A Low-Power Mixed-Mode SIMO Universal Gm–C Filter

Abstract

This paper describes a new single-input multiple-output (SIMO) mixed-mode universal biquad [Formula: see text]–[Formula: see text] filter. It can realize all kinds of filter responses including high-pass, band-pass, low-pass, band-stop and all-pass filters, simultaneously. Moreover, in this structure, all of these filters in all states of voltage mode, current mode, transresistance mode and transconductance mode are achieved by the same topology without any convertor. The proposed filter employs three operational transconductance amplifiers (OTAs) with four inputs and one output, three fully differential OTAs and two grounded capacitors. In other words, this filter is composed of six [Formula: see text] blocks and two grounded capacitors. The grounded capacitors are suitable for integrated circuit implementation. In order to reduce the power consumption, the OTAs are biased in subthreshold region. In addition, sensitivity analysis is included to show the low active and passive sensitivity performances of the filter. This filter is designed and simulated in HSPICE with 0.18[Formula: see text][Formula: see text]m model CMOS technology parameters. The simulation results show that the filter consumes only 75[Formula: see text][Formula: see text]W and operates at 1.5[Formula: see text]MHz with [Formula: see text]0.5[Formula: see text]V supply voltages and capacitors [Formula: see text][Formula: see text]pF.