ASIC design for a phase sensitive signal conditioning unit for porous silicon based sensors

Porous Silicon (PS) based sensors are compatible to Si IC processing and can be integrated on the same chip with its signal processing unit. PS can be modeled as a distributive RC network and the dielectric constant of the porous layer changes under external stimuli like ambient humidity, pressure etc. Thus a phase sensitive signal conditioning unit that can be integrated with the transducer on the same chip can form an integrated sensor that can detect humidity, pressure, etc. In order to develop the ASIC design for such a phase detecting signal conditioning unit and to perform CAD simulations and verify our design, we have developed a model for the PS transducer. In this paper we discuss the model for the PS transducer that can be incorporated as a SPICE model file for simulation. The SPICE model file incorporates as model parameters the different process and design parameters.