High-Voltage, 350mA LED Driver with Analog and PWM Dimming Control Is Ideal for Automotive and General Lighting Applications
SUNNYVALE, CA—August 23, 2006—Maxim Integrated Products (NASDAQ: MXIM) introduces the MAX16804, a 350mA, high-brightness LED driver. The MAX16804 features a high-voltage (40V) PWM pin that allows a wide dimming range. A wide operating input-voltage range of 5.5V to 40V helps protect against large transients such as load-dump and cold cranking. Among others, these features make the MAX16804 is ideal for automotive, LED industrial, and architectural lighting applications.
An on-board 200Hz ramp generator allows analog or PWM control for PWM or theatre-dimming effect, thus eliminating the need for the microcontroller's PWM signal. The high-voltage (40V-rated) DIM pin can also sync with an external PWM signal up to 2kHz. Fast turn-on/off times ensure a wide dimming range, while the wave-shaping circuitry minimizes EMI.
A fixed, 5V-output regulator delivers up to 2mA of load current for low-power applications throughout the 5.5V 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.
The MAX16804 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, typ) and current-sense reference minimize power dissipation in the system. They can drive multiple LEDs in series up to 39V.
The need for only two small ceramic capacitors and a small sense resistor results in minimal board size and driver cost. The MAX16804 features thermal and short-circuit protection and is rated for operation over the automotive temperature range (-40°C to +125°C). It is available in a thermally enhanced, surface-mount, 5mm x 5mm, 20-pin TQFN lead-free package rated at 2.67W power dissipation (MAX16804). Pricing starts at $1.31 (1000-up, FOB USA).
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