The evaluation board for automotive applications enhances motor management with microcontroller unit technology and speed control through algorithms.
BLDC motor control is increasingly vital in the automotive industry, enhancing performance, efficiency, and environmental sustainability. These motors are preferred for reliability, longevity, and superior operational characteristics, such as higher torque and better speed control than traditional brushed motors. Employing low-voltage BLDC motors in automotive applications offers significant advantages, including reduced energy consumption, lower emissions, and decreased maintenance costs. As the industry shifts toward more sustainable and innovative vehicle designs, the integration of BLDC motor technology becomes essential for meeting modern automotive standards and consumer expectations. The AEK-MOT-3P99081 evaluation board from STMicroelectronics is equipped with the SPC560P Pictus 32-bit MCU and the L9908 gate driver, enabling the management of six N-channel FETs for brushless motors in automotive applications.
The design supports independent encoder inputs and Hall sensors, providing precise motor speed detection and control. The drive system uses a field-oriented control (FOC) algorithm, ensuring compact size, quiet operation, and high precision. It is controlled through a standard CAN command set from any existing domain or zone controller, simplifying the management of control loop bandwidth and resource demands.
As part of the AutoDevKit ecosystem, the board operates as a standalone motor drive controllable via CAN by a host microcontroller. In this configuration, the microcontroller acts as the communication master, with the board and its connected BLDC motor operating as the enslaved person. The board’s dedicated CAN communication protocol allows for real-time data exchange between the master and slave boards. This setup enables commands to start or stop the motor, modify the motor’s target speed, reverse its rotation direction, and relay error notifications during faults.
The evaluation board is a robust assembly designed specifically for automotive applications. At its core, the Microcontroller Unit (MCU), the SPC560P50L5, is a 32-bit power architecture MCU suited for automotive chassis and safety applications. Programming can be done via the integrated programmer/debugger using the FTDI module FT2232HL or an external adapter connected to the JTAG connector.
Furthermore, the board includes a gate driver and an automotive three-phase motor gate driver equipped with all the necessary features for BLDC motor control. This comprises three differential high-accuracy current monitors for monitoring ground-referred currents. Safety is paramount in the board’s power supply unit, which guards against battery polarity inversion and ensures reliable power generation. It comprises a DC-DC converter generating a 10.9 V reference voltage from the input bus voltage and two voltage regulators that provide 5 V to power both the microcontroller and the gate driver.
Moreover, the board features a high-speed CAN flexible data rate transceiver, the L9616, which enhances CAN communication with the master board, facilitating seamless integration and control within automotive systems.
STMicroelectronics has tested this reference design. It comes with a bill of materials (BOM), schematics, assembly drawing, printed circuit board (PCB) layout, and more. The company’s website has additional data about the reference design. To read more about this reference design, click here.
