Vehicle sensor measures very low pressure

An automotive-qualified relative pressure sensor from Melexis, the MLX90821 measures fuel vapor pressure as low as 50 mbar and as high as 700 mbar. The sensor IC is well-suited for evaporation (EVAP) systems designed for internal combustion and hybrid engines, as it is able to detect even the smallest leaks that can potentially appear at any point in the EVAP system.

The MLX90821 is calibrated during the final steps of manufacture, with the pressure transfer curve and clamping levels stored in internal EEPROM. Measurement data is delivered as a ratiometric analog output or a digital signal using the SENT protocol. With an external NTC sensor, the MLX90821 can also provide compensated temperature measurements of the media being monitored.

Housed within the system-in-package is the MEMS pressure sensor manufactured through backside etching, analog front and backend circuitry, a 16-bit microcontroller, and voltage regulators. The MLX90821’s easy-to-seal packaging is certified for operation over a temperature range of -40°C to +150°C and comes with Production Part Approval Process (PPAP) support.

Features

  • High accuracy relative pressure sensor with ratiometric analog output or digital SENT output including compensated ±1°C accurate NTC media temperature information
  • Large automotive temperature range (-40°C to 150°C)
  • Automotive qualified and automotive diagnostic features (clamping levels, broken track diagnostics, multiple internal fault diagnostics)
  • Factory calibrated or fully programmable or reconfigurable through the connector for customized calibration curves at customers
  • Backside exposed relative pressure sensor for higher resistance to common automotive media
  • Assembled in a robust easy-to-seal package

>> An earlier version of this article was originally published on our sister site, EDN: “Vehicle sensor measures very low pressure.”

 

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