New Industry Products

Maxim Introduces LED Driver Controller for Projection and Lighting Applications

December 10, 2006 by Jeff Shepard

Maxim Integrated Products introduced the MAX16818 high-efficiency LED-driver controller for projection and lighting applications that utilize the next-generation of high-power light-emitting diodes (LEDs). The MAX16818 is the first LED-driver controller that enables Maxim's patent-pending technology for rapid LED-current transients of up to 20Aµs and 30kHz dimming frequency.

The MAX16818 pulse-width-modulation (PWM) controller provides high-output-current capability in a compact, lead-free package with a minimum number of external components. Average current-mode control, synchronous gate-drive circuitry, and a wide switching-frequency range make this device well-suited for the energy-efficient driving of high-power LEDs in light sources for business, portable, and pocket projectors; home theater systems; rear-projection TVs; and automotive and industrial lighting fixtures.

The MAX16818 is suitable for use in synchronous and nonsynchronous step-down (buck) topologies, as well as in boost, buck-boost, SEPIC, and Cuk LED drivers. This device employs average-current-mode control, which optimizes the charge and on-resistance characteristics of MOSFETs, thus minimizing the need for external heat sinking, even when delivering LED current up to 30A. Its flexibility and small footprint make 5 to 200W driver designs possible with the industry's highest efficiency (up to 94%). True differential sensing enables accurate control of the LED current. A wide dimming range is easily implemented to accommodate an external PWM signal. An internal regulator enables operation over a wide input-voltage range of 4.75 to 5.5V, 7 to 28V, or higher with a simple external biasing device. The wide switching-frequency range available (up to 1.5MHz) allows for the use of small inductors and capacitors.

The MAX16818 features a clock output with 180° phase delay to control a second out-of-phase LED driver, which reduces the required size of the input and output filter capacitors and minimizes ripple currents. This device also offers programmable hiccup-mode overcurrent, overvoltage, and overtemperature protection.

The MAX16818ETE+ is rated for the extended temperature range (-40 to +85°C) and the MAX16818ATE+ is rated for the automotive temperature range (-40 to +125°C). Each LED driver controller is available in a tiny, lead-free, 5mm x 5mm x 0.8mm, 28-pin TQFN package with exposed pad. Prices start at $1.82 for MAX16818ETE+ and $1.59 for MAX16818ATE+ (1000-up, FOB USA).