MEMS sensors measure pressure in harsh environments
Combining high sensitivity and strong linearity, two MEMS-based pressure sensors have been introduced by Melexis. The AEC-Q100 qualified MLX90815 and MLX90816 measure absolute pressure in demanding operational environments such as automotive pressure monitoring applications, industrial process controls, domestic appliances, medical equipment and consumer electronics gadgetry.
The MLX90815 is designed for optimal performance when determining pressures from 0 to 30bar absolute, while the MLX90816 covers full scale pressures ranging from 30 to 50bar absolute. Both have a maximum deviation in their linearity of just 0.2%FS. Typical sensitivity for the MLX90815 is 1.5mV/V/bar and for the MLX90816 it is 0.5mV/V/bar.
The sensor element incorporated into every one of these MEMS devices consists of a piezo-resistive Wheatstone bridge connected to a micro-machined silicon pressure membrane, fabricated using Melexis’ own proprietary process technology. As pressure is applied to the membrane, a differential voltage change occurs across the outputs of the Wheatstone bridge while a bias voltage is applied to the bridge inputs.
The MLX90815 and MLX90816 pressure sensors can be supported by the company’s high performance sensor interface chips (such as the MLX90320) in order to carry out conditioning of the output signal.
Each exhibiting an operational temperature range of between -40 and 150°C, the MLX90815 and MLX90816 are able to maintain stable operation in harshest of working conditions. These devices can be employed directly in conventional non-corrosive/non-aggressive media or incorporated into oil-filled sensor modules to further heighten robustness.
Laurent Otte, Product Line Manager, Pressure Sensors, Melexis, comments: “With these latest additions to our product offering, Melexis now reinforces its position as the industry’s one-stop shop for advanced pressure sensing technology. We are not just supplying leading-edge pressure sensors but are also backing this up with an established portfolio of sophisticated interfacing/signal processing ICs to accompany them.”