CMU-112 ELECTRONIC BOARD

CMU-112 — accurate monitoring and balancing for 12 cells

The XAP Technology CMU-112 is a cell monitoring and balancing unit designed for automotive and industrial battery architectures. It measures 12 cell voltages, monitors up to eight temperatures and sends data to the BMU over an isolated CAN bus. Its modular design enables integrators to build anything from a 48 V battery pack to a high-voltage architecture of up to 800 V without modifying the CMU hardware.

The CMU-112 combines filtered, oversampled measurement channels with a stated accuracy of ±1 mV. Its passive balancing system sequentially discharges the cells with the highest voltage, targeting a voltage difference below 25 mV between cells. The microcontroller coordinates measurement, fault detection, balancing and communication.

Each unit operates autonomously within the XAP BMS architecture. Automatic identification and dynamic addressing simplify wiring and in-field reconfiguration, while the integrated memory stores the information required for traceability, including the serial number, calibration parameters and firmware identifier.

The stated 3,000 V galvanic separation between the cell domain, logic and CAN bus supports controlled electrical integration. XAP complements this architecture with reverse-polarity protection, electrostatic discharge suppression, overvoltage clamping and open-wire detection.

Applications

The CMU-112 integrates into modular battery management systems for automotive and industrial environments, from 48 V battery packs to high-voltage architectures of up to 800 V.

Key benefits

• Monitoring for 12 cells, from 0 to 5 V per channel, with a stated accuracy of ±1 mV.
• Temperature monitoring through 6 external NTC sensors and 2 internal sensors.
• Passive balancing through an approximately 4.7 Ω / 3 W resistor per cell.
• Communication over an isolated CAN bus with automatic EEPROM identification.
• Modular architecture for systems from 48 V to 800 V without modifying the CMU hardware.

Technical specifications and integration

The CMU-112 integrates as a cell monitoring unit within the XAP BMS architecture. It receives a 12 to 17 V DC supply from the BMU and communicates over an isolated CAN bus. EEPROM identification and dynamic addressing allow multiple units to be organised within a modular architecture.

Integration

The integrator connects the 12 voltage channels, up to 6 external NTC sensors, the BMU power supply and the CAN bus in accordance with the system documentation. The source does not provide a pinout or connector reference, so XAP must confirm the wiring, battery-pack protection, CAN termination and BMU compatibility before final installation.

Documentation

View the official CMU-112 datasheet.