This paper reports a monolithic device integrating a CMOS analog front-end and an array of 192 MR sensors for biomolecular recognition detection. Innovative CMOS building blocks (i.e. current source, multiplexers and pre-amplifier) were designed targeting a negligible noise when compared with the MR sensors noise and a low power consumption. The CMOS front-end was fabricated using AMS 0.35 μm technology and the magnetoresistive sensors were post-fabricated on top of the CMOS chip. Due to its low noise (16 nV/√Hz), the full system was able to detect magnetic nanoparticles with a SNR degradation of only 1.4 dB (circuit imposed). Furthermore, the unprecedented low power consumption (6.5 mW) and small dimensions (7.59 mm2) of the presented solution guarantees the portability of the detection system allowing its usage at the point-of-care.
['Tiago Costa', 'J. Germano', 'Moisés Piedade', 'Filipe Arroyo Cardoso', 'P. P. Freitas']
Design and optimization of a CMOS front-end for magnetoresistive sensor based biomolecular recognition detection