A new fully differential CMOS capacitance to digital converter for lab-on-chip applications

Ghazal Nabovati, Ebrahim Ghafar-Zadeh, Maryam Mirzaei, Giancarlo Ayala-Charca, Falah Awwad, Mohamad Sawan

Research output: Contribution to journalArticlepeer-review

25 Citations (Scopus)


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 μ m 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.

Original languageEnglish
Article number6876025
Pages (from-to)353-361
Number of pages9
JournalIEEE Transactions on Biomedical Circuits and Systems
Issue number3
Publication statusPublished - Jun 1 2015


  • CMOS
  • Capacitive sensor
  • chemical sensor
  • lab-on-chip
  • ΣΔ modulator

ASJC Scopus subject areas

  • Biomedical Engineering
  • Electrical and Electronic Engineering


Dive into the research topics of 'A new fully differential CMOS capacitance to digital converter for lab-on-chip applications'. Together they form a unique fingerprint.

Cite this