An analog readout circuit with offset calibration for cantiliver-based DNA detection

In this paper a readout circuit for label-free DNA detection based on piezo-resistive MEMS cantilevers is presented. The circuit is designed to have high sensitivity and a precise calibration block in order to deal with possible large variation of the cantilever resistance due to technological mismatch effects. The readout channel has been electrically tested showing, as preliminary results, a total differential dynamic range of 35dB with 15μV as best input resolution, a static offset compensation of about 78dB and a common-mode rejection of about 58dB with about 2.2% of linearity, which demonstrates the suitability of the proposed architecture for the target application. The chip consumes about 10mW from a 3.3V power supply, while the area occupation is of about 1.05mm2 (pad excluded).