Floating-gate based tunable CMOS low-voltage linear transconductor and its application to HF g/sub m/-C filter design

This paper presents a new CMOS low-voltage linear transconductor for Very High Frequency (VHF). It uses multiple-input floating-gate transistors (MIFGTs) in each inverter that forms the differential transconductor presented by Nauta (1992). The proposed transconductor operates under constant low-voltage supply as low as 1.2 V and its transconductance and output resistance are independently tunable. It is suitable for use in HF continuous time filters with programmable center frequency and quality factor. To this end, simulation results of a 10.7 MHz and Q=40 g/sub m/-C filter operating with a voltage supply of 1.4 V and with rail-to-rail input swing are presented.