Date: 5th Jun 2011
White LED drivers for driving up to six
high current WLEDs for signage lighting
Micrel Inc., has unveiled a pair of new linear WLED drivers
aimed at further expanding its portfolio of lighting products.
The MIC4811/MIC4812 are six channel, constant-current sink
LED drivers targeting billboard, marquee, instrument and
other large, general-purpose LED displays.
"The MIC4811/MIC4812 LED channels can operate with
an output voltage on the LED pins as low as 0.19V which
enables more power-efficient designs," noted Doyle
Slack, senior marketing director for Analog. "With
its Dynamic Average Matching architecture, both the MIC4811
and the MIC4812 achieve industry-leading LED channel matching
of 1 percent across the entire dimming range."
The MIC4811/MIC4812 are high efficiency linear White LED
(WLED) drivers designed to drive up to six high current
WLEDs for signage lighting. The MIC4811/MIC4812 provide
the highest possible efficiency at low source voltages as
this architecture has no switching losses present in traditional
charge pumps or inductive boost circuits. These linear drivers
maintain constant current for up to six WLEDs and feature
a typical dropout of 100mV at 50mA (MIC4811) and 190mV at
100mA (MIC4812).
The MIC4811/MIC4812 feature Dynamic Average Matching(DAM)
which is specifically designed to provide optimum matching
across all WLEDs. The high accuracy (±1% typical)
current regulated WLED channels ensure uniform display illumination
under all conditions. The brightness is controlled through
an Ultra Fast PWM interface operating down to less than
1 percent duty cycle. The MIC4811/MIC4812 are available
in an 10-pin MSOP package and a 10-pin MSOP exposed pad
package respectively with a junction temperature range of
-40 ° C to +125 ° C.
The MIC4811/MIC4812 are currently available in volume quantities
with pricing starting at $0.65 and $0.68 respectively for
1Ku quantities. Samples can be ordered on line at: www.micrel.com/ProductList.do.
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