Microsemi
Integrated Products Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 1
Copyright
2000
Rev. 1.1, 2002-11-21
W
M
.
C
LX1741
High Efficiency High Voltage Boost Controller
P
RODUCTION
D
ATA
S
HEET
I N T E G R A T E D P R O D U C T S
D E S C R I P T I O N
The LX1741 is a compact high
efficiency step-up boost controller.
Featuring a pseudo-hysteretic pulse
frequency modulation topology, the
LX1741 was designed for maximum
efficiency, reduced board size, and
minimal cost.
Utilizing an external N-Channel
MOSFET,
the
designers maximum flexibility with
respect to efficiency and cost. The
LX1741 provides several design
enhancements that improve overall
performance under very light load
currents by implementing control
circuitry that is optimized for portable
systems - thus providing a quiescent
supply current of only 80μA (typ) and
a shutdown current of less than 1μA.
The input voltage ranges from 1.6V
to 6.0V, allowing for a wide selection
of system battery voltages. Start-up
LX1741
offers
operation is guaranteed at 1.6V input
The output voltage is programmed
easily using two external resistors in
conjunction with the feedback pin.
Depending on the MOSFET selected,
the LX1741 is capable of achieving
output voltages much higher than 40V.
The LX1741 has an additional feature
for simple dynamic adjustment of the
output voltage (i.e., up to
±
15% of the
nominal output voltage). Voltage
adjustment is achieved via an analog
reference signal or a direct PWM input
signal applied to the ADJ pin. Any
PWM amplitude is easily accom-
modated with a single external resistor.
The LX1741 is available in both the 8-
Pin MSOP, and the miniature 8-Pin MLP
requiring minimal PCB area.
IMPORTANT:
For the most current data, consult
MICROSEMI
’s website:
http://www.microsemi.com
K E Y F E A T U R E S
> 85% Maximum Efficiency
80μA Typical Quiescent Supply
Current
Externally Programmable Peak
Inductor Current Limit For
Maximum Efficiency
Logic Controlled Shutdown
< 0.5 μA Shutdown Current (typ)
Dynamic Output Voltage
Adjustment Via Analog Reference
Or Direct PWM Input
8-Pin MSOP Package or 8-Pin
MLP
APPLICAT IONS /BENEFIT S
Pagers
Wireless Phones
PDAs
Handheld Computers
General LCD Bias Applications
LED Driver
P R O D U C T H I G H L I G H T
C
1
4.7
μ
F
R
CS
1k
L
1
47
μ
H
1206 Case Size
V
BAT
= 1.6V to 6.0V
ON OFF
V
LCD
= 18V ± 15%
LX1741
GND
SHDN
IN
ADJ
FB
CS
NDRV
SRC
PACK AGE ORDER INFO
Plastic MLP
8-Pin
LX1741CLM
Note: Available in Tape & Reel.
Append the letter “T” to the part number. (i.e. LX1741CDUT)
T
A
(
°
C)
LM
DU
Plastic MSOP
8-Pin
LX1741CDU
0 to 70
L
X
1
7
4
1