New-Tech Europe | March 2017 | Digital Edition

Automotive Special Edition

LED Dimming Engine: An 8-bit MCU-based solution for a Switched-Mode Dimmable LED driver

Mark Pallones, Microchip Technology Inc.

1, the LED dimming engines can be created out of the peripherals available in the microcontroller. Each of these engines has an independent closed channel that can control the switched-mode power converter with minimal to no central processing unit (CPU) intervention. This leaves the CPU free to perform other important tasks such as supervisory functions, communications or added intelligence in the system. LED DIMMING ENGINE In Figure 2, the LED driver, which is based on the Current-Mode Boost converter, is controlled by the LED dimming engine. The engine is mainly composed of core independent peripherals (CIP) such as complementary output generator (COG), digital signal modulator

color and temperature maintenance and remote communications and control, are just some of the advanced capabilities that can make intelligent lighting solutions even more attractive. Although LED drivers offer many advantages over previous lighting solutions, there are also challenges in their implementation. But fear not, by the end of this article you’ll learn how an 8-bit MCU can be used to alleviate design challenges and create high-performance switched- mode LED driving solutions with capabilities beyond that of traditional solutions. An 8-bit microcontroller can be used to independently control up to four LED channels which is something most off-the-shelf LED driver controllers cannot provide. In Figure

Switched-mode dimmable LED drivers are known for their efficiency and precise control of LED current. They can also provide dimming functionality which allows the end user to create fantastic lighting effects while reducing their power consumption.An8-bitmicrocontroller (MCU) implementation can provide the necessary building blocks to create solutions that enable communications, customizations and intelligent control. Additionally, core independent peripheral integration provides significant flexibility versus that of pure analog or ASIC implementation and enables innovation that expands lighting product capabilities and provides product differentiation. Features such as predictive failure and maintenance, energy monitoring,

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