A novel LV LP CMOS internal topology of CCII+ and its application in current-mode integrated circuits
ABSTRACT In this paper we present a novel internal architecture of low-voltage and low-power positive second-generation current conveyor (CCII+). The proposed internal circuit topology, designed in standard CMOS technology (AMS 0.35 Â¿m), employs an n-type differential pair as input stage, while a cascoded push-pull configuration implements a very high impedance output stage. A degenerated nMOS common drain topology reduces X node impedance. The choice of internal CCII+ architecture, concerning both its stage architecture and transistor sizes, has been made in the direction of designing a quasi-ideal CCII+ in terms of parasitic components at its terminals. The developed CCII+ operates at low supply voltages of Â±1 V with a total power consumption of about 300 Â¿W, so it is suitable for general purpose portable applications. It has been also characterized implementing well-known applications, both in time and frequency domains, such as signal processing circuits and impedance simulators.
Article: WO3 Hydrogen resistive gas sensor and its wide-range current-mode electronic read-out circuit[show abstract] [hide abstract]
ABSTRACT: Tungsten oxide (WO3) thin films have been prepared via Sol-Gel route by spinning (WCl6 in ethanol, 0.2M) on Pt interdigitated Si/Si3N4 substrates and annealed at 300°C for 12, 24, 96 and 200 hours respectively. Films morphology and crystalline phase have been characterized through SEM, AFM and glancing angle XRD. The increasing of the annealing time shows a positive effect on the degree of crystallization but with no substantial influence on the crystallite size, surface area and mean roughness of the films. Electrical tests have been carried out utilizing a current-mode dedicated read-out circuit to perform gas-sensing measurements of the polycrystalline WO3 films to H2 gas (0–250ppm) in dry air and operating temperatures ranging from 25°C to 250°C. Electrical tests have confirmed a n-type response of the films. Although improved sensitivity (S=RA/RSENS) has been achieved when decreasing the annealing time, best performances in terms of reproducibility and long term stability of the response have been obtained by annealing the film for 200 hours at 300°C temperature.IEEE Sensors Journal 04/2013; Early Access Articles. · 1.52 Impact Factor