Because the design of brushless DC (BLDC) motors has the characteristics of higher overall efficiency and lower vibration and noise of electrical appliances, the market demand is increasing day by day. This paper will introduce the BLDC motor control reference design of Silicon Labs, so that you can complete the BLDC motor design in a short time.
Five-minute starting BLDC motor control design
A BLDC motor is a DC motor without a brush or commutator. It is a structurally permanent magnet synchronous motor, using power electronic technology (frequency converter) to input an AC signal into the motor. Compared with traditional brush DC motors, BLDC motors are safer and more reliable.
At present, many new energy-saving washing machines on the market use BLDC variable frequency motors. The efficiency is as high as 80%, 40% higher than common motors. BLDC variable frequency motors might be overkill on energy conservation compared to common motors, with obvious noise reduction, which can reduce noise by 15%.
For BLDC variable frequency motors, from the recent experimental tests in many industries, it can be found that BLDC variable frequency motors are superior to the existing motor solutions from energy efficiency, vibration, noise, etc. From fixed frequency to variable frequency, and to the BLDC variable frequency motor which is very popular nowadays, the pace of innovation in motor development has never stopped.
In order to help the industry accelerate the development of a more complete BLDC solution, Silicon Labs has built a set of BLDC motor control reference designs based on its highly integrated, small-sized, and low-powered 8-bit microcontroller (MCU) product. Here's how the reference design can help you quickly seize the BLDC market.
The BLDC motor control reference design based on the 8051F850 series 8-bit MCU from Silicon Labs is a ready-to-use motor control solution, with product-quality hardware and software, which can be quickly evaluated and deployed in the cost sensitivity applications. The reference design provides a complete system-level solution for inductorless BLDC motors and is a tool for developers to evaluate and adopt low-cost BLDC motor control solutions using C8051F85x and C8051F86x product lines.
The BLDC motor control development kits from Silicon Labs contain an MCU development board built-in pre-programmed motor control firmware MCRD-MCU-C8051F850, an MCRD-PWR-NLV-F85X power transmission development board, Turnigy 450 Series 3,800kV Brushless Outrunner Helicopter BLDC motor, motor installation development board, 8-bit MCU kit CD and 12V, 5A common output power adapter, which provide a complete and ready-to-use development kit.
The C8051F85x/6x series is an ideal MCU for BLDC motor control reference design, including a 12-bit analog-digital converter, a precise internal reference voltage, two analog comparators with programmable hysteresis and response time, and three independent configurable enhanced resolution PWM channels with built-in hardware turnoff ability.
The reference design provides the motor control source code, which helps customers speed up the design. In addition, the motor control graphical user interface (Silicon Labs Spinner) allows real-time control and monitoring of the motors, and provides user flexibility and ease of use in controlling and understanding the operation of BLDC motors. The strong value of the inductorless BLDC motor control reference design lies in providing a complete support environment for tools, development kits, software libraries, and accessories. The reference design contains all the elements needed to start the motor in less than five minutes.
The 8051F850 suite supports three-phase BLDC motors that meet the following specifications, including Back Electromotive Force (BEMF), maximum working voltage of 10V to 24V DC, 24 kHz PWM frequency, and maximum average current of 10A. For two-pole BLDC motors, the maximum speed does not exceed 200,000 rpm. When the average current exceeds 10A, the overcurrent detection function will stop the motor. When the motor stalls or encounters an extreme load, the stall detection function will stop the motor and the tachometer frequency generator (FG) will output the signal.
The kit is designed to demonstrate the functions of C8051F850 used to operate BLDC motors. The unique functions provided by the MCU for BLDC motor operation include PWM synchronous blanking comparator, which can be used for BEMF zero-cross detection, and automatic PWM duty cycle reduction to limit the motor current during start-up, which can increase the maximum speed of some motors in Hyperdrive mode.
Silicon Labs also offers UDP C8051F850 MCU cards to provide a platform for development and demonstration of microcontrollers, short-range wireless devices and software tools, including the integrated development environment (IDE) from Silicon Labs for customers through development and a demonstration platform for customers through a unified development platform (UDP). MCU cards can be used independently or with a UDP mainboard to quicken the product development pace.
See related product
