Translinear Subthreshold MOS Filter for the Wireless Sensors Applications

Abstract

The work describes a design of the filter using log-domain CMOS technology. Filter only consists of capacitances and CMOS transistors in the week inversion mode and they are treated in the subthreshold conduction region. Low-pass, band-pass and high-pass filter is considered in the design. The transfer function of the filter is determined by the feedback around its input and output. My design is based on demand to have a universal building block which is able to filter the frequency band from DC to radio frequencies. This building block is represented by the log-domain differentiator. The frequency band and the transfer function of the filter is determined only aid few devices connected to this building block. It is intended to use these current-mode filters in the design of the wireless sensor systems. In these applications the low-pass filters are usually used as an anti-aliasing filter before the signal is sampled. Also the radio frequency part of the circuit uses the filters. The program CADENCE and 0.18 ?m CMOS technology were used for simulations.