RangeMAX™
LXM1614E-14-11
®
DUAL DIMMING, EXTENDED TEMPERATURE CCFL INVERTER MODULE
TM
PRELIMINARY DATASHEET
0.5 - VBST
4.5VDC
HOW THE RANGEMAX WORKS
High Voltage
Transformer
Gain &
Summing
Transformer
Driver
VOUT1
VBRT
0.5 -
4.5VDC
Comparator
Ramp +
-
VSENSE
ISENSE
VSYNC
Temperature
I/V
Ramp Gen.
Sense
& PLL
VOUT2
Figure 1 – RangeMAX Simplified Block Diagram
HIGHLIGHTS
• Integrated dual brightness control circuit includes a DC
voltage to pulse width converter that minimizes system
design work and system noise susceptibility. This provides
a familiar and convenient interface while reducing the
potential for externally induced noise, which can cause
lamp flicker.
• RangeMAX inverter modules are designed to operate with
the burst frequency synchronized to the video frame rate.
This provides operation with no visible display disturbances
caused by beat frequencies between the lamps and video
frame rates. In this synchronous mode, the inverter burst
rate operates at twice the video refresh rate, well beyond
standard 50/60Hz video refresh rates where the eye can
perceive pulsing light. The frequency at the VSYNC input
will affect the minimum dimming level. Generally, the
potential dimming (or brightness) range is inversely
proportional to the VSYNC frequency.
• In applications with no access to a vertical sync, an
onboard oscillator operates the inverter burst rate at
about 170Hz. In this non-synchronous mode, minor
display disturbances can be found under certain video
conditions. This performance may be acceptable for
many applications, but synchronization must be used
when no disturbance can be tolerated.
• Separate feedback loops for lamp current and open
circuit voltage regulation insure reliable strike under all
operating conditions, automatic over-voltage prevention
with broken or failed lamps, and accurate lamp current
regulation.
• A single input will accommodate negative and positive
vertical sync pulses at any pulse width.
Copyright © 2004
Rev. 0.2,2005-01-14
Microsemi
Microsemi Integrated Products
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
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