A Low-Power Wideband Reconfigurable Integrated Active-RC Filter With 73 dB SFDR

Abstract

In this paper, a low-power, highly linear, integrated, active-RC filter exhibiting a reconfigurable transfer function (Chebyshev, Elliptic) and bandwidth (5 MHz, 10 MHz), is presented. The filter exploits digitally-controlled polysilicon resistor banks and a digital automatic tuning scheme to account for process and temperature variations. The operational amplifiers used are based on a new compensation technique that allows optimized high-frequency filter performance and minimized current consumption. A filter prototype has been fabricated in a 0.12-mum CMOS process, occupies 0.25 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2 </sup> (tuning circuit included), and achieves an IIP3 of approximately +20 dBm, whereas its spurious free dynamic range (SFDR) reaches 73 dB. The dissipation of the filter core and the tuning circuit is 4.6 mW and 1.5 mW, respectively