Sub-mW reconfigurable interface IC for electrochemical sensing

The IronIC project has the aim of developing a fully implantable and remotely powered platform for the real-time monitoring of human metabolites. In this paper we present a mixed-signal interface IC for the electrochemical sensing data acquisition chain. The IC controls and reads out up to five biomolecular sensors, by receiving commands from a standard interface to conduct chronoamperometry (CA) and cyclic voltammetry (CV). Different voltage profiles are generated by using a single fully on-chip reconfigurable waveform generator, while the measured data are digitized. The IC is realized in 0.18 µm CMOS technology. Electrical measurements show that the linear readout current range is ±1650 nA with 8-bit resolution. The cyclic voltammetry of potassium ferricyanide and the chronoamperometry of hydrogen peroxide have been successfully performed with the interface. The IC consumes 0.92 mW from 1.8 V supply voltage, making it suitable for remotely powered and implantable applications.