Digitizing the feedback signal in a magnetic field (AMR) sensor system using delta sigma modulator topology

Delta-Sigma modulation is a technique that is widely used for high accuracy analog to digital conversion. In this paper a method for a high resolution sensor system will be introduced by integrating the sensor as a delta element in a delta sigma modulator system. This proposed method is optimized for data acquisition purpose in a magnetic field sensor system using an AMR sensor. By analyzing the output bit-stream, which represents the feedback signal for the sensor, the input magnetic field can be determined. The modulator used is a first order modulator. The whole system operates at a power supply voltage of 1.5 V and is being realized in a 0.35 μm CMOS technology.