FOC motor control board for embedded drives

MIKROE has introduced a compact embedded motor control board designed to implement field-oriented control for three-phase brushless DC motors in applications such as automotive auxiliaries and industrial actuators. The solution targets developers who need predictable motor behavior, low acoustic noise, and efficient current control within mikroBUS-based systems.

Addressing control complexity in BLDC motor applications
Brushless DC motors are widely used in automotive and industrial equipment because of their efficiency, long service life, and controllability. However, achieving smooth torque delivery and low noise across varying loads requires advanced control methods. Field-Oriented Control (FOC) is commonly adopted to meet these requirements, but it increases system complexity, particularly in compact embedded designs where power electronics, sensing, and firmware must be tightly integrated.

The BLDC FOC 2 Click board was developed to reduce this integration effort by combining power-stage control, sensing, and configuration interfaces into a single add-on module compatible with the mikroBUS™ standard. This approach allows engineers to evaluate FOC-based motor control without designing a dedicated control board from scratch.

Automotive-grade controller at the core
At the center of the board is the A89307 motor controller from Allegro Microsystems, an automotive-qualified device designed specifically for FOC-driven BLDC motors. The controller supports supply voltages from 4.4 V to 30 V and delivers up to 15 A of output current, covering a broad range of low- and medium-power motor applications.

The device supports multiple operating modes, including constant speed, torque, power, and open-loop control. These modes allow the same hardware platform to be adapted to different use cases, such as cooling fans, pumps, or small actuators, by adjusting configuration parameters rather than redesigning hardware.

Managing noise, efficiency, and protection
FOC inherently improves efficiency and torque smoothness by controlling the stator current vector in real time. In this implementation, the controller integrates Allegro’s Soft-On Soft-Off (SOSO) function, which manages startup and shutdown transitions to reduce audible noise and mechanical stress. This is particularly relevant in automotive environments, where acoustic comfort and component longevity are design constraints.

The controller also includes protection features typical of automotive motor drives, such as overcurrent, overvoltage, and thermal safeguards. These mechanisms are intended to maintain stable operation under variable load conditions and fault scenarios, which are common in industrial and vehicle-based systems.

Configuration and system integration
System configuration and control are handled through an I2C interface and onboard EEPROM, enabling parameter storage and runtime adjustment without external programming hardware. The board supports both analog and digital control schemes, allowing it to interface with a wide range of host microcontrollers and control architectures.

Automatic board identification is enabled through the ClickID function, which allows compatible host systems to recognize the board without manual setup. This reduces integration time during evaluation and prototyping phases.

Position within an embedded motor control ecosystem
The BLDC FOC 2 Click board is part of MIKROE’s broader mikroBUS™-enabled ecosystem, which includes a large number of motor control and peripheral expansion boards. Support through open-source mikroSDK libraries allows developers to reuse reference code and adapt it to their own control strategies, accelerating proof-of-concept development and reducing firmware risk.

In practical terms, this positions the board as an evaluation and prototyping platform for engineers working on automotive auxiliary systems, industrial drives, or other embedded applications where compact, efficient BLDC motor control is required without the overhead of a fully custom design.

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