Microsemi

Integrated Products Division

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

Page 1

Copyright

© 2000

Rev. 1.0b, 2005-03-03

LX1993

High Efficiency LED Driver

I N T E GRA T ED

PR ODUC T S

DESCRI PTI O N

The LX1993 is a high efficiency

step-up boost converter that features a

psuedo-hysteretic pulse frequency

modulation topology for driving

white or color LEDs in backlight or

frontlight systems.

Designed for

maximum efficiency, reduced board

size, and minimal cost, the LX1993 is

ideal for PDA and digital camera

applications. The LX1993 features an

internal N-Channel MOSFET and

control circuitry that is optimized for

portable system design applications.

The LX1993 promotes improved

performance

in

battery-operated

systems by operating with a quiescent

supply current 70µA (typical) and a

shutdown current of less than 1µA.

The input voltage range is from 1.6V

to 6.0V thus allowing for a broad

selection

of

battery

voltage

applications

and

start-up

is

guaranteed at 1.6V input.

The LX1993 is capable of switching

currents in excess of 300mA and the

output current is readily programmed

using one external current sense

resistor in series with the LEDs. This

configuration provides a feedback

signal to the FB pin thus maintaining

constant output current regardless of

The LX1993 provides an additional

feature for simple dynamic adjustment

of the output current (i.e., up to 100%

of the maximum programmed current).

Designers can make this adjustment by

generating an analog reference signal

or a PWM signal applied directly to

the ADJ pin and any PWM amplitude

is readily accommodated via a single

external resistor.

The LX1993 is

available in the 8-Pin MSOP and thus

requires a very small PCB area.

IMPORTANT:

For the most current data, consult MICROSEMI’s website: http://www.microsemi.com

KEY FEATUR ES

> 80% Maximum Efficiency

70µA Typical Quiescent Supply

Current

Externally Programmable Peak

Inductor Current Limit For

Maximum Efficiency

Logic Controlled Shutdown

< 1µA Shutdown Current

Dynamic Output Current

Adjustment Via Analog

Reference Or Direct PWM Input

8-Pin MSOP Package

APPLICATIONS

Pagers

Wireless Phones

PDAs

Handheld Computers

LED Driver

Digital Camera Displays

PRODUCT H I GHLIGHT

LX1993

GND

FB

CS

SW

SHDN

IN

ADJ

OUT

ON OFF

Li-Ion

PACKAGE ORDER INFO

DU

Plastic MSOP

8-Pin

°C)

RoHS Compliant / Pb-free

Transition DC: 0432

0 to 70

LX1993CDU

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

number. (i.e. LX1993CDU-TR)