Microsemi

Linfinity Microelectronics Division

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

Page 4

Copyright

© 2000

Rev. 0.5e, 2000-12-06

LXM1612-05-xx

5V Highly-Integrated, Digital Dimming CCFL Inverter Module

A

M I CROS E M I

COM P A N Y














Burst Mode Operation

  – 50% Burst Duty Cycle

  – 2% Burst Duty Cycle

Rather than using the traditional dimming technique of varying

lamp current magnitude to adjust light output, RangeMAX

inverters use a fixed lamp current value with a duty cycle control

method.

The lamp current burst width can be modulated from 100%

(continuous lamp current) down to a 2% duty cycle, allowing the

lamp to be dimmed to less than 1% of its full brightness.

As can be seen in Trace 4 of Figure 3 photo at right, careful

design consideration was given to controlling lamp start voltage

to softly start current flow. This eliminates current overshoot that

can result in premature cathode wear and reduce lamp life.

  – 2% Burst Duty Cycle (Expanded Time Base)

Ram p Gen

Transform er

Driver

0.25 -

2.5V

DC

+

-

V

LO

V

HI

Comparator

Ramp

V

BRIT E

V

SYN C

High V oltage

Transform er

I

SENSE

V

SENSE

  – RangeMAX Block Diagram