Title :
A 30MHz 28dBm-IIP3 3.2mW fully-differential Sallen-Key 4th-order filter with out-of-band zeros cancellation
Author :
Resta, F. ; De Matteis, M. ; Pezzotta, A. ; D´Amico, S. ; Baschirotto, A.
Author_Institution :
Phys. Dept., Univ. of Milano-Bicocca, Milan, Italy
Abstract :
In this paper a 4th-order 30MHz Butterworth low-pass analog filter is presented, exploiting the Sallen-Key (SK) biquadratic cell circuit. The out-of-band zeros typically present in SK cells, are cancelled by using a low-power auxiliary path, resulting in a significant improvement of the stopband rejection, at the cost of a small power budget for the same auxiliary path biasing. An efficient unity gain buffer has been used, based on super-source-follower stage, providing very large in-band IIP3 over the entire filter bandwidth (21.5dBm for 25MHz&26MHz input tones), at 3.2mW power consumption from a single 1.8V supply voltage. The filter prototype has been designed in CMOS 0.18μm tech. The total area occupancy is 0.12mm2, the in-band integrated noise is 197μVRMS.
Keywords :
Butterworth filters; CMOS integrated circuits; biquadratic filters; low-pass filters; low-power electronics; poles and zeros; Butterworth low-pass analog filter; CMOS tech; Sallen-Key biquadratic cell circuit; auxiliary path biasing; frequency 25 MHz; frequency 26 MHz; frequency 30 MHz; fully-differential Sallen-Key 4th-order filter; in-band integrated noise; low-power auxiliary path; out-of-band zeros cancellation; power 3.2 mW; power consumption; size 0.18 mum; stopband rejection; super-source-follower stage; voltage 1.8 V; Out-of-Band zeros; Sallen-Key Filter; Super-Source-Follower;
Conference_Titel :
New Circuits and Systems Conference (NEWCAS), 2015 IEEE 13th International
Conference_Location :
Grenoble
DOI :
10.1109/NEWCAS.2015.7182066
