Motor control integrated circuits (ICs) and motor drives are essential elements for implementing smart manufacturing within the framework of Industry 4.0. A common requirement in modern industrial applications is high-efficiency motor solutions. About 50% of global energy consumption is due to electric motors, and therefore, even a moderate improvement in efficiency can provide meaningful economic benefits, helping reduce the carbon footprint.
International efficiency standards for industrial motors, such as IE3 (Premium) and IE4 (Super Premium), have been introduced to reduce energy use. As of July 2023, European regulations mandate that three-phase induction motors between 75 kW and 200 kW adhere to the IE4 efficiency standard.
In addition to being more efficient, modern industrial motor solutions must be smart and connected. “Smart devices” are equipped with sophisticated capabilities. They can identify irregularities such as excessive heat or voltage surges and respond automatically. The introduction of AI technologies, such as machine learning, brings this function to the next level, allowing predictive maintenance and reducing factory downtime.
Connection is another key requirement for motor solutions deployed in the Industry 4.0 sector. This feature allows the devices to exchange data in real time, supporting predictive maintenance, energy efficiency improvements, and remote control. Using the industrial internet of things, electric motors can send operational data to cloud systems. This helps reduce downtime and allows for continuous improvement of production processes. Moreover, technicians can access performance data remotely, decreasing the need for on-site inspections and allowing faster troubleshooting.
Motor driver architecture
Motor driver electronics is the power interface between digital control systems and electromechanical loads. This architecture is based on three components: control logic, gate drivers, and power stages.
Control logic typically resides within microcontrollers (MCUs), digital-signal processors, or dedicated motor control ICs, which are engineered to perform real-time control loops. Subsequently, gate drivers transform these logic-level signals into switching commands, which are then employed to regulate power transistors, encompassing MOSFETs and IGBTs. The power stage, frequently implemented via inverter or H-bridge configurations, supplies the desired current to the motor windings.
Furthermore, in Industry 4.0 contexts, motor drivers incorporate supplementary functionalities, encompassing fault monitoring, thermal sensing, communication interfaces, and energy management capabilities. Motor driver ICs also feature integrated protective measures, such as overcurrent, overvoltage, and thermal shutdown mechanisms. These protections improve system reliability and simplify the design process.
Microchip Technology Inc. recently introduced a lineup of 12 600-V gate drivers. These high-voltage drivers are designed to deliver output currents between 600 mA and 4.5 A. They are also available in a range of configurations, including half-bridge, three-phase driver, and high-side/low-side options.
These gate drivers facilitate rapid switching, thereby promoting efficient performance, and are particularly appropriate for industrial motor control applications. In addition, the logic inputs are compatible with standard TTL and CMOS levels, extending down to 3.3 V, which streamlines integration with conventional MCUs. The safe operation of the output power MOSFETs is ensured by Schmitt triggers on the inputs and an internal deadtime preset.
The MCP8062136, for instance, is a three-phase half-bridge with three high-side drivers operating in bootstrap operation up to 600 V and can provide a 200-mA source and 350-mA sink output current. The gate drivers also include several protection features, including shoot-through protection logic, undervoltage lockout for VCC, and overcurrent protection.
To drive motor-controlled industrial applications such as sensorless three-phase fans and pumps up to 40 W, Melexis has introduced the MLX81339 motor control IC. The device is also suitable for driving brushless DC (BLDC) and bipolar stepper motor control for accurate positioning in applications such as automated valves, flaps, and small robotic motors.
The MLX81339 supports several types of communication interfaces with a host MCU, including the legacy PWM/FG, as well as the I2C, UART, and SPI interfaces. The motor control IC offers several protection and diagnostics features, including undervoltage, overvoltage, overcurrent, and overtemperature detection and protection, and integrates a programmable flash memory that can be used for application customization and IC configuration.
Connectivity in smart motor control
In Industry 4.0 applications, motor drivers often adopt communication protocols, such as EtherCAT, Profinet, and Ethernet/IP, to exchange real-time data with other drives, sensors, or systems supervising the industrial network. Typical data that can be exchanged includes torque, speed, temperature, and vibration. When processed at the edge or remotely on the cloud, this data allows predictive-maintenance models to provide valuable insights into motor operation, helping to detect potential faults before they occur.
Drive units mounted directly on motors or industrial machines are becoming very common. These devices, which include embedded controllers and communication interfaces, reduce the wiring complexity and allow machines to be reconfigured quickly for different production requirements.
For example, the RA8T2 MCU from Renesas Electronics Corp. is optimized for industrial motor control. Based on a 1-GHz Arm Cortex-M85 processor (with an optional 250-MHz Arm Cortex-M33 processor available in the dual-core version), the RA8T2 is designed for industrial motor control applications that require real-time performance and a high-speed communication interface.
These devices (Figure 2) integrate a 14-channel PWM timer for motor control, different types of memories (including a low-latency and high-speed TCM memory), and analog functions in a single chip. They also provide a dual-channel Gigabit Ethernet MAC with DMA and an optional EtherCAT slave controller that supports synchronous networks in industrial fields.
Wide-bandgap semiconductors
Wide-bandgap materials, such as silicon carbide (SiC) and gallium nitride (GaN), provide higher breakdown voltages, faster switching speeds, and lower on-resistance per unit area than silicon IGBTs and MOSFETs. From a designer’s perspective, this means that lower switching losses, improved thermal management, and higher operating frequencies can be achieved. These characteristics also lead to higher efficiency across the load range and a reduced footprint due to a reduced size of the passive components.
SiC is usually preferred in high-voltage and high-current applications above 600 V, such as high-power industrial drives and inverters. GaN, meanwhile, operates well in the 100- to 650-V range, with switching frequencies up to about 1 MHz. It is well-suited for mid-power motor drives in appliances, HVAC, pumps, small robots, and light industrial equipment.
Through a partnership, Qorvo Inc. and Cambridge GaN Devices (CGD) have developed the 400-W PAC5556AEVK2 and the 800-W PAC5556AEVK3 evaluation kits, suitable for developing motor control solutions in applications such as industrial fans, pumps, compressors, and white goods. The kits combine Qorvo’s PAC5556A mixed-signal system-on-chip with CGD’s ICeGaN HEMTs. The PAC5556A is a programmable 32-bit MCU that integrates a 600-V DC/DC buck controller and 600-V gate drivers.
The PAC5556AEVK2 evaluation kit features CGD’s 240-mΩ ICeGaN power devices, achieving up to 400-W peak performance without requiring a heat sink. The PAC5556AEVK3 integrates CGD’s 55-mΩ ICeGaN switches and provides a peak output power of 800 W, requiring minimal airflow cooling. The usage of GaN transistors improves the overall efficiency due to reduced power loss, reduces heat dissipation, and allows for smaller and more reliable motor control solutions.
Efficient Power Conversion (EPC), a company focused on e-mode GaN solutions, introduced the EPC91202 evaluation board for motor drive applications. It integrates a three-phase BLDC motor drive inverter built on the EPC2361 100-V eGaN FET and can provide an output current up to 70 A peak (50 ARMS), with a switching frequency up to 150 kHz.
The EPC91202 is designed to handle sensorless and encoder-based motor control, boasting a low-voltage change rate, specifically a dV/dt rate of under 10 V/ns. This low voltage change rate reduces electromagnetic interference and acoustic noise. This board is well-suited for developing motor drive applications in various sectors. These include industrial automation, e-mobility, robotics, drones, and battery-powered devices.
AI and ML integration
Integrating AI/ML in motor control systems offers a valuable solution to investigate the behavior of motors during normal operation, helping to prevent anomalies or possible faults in advance. An example of a hardware and software integrated solution is the STSPIN32G4-ACT reference design and the FP-IND-MCAI1 STM32Cube function pack from STMicroelectronics.
The STSPIN32G4 is an advanced system-in-package that combines an STM32G431 MCU (based on an Arm Cortex-M4 core with CORDIC mathematical accelerator) with a three-phase gate driver. This architecture is specifically designed for controlling BLDC/permanent-magnet synchronous motors and provides the computing power needed to handle field-oriented control (FOC) algorithms, as well as local data analysis tasks (edge AI).
The FP-IND-MCAI1 software provides an implementation example for condition monitoring and predictive maintenance. This package collects data from internal sensors (current and voltage) and from external sensors (vibration and temperature), using it to feed pre-trained ML models.
Using ST’s NanoEdge AI Studio tool, optimized libraries can be generated that run directly on the chip, enabling the drive to “learn” the motor’s normal behavior and detect anomalies (such as mechanical imbalances or bearing failures) in real time.
Software tools
Several vendors offer software toolchains that cover the full development workflow from motor parameter identification through algorithm configuration, real-time debugging, and production code generation.
Infineon Technologies AG recently expanded its ModusToolbox Motor Suite to include a hardware-abstracted motor control core library covering advanced algorithms such as FOC and trapezoidal control, multiple startup methods including rotor alignment and six-pulse injection for initial position detection, and SVPWM modulation schemes. The integrated graphical user interface (GUI) provides a configurator and testbench that auto-detects connected evaluation boards; a digital oscilloscope monitoring up to eight firmware variables simultaneously; a motor profiler for automated extraction of resistance, inductance, and inertia parameters; and a PID tuner for closed-loop optimization.
Power Integrations released its MotorXpert v3.0 last year, a suite developed for its BridgeSwitch motor driver ICs (Figure 3). It adds shuntless and sensorless FOC support, a two-phase modulation scheme that cuts inverter switching losses by 33% in high-temperature environments, and a five-fold improvement to its waveform visualization tool. The codebase is written in MISRA-C and is MCU-agnostic, covering applications from 30 W to 750 W.
Other development tools available from leading semiconductor manufacturers include ST’s STM32 Motor Control SDK (X-CUBE-MCSDK) and Texas Instruments Inc.’s MotorControl SDK.
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