Integrated instrumental chain for magnetic pulse measurement in strong static field environment

Abstract

This paper describes an integrated analogue instrumental chain dedicated to measuring magnetic pulses with an amplitude of a few tens or hundreds of microteslas, superimposed to a strong static magnetic field, i.e. 1.5T. The system features a silicon Hall sensor with biasing circuitry, DC Hall voltage compensation, amplifying and multistage filtering. Low-noise performances are achieved by applying 100kHz spinning current to the Hall device and chopping at 200kHz to the signal conditioning blocs downstream. The microsystem achieves 20 μT resolution over a 1.6kHz bandwidth extending from 5Hz to 1.6kHz under 1.5T static field.