Editor's note: Maxim Integrated Products has introduced the MAX16804, a 350mA, high-brightness LED driver. The MAX16804 features a high-voltage (40V) PWM pin for a wide range of brightness adjustments. The wide input voltage range of 5.5V to 40V helps protect against large transients such as load shedding and cold start. These features make the MAX16804 ideal for automotive, LED industrial, and architectural lighting applications. The on-chip 200Hz ramp generator allows for PWM or theater illumination with analog or PWM control, so no microcontroller is required to generate the PWM signal. High voltage (40V rating) The DIM pin can also be synchronized to an external PWM signal up to 2kHz. Fast turn-on/turn-off times ensure a wide range of brightness control, while waveform shaping circuitry minimizes EMI. A fixed 5V regulated output is provided to deliver up to 2mA of load current for low power applications over the entire 5.5V to 40V input voltage range. To make the design more flexible, the regulator can also power microcontrollers or Other external components. The regulator remains active even during DIM pull-down. The MAX16804 regulator combines a low-voltage (204mV) current sense reference with differential LED current sensing to provide ±3.5% load accuracy. This current accuracy allows the brightness of all groups of lamps to be uniform. The device's low dropout regulator (0.5V, typ) and low voltage current sense reference maximizes power loss in the system. They can drive multiple series LEDs up to 39V. The circuit requires only two small ceramic capacitors and a small sense resistor to minimize board size and drive cost. The MAX16804 provides short-circuit and thermal protection and is rated for operation over the automotive temperature range (-40°C to +125°C). The device is available in a thermally enhanced, surface mount, 5mm x 5mm, 20-pin TQFN lead-free package with a power dissipation rating of 2.67W (MAX16804). The device starts at $1.31 (1000 sheets, FOB USA).
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