Live demonstration: A CMOS ASIC for precise reading of a Magnetoresistive sensor array for NDT

Non-destructive testing (NDT) based on eddy currents (EC) is commonly used to detect defects in conductive materials. Usually the system includes an emitter coil, and one receiver coil or one Magnetoresistive (MR) sensor. In this work we added an interface ASIC that pre-amplifies and filters the signal from an array of MR sensors. This demo will present a new version based on the work presented at the ECNDT 2014 conference with a paper entitled “A CMOS ASIC for Precise Reading of a Magnetoresistive Sensor Array for NDT”. Since this is an on-going work, improvements have been made, namely the reduction of the system thermal noise to 30 nV/√Hz, the development of a multigain amplifier and the application of the same concept and circuit to a multichannel parallel signal acquisition system. Detection of surface and buried defects will be demonstrated in different material mock-ups.