A novel tunable transconductance amplifier based on voltage-controlled resistance by MOS transistors

A new tunable transconductance amplifier is proposed for the programmable analog signal processing or low power filter applications. The transconductor linearization is based on the compensation of nonlinear behaviour by two MOS transistors. The transconductance amplifier in this brief exhibits the good common-mode dynamic range and the voltage-controlled transconductance. HSPICE circuit simulation using 0.18-[micro]m standard CMOS technology shows the [+ or -] 50% tunable transconductance range with the [+ or -] 0.2-V control voltage, and the linearity of less than 60 dB in the total harmonic distortion for the 0.6 [V.sub.PP] input signal. Index Terms--Analog MOS integrated circuits, tunable amplifiers, tunable filters, voltage-controlled conductance.