High-Voltage, 350mA, High-Brightness LED Driver with PWM Dimming and 5V Regulator for Automotive, Display, and Lighting Applications
SUNNYVALE, CA-May 4, 2006-Maxim Integrated
Products (NASDAQ: MXIM) introduces the MAX16803,
an adjustable constant current source that
provides up to 350mA of current to one or more
strings of high-brightness LEDs (HB LEDs). A wide
operating input-voltage range of 6.5V to 40V
helps protect against large transients such as
load-dump and cold cranking. Its high-voltage
(40V) PWM pin allows a wide dimming range. The
MAX16803 is ideal for automotive lighting, LED
display backlight, industrial and architectural
lighting applications.
The MAX16803 regulator combines a low-voltage
(204mV) current-sense reference with differential
LED current sensing to provide load accuracy of
±3.5%. This current accuracy allows consistent
brightness for all light assemblies. The device's
low-dropout pass element (0.5V typical) and
current-sense reference minimizes power
dissipation in the system. Multiple MAX16803 LED
driver ICs can be paralleled to deliver current
greater than 350mA to a single high-power LED.
Brightness can be adjusted by using output PWM
dimming in which the dedicated dimming input
(DIM) or VIN is pulsed. Wave-shaped circuitry
generates soft rise and fall LED current edges of
equal duration, and reduces EMI during short
turn-on and turn-off transitions.
A fixed, 5V output regulator delivers up to 4mA
of load current for low-power applications
throughout the 6.5V to 40V input-voltage range.
For greater design flexibility, the regulator can
also power a microcontroller or other external
components. The regulator stays on even when DIM
is pulled low. Two small ceramic capacitors and a
small sense resistor result in a minimal board
size and minimize total driver cost.
The MAX16803 is rated for operation over the
automotive temperature range (-40°C
to +125°C). It features thermal and
short-circuit protection. The device is available
in a thermally enhanced, surface-mount, 5mm x
5mm, 16-pin TQFN package rated at 2.67W power
dissipation. It is also available in a lead-free
package. Prices start at $0.99 (1000-up, FOB USA).
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