Miniature automotive infrared thermometer IC

The MLX90637 is an advanced Surface Mount Device (SMD) non-contact infrared (IR) temperature sensor specifically engineered for critical temperature monitoring in Electric Vehicle (EV) systems, including inverters, motors, and HVAC.

It provides the high-speed and accuracy, offering substantial advantages over traditional NTC thermistors. This sensor utilizes non-contact measurement, ensuring intrinsic galvanic isolation to separate high- and low-voltage circuits, enhancing safety. Its inherent Electromagnetic Compatibility (EMC) eliminates the noise challenges associated with NTC wires.

The SMD packaging supports automated PCB-based assembly, drastically simplifying production. Designed for resilience, it has a wide ambient operating temperature range of -40°C to 125°C. For precise thermal management in applications like inverter busbar monitoring, the MLX90637 delivers a superior 0.02°C resolution and a fast response time It offers a 50° Field of View (FoV).

The device is factory-calibrated with constants stored in its EEPROM, allowing external calculation of object and ambient temperatures. It maintains accurate measurements by being highly resistant to localized thermal variations and incorporates an optical filter (2 to 20 µm pass band) for ambient light immunity.

The sensor operates on a 3.3V supply voltage and supports 3.3V I²C bus voltage for communication.

Application examples:

• Power semiconductor surface temperature (e.g. traction inverter)
• Bus bar monitoring (e.g. traction inverter)
• Stator/rotor temperature measurement
• Cooling circuits thermal management (e.g. traction inverter, battery pack, ECUs)
• HVAC in-cabin temperature