CMOS digitally programmable cell for high frequency amplification and filtering

This paper presents an approach to the implementation of systems combining variable gain amplifiers (VGA) and programmable continuous-time G_m-C filters in the video frequency range. The technique relies on the use of a versatile high-performance transconductance amplifier as an active cell. Simulation results from 35 μm designs supplied at 3.3 V show a 0 to 16 dB gain setting range for the VGA, while G_m-C integrators present a wide tuning range (10 to 100 MHz), with no degradation of the dynamic range (better than 60 dB) and low excess phase (<0.5°) over the whole tuning range.