LX1994
TM
庐
High Efficiency LED Driver
P
RODUCTION
D
ATA
S
HEET
DESCRIPTION
KEY FEATURES
Efficiency > 92%
Dual PFM Architecture To
Extend Battery Life
V
IN
Range 2.0V To 5.5V. Start
Up Warranty @ 2.0V
Logic Control Shutdown
100碌A Typical Quiescent
Current
Shutdown I
Q
Current <1碌A
OVP For Open String Output
Voltage
Low Voltage And Offset
Current Sense
Light Sensor (LX1970)
interface
Dual Dimming Options (PWM
or DC Voltage)
No External Zener Clamp
Diode
10-Pin MLP or MSOP
APPLICATIONS
Microsemi鈥檚 LX1994 is a compact,
high efficiency, step-up boost
controller which is designed to drive a
string of white or colored LED鈥檚 in a
backlight or front light system. The
LX1994 design is based on a dual
mode PFM architecture and provides
maximum typical efficiency greater
than 92%.
The LX1994 has many unique
design features and advantages over
competitor solutions. The features
included:
low quiescent current
(100碌A typical), low shut down
current (<1碌A), dedicate ambient light
sensor interface (LX1970), dual
dimming modes, low voltage and low
offset current sense, and integrated
OVP protection.
The converter achieves high
efficiency, low cost, and flexible
design by selection of an external N-
Channel MOSFET, current sense
resistors,
and
integrated
OVP
protection.
The use of external N-channel
MOSFET allows design to optimize
system efficiency.
The OVP protection comparator
eliminates the need of an external Zener
diode clamp. The OVP function can be
scaled for any output voltage.
Maximum output current is achievable
by selection of the current sense
resistor.
These features make the
controller ideal for PDA or digital
camera applications
To enhance system battery life, the
LX1994 provides 2 dimming options
and a dedicated ambient light sensor
(LX1970) interface.
The LX1994 supports a wide range
of system battery voltage inputs which
ranges from 2.0 to 5.5V. The LX1994
is guaranteed to start up at 2.0V input.
The LX1994 is available in miniature
10-pin MLP or MSOP packages.
WWW .
Microsemi
.C
OM
IMPORTANT:
For the most current data, consult
MICROSEMI鈥檚
website:
http://www.microsemi.com
Pagers
PDA
Cell Phone
Portable Display
Digital Cameras
PRODUCT HIGHLIGHT
33碌H
V
IN
= 2.0V to 5.5V
UPS5819
Auto Adjust for
Ambient Light
3V
VDD
VSS
SNK
SRC
VIN
S/P
LX1994
FDV303
DRV
SRC
OVP
FB
BRT
LS
GND
LX1970
CMP
LX1994
LX1994
PACKAGE ORDER INFO
T
A
(掳C)
-40 to 85
Plastic MLP
LD
10-Pin
LX1994CLD
Plastic MSOP
DU
10-Pin
LX1994CDU
Note: Available in Tape & Reel. Append the letters 鈥淭R鈥?to the part number. (i.e.
LX1994CDU-TR)
Copyright
漏
2003
Rev. 1.0a, 2004-08-10
Microsemi
Integrated Products Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
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