STMicroelectronics – Digital controller for LED lighting enables precise PWM dimming


STMicroelectronics’ STLUX285A is a highly integrated system controller for configurable lighting fixtures which provides fast and precise PWM dimming of LED light sources.

A member of the STLUXTM family of controllers for lighting and power-conversion applications, it enables fully configurable lighting to deliver the right amount of light where and when it is needed, supporting the detection and dimming capabilities required to save energy in outdoor lighting installations.

STLUX controllers offer excellent efficiency at full load and in idle mode. LED brightness can be controlled down to very low current levels with great precision, because the device is digitally calibrated in production. An integrated Digital Addressable Lighting Interface (DALI) enables remote control and is interoperable with sensors used in smart lighting.


At the heart of the STLUX285A are its four State Machine Event Driven (SMED)-controlled PWM generators, which provide full control of any power-conversion stage. The SMED units have a maximum resolution of 1.3ns and a 10ns event detection and reaction time.

The STLUX285A also includes an STM8® microcontroller core based on the Harvard architecture, a three-stage pipeline, and operates at a maximum clock speed of 16MHz.


  • Four analogue comparators
  • 10-bit, 8-channel ADC
  • 32kbytes of Flash
  • 1kbyte of EEPROM
  • 2kbytes of RAM
  • 96MHz PLL clock
  • UART and I2C interfaces


  • LED lighting in high-end, highly-configurable applications
  • Smart lighting solutions


The evaluation board provides a platform for designing a 150W HID digital ballast. The board can drive sodium or metal halide HID lamps. It is comprised of two stages: the power factor corrector, and the inverter. The STLUX digital controller drives both stages.

Orderable Part Number: STEVAL-ILH007V1