A1 0k P i x e lC M O SH a l lS e n s o rA r r a yW i t hB a s e l i n e Suppression and Parallel Readout for Immunoassays Simone Gambini,M e m b e r ,I E E E,K a r l S k u c h a, Student Member , IEEE, Paul

Abstract

A CMOS microsystem for detecting micropart icles in magnetic immunoassays uses the intrinsic dynamics of magneti- zation in super-paramagnetic materials to reduce measurement baseline by compared to conventional me thods, and to achieve a signal to baseline ratio , with an improvement of over 50 compared to systems that ignore bead dynamics. The microsystem integrates a 64 160 Hall-sensor array with column- parallel readout electronics that combine auto-zeroing and nested chopping to enable low-offset, power ef ficient signal acquisition and has an Allan deviation floor of 9 nT.