Tire pressure IC is stingy with energy

May 12, 2016 // By CHRISTOPH HAMMERSCHMIDT
Three times lower current in sleep mode than competitors could well be a purchasing argument for a Tire Pressure Monitoring System (TPMS) IC. Melexis’ (Ypres, Belgium) new MLX91804 does not only consume that little energy, it has also a 60% smaller footprint than competing products.

Supplied in a 14-pin DFN type lead-less package, the MLX91804 incorporates a microcontroller and MEMS-based pressure sensing element, as well as energy efficient 315/433MHz wireless transmitter (supporting data rates up to 150kbits/s) and 125kHz receiver for communication with the vehicle’s relevant electronic control unit (ECU). A 16kB embedded program memory accomodates custom application data/libraries. In addition, there is a built-in single or dual axis high-g range accelerometer to support all market available wheel sensor auto-location functionalities.

The combination of minimal footprint and high degrees of integration offered by the MLX91804 means that a significant reduction in PCB size can be realised. Likewise, the device’s low power consumption (in sleep mode as well as when fully operational) permits a downsizing of the specified battery. All this results in a smaller size and lower weight sensor module.

Together with high-g range and fast data acquisition accelerometer, it also represents a step closer to the tire mounted sensor (TMS) implementations that automotive tier 1 suppliers are looking to use in the future. Best in class precision and low power fast pressure measurements allow extra new features to be implemented like tire filling assistant without a visible impact on battery life. The -40°C to 125°C operational temperature range and strong resilience to shock (10,000g) allow the MLX91804 to deal with a harsh in-tire environment.

For more information, visit melexis.com