Microsemi

Linfinity Microelectronics 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

LX1992

High Efficiency LED Driver

TM

®

DESCRI PTI O N

The LX1992 is a compact high

efficiency step-up boost controller for

driving white or color LEDs in

backlight or frontlight systems and

offers designers maximum flexibility

with respect to efficiency and cost.

The LX1992 features a pseudo-

hysteretic pulse frequency modulation

topology and uses an external N-

Channel MOSFET.

Further, the

LX1992 features control circuitry that

is optimized for portable systems (e.g.,

quiescent supply current of 80µA

(typ) and a shutdown current of less

than

1µA).

These

design

enhancements provide for improved

performance

in

battery

operated

systems applications.

The device input voltage range is

from 1.6V to 6.0, allowing for a wide

selection of system battery voltages

and

start-up

operation

is

guaranteed at 1.6V input.

Programming the output current is

readily achieved by using one external

current sense resistor in series with the

LEDs.

In this configuration, LED

current provides a feedback signal to the

FB pin, maintaining constant current

regardless of varying LED forward

capable of achieving output currents in

excess of 150mA, depending on the

MOSFET selected.

The LX1992 has 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 via

an analog reference signal or a direct

PWM generated signal applied to the

ADJ pin and any PWM amplitude is

easily accommodated with a single

external resistor.

The LX1992 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

> 90% Efficiency

80µA 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 or 8-Pin

MLP

APPLICATIONS/BENEFITS

Pagers

Wireless Phones

PDAs

Handheld Computers

General LCD Bias Applications

LED Driver

Digital Camera Displays

PRODUCT H I GHLIGHT

C

1

L

1

1206 Case Size

LX1992

GND

FB

CS

DRV

SHDN

IN

ADJ

SRC

R

SET

15 Ω

V

ON OFF

V

I

R

CS

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

LX1992CLM

LX1992CDU

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

LX1992CDU-TR)