Atmel LED drivers

 June 28, 2011, we talked with Tushar Dhayagude, Marketing Director, Smart Power Business Unit at Atmel about the new LED driver family of products. These devices for lighting control feature system-centric solutions in various applications and are a result of the acquisition of mSilica.

All the part families are intended for managing and controlling multiple LED strings for applications like LED backlight for direct lighting. LED scan rates can go up to 30 kHz, although most applications will use lower frequencies. For short strings in backlights, the controller can increase dynamic range through local dimming.

For smart lighting interfaces, the controllers include DC-DC and AC-DC controller circuitry to adaptively manage the external power supplies. The controllers can sink up to 100 mA and can drive up to 16 parallel strings of 10 LEDs. Interfacing the controller to an MCU brings intelligence and connectivity to interior lighting. These lighting applications can communicate to the smart house DALI or Zigbee interfaces.

In the high power line, the controllers connect to external pass MOSFETs for applications like architectural outdoor lighting with color matching. Light intensity is via peak current control for optimal operation at the operating point. The controller requires an external PWM DC power supply to supply the power and a closed loop feedback with external sensors for color matching. Fault detection results in an interrupt signal to the MCU in approximately 100 ms from internal current detection circuits. The high-power supply needs to have its own protection capabilities for hard shorts or overvoltage.

Future product line extensions will include integrated sensors for intensity and color matching and also will be available in modules and panels. Software for design, sample GUI, and reference designs are available now.