November 12, 2013 – Silicon Labs (NASDAQ: SLAB, Country Manager In-gyu Kim), a global leader in high-performance analog-intensive mixed-signal ICs, announced today a BLDC motor control reference design that provides ready-to-use hardware and software for sensorless BLDC (brushless DC) applications using Silicon Labs' C8051F85x/6x microcontrollers (MCUs). Silicon Labs’ new reference design provides a comprehensive system-grade solution that can accelerate embedded development in a wide range of motor control applications, including remote-controlled helicopters, motor-driven toy cars, electronic speed controllers, PCs, and electric fans, as well as power tools such as cutters, razors, lawnmowers, nail guns, and staplers, and small appliances such as blenders, grinders, toothbrushes, and vacuum cleaners.

Embedded system designs are becoming increasingly complex, and development schedules are becoming tighter. Consequently, shortening development time is a key consideration when selecting MCUs for motor control applications. The C8051F85x/6x MCU-based motor control reference design makes the work easier for developers by providing cost-effective hardware and production-quality firmware for rapid evaluation and development in cost-sensitive BLDC applications. In addition, the motor control GUI (graphical user interface) provides developers with greater flexibility and ease of use when controlling and understanding BLDC motor operation, and the use of production-grade motor control source code helps to further shorten the design process.

The sensorless BLDC motor control reference design uses a C8051F850 MCU to control a BLDC outrunner motor (typically found in toy helicopters) mounted on a motor board. The powertrain board includes a gate driver, power MOSFETs, current-sensing resistors, as well as a resistor divider that attenuates the motor phase voltage, which can be measured by the C8051F85x/6x MCU. The MCU board includes buttons for start/stop, changing the motor direction, and resetting the MCU, in addition to the C8051F85x/6x MCU. The PWM output of the MCU drives the gate drive on the powertrain board. The MCU board also includes an operational amplifier (op-amp) that amplifies the current-sensing voltage, allowing the MCU to measure it.

The C8051F85x/6x product family is highly suitable for BLDC applications because it offers industry-leading analog performance, a small footprint, and other features optimized for motor control design. The cost-effective, high-performance 8051-based MCU rotates a 6-pole motor in a reference design kit at speeds up to 50,000 rpm. The C8051F85x/6x MCU family eliminates the need for external components such as crystal oscillators, voltage references, level shifters, temperature sensors, and other discrete devices, enabling developers to reduce overall system costs.

Silicon Labs' sensorless BLDC reference design is designed to provide developers with a productive and comprehensive “out-of-the-box” experience, offering everything related to rotary motor products within 5 minutes. The reference design includes the following hardware and software tools:

• C8051F850 MCU control board for controlling motors and associated peripherals
• Powertrain board equipped with gate driver and power MOSFET
• Turnigy 450 Series 3800 kV BLDC outrunner motor attached to the motor mount board
• Software tools including a CD with application notes, production-ready motor control firmware source code, and a motor control GUI
• Free Keil® PK51 development software with no license restrictions (worth approximately $2,500)
• Power supply and USB cable

Diwakar Vishakhadatta, Vice President and General Manager of 8-bit MCU Products at Silicon Labs, said, “Rapid application development, reduced system costs, and rapid time-to-market are the most important factors for embedded developers designing cost-sensitive motor controls. We have developed a sensorless BLDC motor control reference design to make developers’ work easier and generate higher productivity, and significant benefits can be enjoyed when designing BLDC systems based on the entry-level C8051F85x/6x MCUs.”