Title :
An improved source-follower based Sallen-Key continuous-time biquadratic cell with auxiliary path
Author :
Resta, F. ; D´Amico, S. ; De Matteis, M. ; Baschirotto, A.
Author_Institution :
Dept. of Innovation Eng., Univ. of Salento, Lecce, Italy
Abstract :
An improved Source Follower based low-pass Sallen-Key continuous time biquadratic cell is presented. An innovative structure with auxiliary path is proposed in order to increase the out-of-band attenuation of Sallen-Key filter. The auxiliary path eliminates one out-of-band parasitic zero in the transfer function. A prototype of Sallen-Key second order filter with a bandwidth of 120MHz and a quality factor of 1.19 has been designed in a standard 0.35μιη technology occupying 390μιη X 222μm area. A 75dB HD3 for a IV input signal and 50dB out-of-band attenuation at 3.2GHz are the filter peculiarity. The cutoff frequency deviation due to technological spread, aging and temperature variation is adjusted by using 4-bits capacitors arrays.
Keywords :
biquadratic filters; continuous time filters; low-pass filters; operational amplifiers; transfer functions; 4-bits capacitors arrays; Sallen-Key second order filter; auxiliary path; bandwidth 120 MHz; cutoff frequency deviation; filter peculiarity; out-of-band attenuation; out-of-band parasitic zero; size 0.35 mum; source follower based low-pass Sallen-Key continuous time biquadratic cell; transfer function; voltage 1 V; Low-pass filter; Sallen-Key filter; out-of-band attenuation;
Conference_Titel :
NORCHIP, 2014
Conference_Location :
Tampere
DOI :
10.1109/NORCHIP.2014.7004729
