A 10 kPixel CMOS Hall Sensor Array With Baseline Suppression and Parallel Readout for Immunoassays

摘要

A CMOS microsystem for detecting microparticles in magnetic immunoassays uses the intrinsic dynamics of magnetization in super-paramagnetic materials to reduce measurement baseline by $> 300times$ compared to conventional methods, and to achieve a $hbox{signal} mathchar"702D hbox{to} mathchar"702D hbox{baseline~ ratio}> 1$, with an improvement of over 50$,times$ compared to systems that ignore bead dynamics. The microsystem integrates a 64$,times,$ 160 Hall-sensor array with column-parallel readout electronics that combine auto-zeroing and nested chopping to enable low-offset, power efficient signal acquisition and has an Allan deviation floor of 9 nT.