'Institute of Electrical and Electronics Engineers (IEEE)'
Doi
Abstract
This paper presents a scalable and ultrasensitive
frequency-shift magnetic biosensing array scheme. The
theoretical limit of the sensor noise floor is shown to be
dominated by the phase noise of the sensing oscillators. To
increase the sensitivity, a noise suppression technique, Correlated Double Counting (CDC), is proposed with no power overhead. As an implementation example, a 64-cell sensor array is designed in a standard 65nm CMOS process. The CDC scheme achieves an additional 6dB noise suppression. The magnetic sensing capability of the presented sensor is verified by detecting micron size magnetic particles with an SNR of 14.6dB for a single bead and an effective dynamic range of at least 74.5dB