Making Advanced BLDC Motor Control More Accessible
New Tech Tuesdays
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Published April 21, 2026
As much as 50 percent of the world's energy is used in motors.[1] This includes everything from pumps and fans to industrial drives. With such a large energy bill, designers are always on the lookout for more efficient solutions. Many applications demand the use of motors suitable for direct current (DC) power supplies.
Brushed DC motors are arranged so that the energized coil windings are part of the rotating assembly. The coils are connected to the power supply by brushes that both complete the circuit and provide the commutation, which delivers the correct sequencing of the polarity of the coils. As the rotor moves, the brushes make contact in turn, ensuring correct coil polarity and commutation. Little additional control is required, as the motor's rotation provides the sequencing of the coils.
However, the brushes cause friction, reducing the overall efficiency of the motor as energy is lost as heat. The physical contact also causes wear, which lessens the lifespan of the motor and requires additional maintenance.
As designers look for more efficient, lower-complexity motor-drive solutions, new microcontroller units (MCUs) with integrated simultaneous-sampling analog-to-digital converters (ADCs) and advanced pulse-width modulation (PWM) timers are making sensorless field-oriented control (FOC) practical for low-end brushless DC (BLDC) applications. This week’s New Tech Tuesdays explores how these integrated control features bring high-precision motor performance within reach for cost-sensitive consumer and light industrial designs.
Eliminating the Brush
The alternative to conventional motors is BLDC motors. BLDC technology reverses the arrangement of the coils and magnets. The coils are fixed on the outer casing of the motor, and the permanent magnets are attached to the rotor. Unlike a conventional motor, in which the rotation of the motor provides the commutation, an electronic controller is used to detect the rotor's position and to create a rotating magnetic field in the coils that drives the motor.
BLDC motors offer greater efficiency. There is no need for brushes, which both increases the efficiency of the coils and reduces the need for maintenance. As a result, a BLDC motor has a longer expected lifespan than a comparable brushed design, with more electrical energy converted into mechanical power. The lack of direct physical contact also results in a quieter and smoother motor.
The Need for Control
Beyond improving motor performance, using dedicated electronics allows for very accurate control over the speed, torque, and position of the motor. This precision benefits applications ranging from consumer appliances to industrial automation.
Control is essential, so BLDC motor control schemes often rely on methods such as Hall sensors, which, while being effective, add complexity to the design. These sensors can also limit smoothness and precision, reducing efficiency at low speeds. The alternative is to adopt sensorless FOC technology. FOC eliminates the need for position sensors by estimating rotor position from phase current and voltage measurements.
Unlike sensors, which detect the position directly, FOC estimation requires computing power to analyze and interpret real-time measurements of all three motor phase currents. The digital signal controllers and additional external analog components of this approach bring increased cost and design complexity. However, the usefulness of BLDC motors means that a simpler integrated solution would benefit many entry-level consumer and light industrial applications.
The Newest Products for Your Newest Designs®
The Renesas Electronics RA2T1 MCU family is designed to optimize BLDC motor control applications. These MCUs integrate high-speed ADCs with simultaneous sampling to support accurate three-phase current measurement. This simultaneous sampling is a key requirement for sensorless FOC. Additionally, advanced timer units provide complementary PWM outputs with dead-time control, which simplifies inverter drive design.
Built on a 32-bit Arm® Cortex®-M23 core, RA2T1 MCUs offer enough processing performance for real-time motor control while maintaining low power consumption. With integrated motor control peripherals, these devices reduce the need for external components and deliver compact, cost-effective motor drive solutions for fans, pumps, and power tools.
Tuesday’s Takeaway
Sensorless FOC is no longer limited to high-end motor drives. With entry-level MCUs that integrate simultaneous-sampling ADCs and advanced PWM timers, designers can employ precise, efficient BLDC motor control with fewer components and lower complexity. By simplifying development, motor-driven applications in home appliances, power tools, and industrial automation can accelerate time-to-market.
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