Microsemi

Integrated Products Division

11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570

Page 1

Copyright

© 2000

Rev. 1.1b, 2005-03-03

LX1741

High Efficiency High Voltage Boost Controller

I N T E GRA T ED

PR ODUC T S

DESCRI PTI 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

LX1741

offers

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

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

KEY FEATUR ES

> 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

APPLICATIONS/BENEFITS

Pagers

Wireless Phones

PDAs

Handheld Computers

General LCD Bias Applications

LED Driver

PRODUCT H I GHLIGHT

C

1

4.7µF

R

CS

1kΩ

L

1

47µH

1206 Case Size

V

ON OFF

V

LX1741

GND

SHDN

IN

ADJ

FB

CS

NDRV

SRC

PACKAGE ORDER INFO

LM

Plastic MLP

8-Pin

DU

Plastic MSOP

8-Pin

°C)

RoHS Compliant / Pb-free

Transition DC: 0452

RoHS Compliant / Pb-free

Transition DC: 0432

0 to 70

LX1741CLM

LX1741CDU

Note: Available in Tape & Reel. Append the letters “TR” to the part number. (i.e.

LX1741CDU-TR)