GIUSEPPE FERRI, NICOLA GUERRINI, STEFANO DEL RE, FABRIZIO MANCINI
Dipartimento di Ingegneria Elettrica, Universit di L Aquila, Localit Monteluco di Roio, 67040 Poggio di Roio, L Aquila, Italy
In this work we present new current mode-based portable interfaces for resistive gas sensors. The proposed low-voltage (supply voltage: 1.5 V, being 1.2 V the minimum operating value) low-power (about 0.15 mW) CMOS interfaces, which includes a grounded resistive sensor, show the capability of compensation of non-idealities of passive and active components, in particular the voltage offset. The sensitivity value has been set to about 0.1 V/K ?, while theoretical resolution is about 7 ?, to which corresponds a gas resolution lower than 1 ppm.
Analog design research has recently pushed towards the implementation of new topologies working at reduced supply voltages and showing low power consumption, especially in portable-system applications such as biomedical, telecommunications and sensor interfaces.
The current-mode approach and, in particular, the second generation current conveyor (CCII) have assumed a stronger importance in low-voltage (LV) low-power (LP) analog integrated circuit design, because the use of current as signal carrier allows to implement new topologies showing excellent LV LP performance [1]. CMOS technology is particularly suitable for these applications, because of its improved sensitivity, small sizes and reduced costs.
The particular application presented in this work is related to resistive gas sensor interfaces. We have considered a sensor named TGS 822 (produced by FIGARO) [2], formed by a thin film of S nO 2, which has...
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