New AI-enhanced MCUs mark major breakthrough

ROHM has developed AI-equipped MCUs (AI MCUs) – ML63Q253x-NNNxx and ML63Q255x-NNNxx – that enable fault prediction and degradation forecasting using sensing data in a wide range of devices, including industrial equipment such as motors. These MCUs are the industry's first to independently execute learning and inference without relying on a network connection.

As the necessity for efficient operation of equipment and machinery continues to grow, early failure detection and improved maintenance efficiency have become key challenges. Equipment manufacturers are seeking solutions that permit real-time monitoring of operational status while avoiding the drawbacks of network latency and security risks. Standard AI processing models, however, generally depend on network connectivity and high-performance CPUs, which can be costly and difficult to install.

In response, the company has developed groundbreaking AI MCUs that allow standalone AI learning and inference directly on the device. These network-independent solutions support early anomaly detection before equipment failure – contributing to a more stable, efficient system operation by lowering maintenance costs and the risk of line stoppages.

The new products adopt a simple three-layer neural network algorithm to implement the company's proprietary on-device AI solution 'Solist-AI'. This enables the MCUs to perform learning and inference independently without requiring cloud or network connectivity.

AI processing models are generally classified into three types: cloud-based, edge, and endpoint AI. Cloud-based AI performs training and inference in the cloud, while edge AI utilises a combination of cloud and on-site systems – such as factory equipment and PLCs – connected via a network. Typical endpoint AI conducts training in the cloud and performs inference on local devices, so a network connection is still required. Furthermore, these models typically perform inference through software, necessitating the use of GPUs or high-performance CPUs.

In contrast, the company's AI MCUs, although categorised as endpoint AI, can independently carry out learning and inference through on-device learning, allowing for flexible adaptation to different installation environments and unit-to-unit variations, even within the same equipment model. Equipped with ROHM's proprietary AI accelerator 'AxlCORE-ODL', these MCUs deliver approximately 1,000 times faster AI processing compared to the company's conventional software-based MCUs (theoretical value at 12MHz operation), allowing real-time detection and numerical output of anomalies that "deviate from the norm". Also, high-speed learning (on-site) at the point of installation is possible, making them excellent for retrofitting into existing equipment.

These AI MCUs feature a 32-bit Arm Cortex-M0+ core, CAN FD controller, three-phase motor control PWM, and dual A/D converters, attaining a low power consumption of approximately 40mW. As such, they are suited for fault prediction and anomaly detection in industrial equipment, residential facilities, and home appliances.

The lineup will comprise 16 products with varying memory sizes, package types, pin counts, and packaging specifications. Mass production of eight models in the TQFP package began sequentially in February 2025. Among these, two models with 256KB of Code Flash memory and taping packaging are available for purchase, together with an MCU evaluation board, through online distributors.

The company has released an AI simulation tool (Solist-AI Sim) on its website that permits users to evaluate the effectiveness of learning and inference before deploying the AI MCU. The data generated by this tool can also serve as training data for the actual AI MCU, supporting pre-implementation validation and improving inference accuracy.