Ultrasensitive detection platform for sensing magnetic and/or electrical energy change

Abstract

A scalable and ultrasensitive frequency-shift magnetic 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 described with no power overhead. As an implementation example, a 64-cell sensor array is designed in a standard 65 nm CMOS process. The CDC scheme achieves an additional 6 dB noise suppression. The magnetic sensing capability of the presented sensor is verified by detecting micron size magnetic particles with an SNR of 14.6 dB for a single bead and an effective dynamic range of at least 74.5 dB. Applications in biosensing are contemplated, among other possible uses. Measurement of electrical properties is also contemplated.