Design of a New Concept Pressure Sensor for X-by-wire Automotive Applications

Although the automotive market is slowly moving towards electro- mechanical X-by-Wire systems for low and middle class vehicles, there is still a significant need for electro-hydraulic systems in high power braking and steering applications. Therefore, an ongoing development in the direction of more precise, reliable and cost effective systems is taking place. Consequently, the performances of the respective sensorial systems have to enhance. Hence justifying the development effort for new concepts for MEMS pressure sensors. Moreover, many of the servo- assisted electro-hydraulic applications operate in two pressure ranges: a low range, where high precision is needed, and a high pressure one, where stability is a primary requirement. Normally these characteristics can only be fulfilled by using two pressure sensors with two different ranges. In this paper, a silicon pressure sensor with a two levels sensitivity that aims to meet the described specifications in one sensor design is presented. Moreover, self-test and recalibration are conceived in the design in order to enhance reliability and precision at a cost effective way.