An incremental A/D converter for accurate vector probe measurements

In this paper we propose an A/D converter for smart sensor read-out systems with limited bandwidth. The system can be associated with various sensors in the case where digital output and high resolution are required. The converter is intended to be cointegrated with IC compatible microsensors. An application of the proposed A/D converter is demonstrated in combination with a two dimensional magnetic vector probe for accurate measurement of the angle of a magnetic field parallel to the chip plane. A two dimensional magnetotransistor serves as sensing element. The converter can be configured to achieve the angle calculation with good accuracy. This system is designed to be used in automotive and drive applications. We successfully implemented the proposed A/D converter in a standard 2 μm CMOS technology together with a two dimensional magnetic vector probe