Fully integrated rectification and bin-integration analog circuit for biomedical signal processing

In this paper, we describe the simulation and measurement results of a fully integrated low-voltage CMOS rectification and bin-integration (RBI) module based on switched-capacitor and dedicated to nerve signal (Electroneurogram) acquisition and processing. RBI is the most common signal processing function applied to the nerve signals and since the frequency of these signals is relatively low, switched-capacitor architecture has been used. The proposed device comprises a new always-valid output sample-and-hold block followed by a full wave rectifier and a three-stage bin-integrator. The integrated circuit has been realized in CMOS 0.35 mm technology. The design, simulation and measurement results of the proposed module are presented. At plusmn1.3 V supply, the device delivers an RBI error of less than -45 dB for a sine wave input of 7.2 kHz that is the main component of the nerve signal and an output dynamic range of plusmn1.1 V while dissipating 578 muW and occupying a silicon area of 5.83 mm².