-NOTEBOOK
COMPUTERS
s
PORTABLE INSTRUMENTATION
s
AUTOMOTIVE DISPLAYS
s
DESKTOP DISPLAYS
s
AIRLINE ENTERTAINMENT CENTERS
BENEFITS
s
ULTRA-HIGH EFFICIENCY, LINE VOLTAGE
REGULATION AND SLEEP MODE EXTEND
COMPUTER BATTERY LIFE
s
COOL OPERATION PERMITS CLOSE
PROXIMITY TO LCD PANEL WITHOUT
DISPLAY DISTORTION
s
SMOOTH, FULL-RANGE BRIGHTNESS
CONTROL GIVES YOUR PRODUCT A HIGH
QUALITY IMAGE
s
LOW EMI / RFI DESIGN MINIMIZES
SHIELDING REQUIREMENTS
s
NARROW, LOW-PROFILE MODULE FITS
INTO MOST LCD ENCLOSURES
PRODUCT HIGHLIGHT
F
LOATING
O
UTPUT
A
RCHITECTURE
High Voltage
Transformer
CS-ZVS
Inverter
DC V
IN
MODULE
ORDER
CCFL
INFO
FULL-BRIDGE DRIVE
LXM1653-01
F O R F U R T H E R I N F O R M AT I O N C A L L ( 7 1 4 ) 8 9 8 - 8 1 2 1
Copyright 漏 1997
Rev. 0.1 3/97
11861 W
ESTERN
A
VENUE
, G
ARDEN
G
ROVE
, CA. 92841
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