Melexis has introduced the first of its new line of commercial, off the shelf, packaged MEMs pressure sensors. The MLX90809 is a highly accurate, AEC Q100 qualified relative pressure sensor specifically targeted at 1 Bar applications. The company’s proprietary piezo-resistive MEMS technology with a high accuracy sensing element, low noise analogue front end and 16-bit sigma-delta analogue-to-digital converter (ADC) combine to offer an impressive level of performance.
The resulting sophisticated analogue chain provides the necessary amplification and offset compensation for the sensing element. The built-in 16-bit microcontroller unit (MCU) deals with temperature compensation and supplies the diagnostic mechanisms required for safety critical applications.
An integrated fully programmable EEPROM memory allows different configurations to be supported, such as independent setting of diagnostic functions for over-voltage or under-voltage supply conditions and over-pressure or under-pressure conditions, as well as selectable digital filter settings to further reduce output noise or alternatively to decrease sensor response time. It also permits sensor compensation data and unit identity to be stored.
“As the MEMS technology employed is fully compatible with standard CMOS processes, we have been able to fabricate a completely monolithic sensor, where the sensing element and its signal conditioning circuitry are processed on the same wafer,” Laurent Otte, Product Marketing Manager for Pressure Sensors at Melexis, explains. “This gives the device a huge advantage over non-integrated pressure sensor offerings, where the signal conditioning is normally several millimeters away from the sensing element and therefore exhibits inferior signal integrity and greater susceptibility to electro-magnetic interference (EMI). It also allows us to reduce the die area to less than half that of our previous generation of integrated MEMs based pressure sensors.”
Offered in a highly robust, plastic molded, 16-pin surface mount package, the MLX90809 sensor device can deliver pressure data via an analog output voltage ratiometric to the supply voltage or using the SENT digital protocol. It has an operational temperature range of -40 °C to +150 °C, enabling it to cope with the most demanding automotive environments.