A 120-MHz Active-RC Filter with an Agile Frequency Tuning Scheme in 0.18-μm CMOS
Journal
IEEE VLSI-DAT
Pages
208-211
Date Issued
2008-04
Author(s)
Abstract
A wideband active-RC low-pass filter realized for high data rate wireless receivers is reported in this paper. This filter adopts the 5th-order elliptic topology and achieves a bandwidth of 120 MHz and a stopband attenuation of more than 45 dB. The wide-bandwidth operational amplifiers employed in the filter adopt the feedforward compensation technique to extend the unity-gain bandwidth to 4.1 GHz. An agile tuning scheme is also proposed to automatically adjust the filter cutoff frequency. It uses the successive approximation register counter in the digital tuning loop to compensate for the RC variations while achieves short calibration time. The filter is fabricated in the TSMC 0.18-μm CMOS process and dissipates 38 mW under 1.5-V supply voltage. The measured IIP3 is 21 dBm and the tuning time is 8 μs. ©2008 IEEE.
SDGs
Type
conference paper