Title :
A 40–200 MHz programmable 4th-order Gm-C filter with auto-tuning system
Author :
Otin, A. ; Celma, S. ; Aldea, C.
Author_Institution :
Univ. of Zaragoza, Zaragoza
Abstract :
A CMOS 40-200 MHz 4th-order Gm-C Butterworth filter with an automatic tuning system for both frequency and quality factor is presented. Constant-capacitance scaled Gm-C integrators features a technique leading to a wide transconductance tuning range. A compact dummy-based scheme is also incorporated in the design to maintain the integrating capacitance constant over all the programming range. The filter is based on Gm-C biquads and the experimental results in a low-cost pure digital 0.35 mum CMOS process have shown a dynamic range of 58 dB for THD<-40 dB with a single 2 V supply. The cut-off frequency is digitally programmable in the range of 40-200 MHz. An automatic tuning system for both characteristic cut-off frequency and Q-factor is used to compensate for process and temperature parameter variations.
Keywords :
Butterworth filters; CMOS digital integrated circuits; Q-factor; biquadratic filters; circuit tuning; integrated circuit design; programmable circuits; CMOS Butterworth filter; Gm-C biquads; Q-factor; auto-tuning system; automatic tuning system; constant-capacitance scaled Gm-C integrators; digital CMOS process; frequency 40 MHz to 200 MHz; process variations; programmable 4th-order Gm-C filter; quality factor; size 0.35 mum; temperature parameter variations; voltage 2 V; Circuit optimization; Cutoff frequency; DVD; Dynamic range; High speed optical techniques; Optical filters; Optical pulse shaping; Q factor; Transconductors; Tuning;
Conference_Titel :
Solid State Circuits Conference, 2007. ESSCIRC 2007. 33rd European
Conference_Location :
Munich
Print_ISBN :
978-1-4244-1125-2
DOI :
10.1109/ESSCIRC.2007.4430283
