title: A New Fully Differential CMOS Capacitance to Digital Converter for Lab-on-Chip Applications.
abstract: In this paper, we present a new differential CMOS capacitive sensor for Lab-on-Chip applications. The proposed integrated sensor features a DC-input ΣΔ capacitance to digital converter (CDC) and two reference and sensing microelectrodes integrated on the top most metal layer in 0.35 μm CMOS process. Herein, we describe a readout circuitry with a programmable clocking strategy using a Charge Based Capacitance Measurement technique. The simulation and experimental results demonstrate a high capacitive dynamic range of 100 fF-110 fF, the sensitivity of 350 mV/fF and the minimum detectable capacitance variation of as low as 10 aF. We also demonstrate and discuss the use of this device for environmental applications through various chemical solvents.
authors.forename: Ghazal
authors.initials: G
authors.lastname: Nabovati
authors.forename: Ebrahim
authors.initials: E
authors.lastname: Ghafar-Zadeh
authors.forename: Maryam
authors.initials: M
authors.lastname: Mirzaei
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Ayala-Charca
authors.forename: Falah
authors.initials: F
authors.lastname: Awwad
authors.forename: Mohamad
authors.initials: M
authors.lastname: Sawan
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D025802:Electric Capacitance; D004867:Equipment Design; D056656:Lab-On-A-Chip Devices; D012666:Semiconductors