1.5MHz, 30A High-Efficiency LED Driver with Rapid LED Current Pulsing

The MAX16818 pulse-width modulation (PWM) LED driver controller provides high-output-current capability in a compact package with a minimum number of external components. 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. The MAX16818 is the first LED driver controller that enables Maxim's technology for fast LED current transients of up to 20A/µs and 30kHz dimming frequency.

This device utilizes average-current-mode control that enables optimal use of MOSFETs with optimal charge and on-resistance characteristics. This results in the minimized need for external heatsinking even when delivering up to 30A of LED current. 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: 4.75V to 5.5V or 7V to 28V and above with a simple external biasing device. The wide switching frequency range, 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 to reduce input and output filter capacitors size or to minimize ripple currents. The MAX16818 offers programmable hiccup, overvoltage, and overtemperature protection.

The MAX16818ETE+ is rated for the extended temperature range (-40°C to +85°C) and the MAX16818ATE+ is rated for the automotive temperature range (-40°C to +125°C). This LED driver controller is available in a lead-free, 0.8mm high, 5mm x 5mm 28-pin TQFN package with an exposed pad.

Applications

* Front Projectors/Rear Projection TVs * LCD TVs and Display Backlight * Portable and Pocket Projectors

* Flexible Architecture Supports a Range of LED LIghting Applications with Minimal Component Count

* Up to 30A Output Current

* 4.75V to 5.5V or 7V to 28V Input Voltage Range

* Average-Current-Mode Control

* True-Differential Remote-Sense Input

* Frequency Management Reduces EMI and Interference with Other System Clocks

* Programmable Switching Frequency or External Synchronization from 125kHz to 1.5MHz

* Clock Output for 180° Out-of-Phase Operation

* Integrated Protection Features and Thermally Enhanced Package Improve System Reliability

* Output Overvoltage and Hiccup-Mode Overcurrent Protection

* Thermal Shutdown

* Thermally Enhanced 28-Pin TQFN Package