New fully differential instrumental chain for Hall sensor signal conditioning integrated in standard 0.35 μm CMOS process

This paper describes a new integrated fully differential analogue instrumental chain dedicated to magnetic field measurement. This chain features a silicon Horizontal Hall Device, high CMRR low thermal noise instrumentation amplifiers as well as a modulation - demodulation system based on the chopper stabilized technique operated at 100 kHz. This allows offset and 1/f noise cancellation by multistage high-pass filtering. The system achieves 10 muT resolution (experimental) over a 3.6 kHz bandwidth by applying 100 kHz spinning current to the Hall Device.