Title :
Temperature stabilised tunable Gm-C filter for very low frequencies
Author :
Bruschi, P. ; Barillaro, G. ; Pieri, F. ; Piotto, M.
Author_Institution :
Dipt. di Ingegneria dell´´Informazione, Pisa, Italy
Abstract :
In this work, a continuous time low pass filter, with sub-Hz upper band limit, is presented. The circuit is based on a Gm-C approach, where the transconductance is stabilised against temperature variations over a wide temperature range (0-80°C) using a DC feedback loop applied to a dummy transconductor (master). The very low transconductance values required to obtain low frequency singularities are achieved by means of multistage current division. A first order low pass prototype filter has been fabricated by means of the 1-μm BCD3S process of STMicroelectronics.
Keywords :
circuit feedback; circuit stability; circuit tuning; continuous time filters; current mirrors; current-mode circuits; low-pass filters; thermal stability; 0 to 80 degC; 1 micron; 75 to 225 mHz; DC feedback loop; Gm-C filter; VLF filter; cascaded current mirrors; continuous time filter; first order low pass filter; low frequency singularities; multistage current division; prototype filter; temperature stabilised filter; transconductance; transconductor; tunable filter; very low frequency filter; Band pass filters; Feedback circuits; Feedback loop; Frequency conversion; Low pass filters; Prototypes; Temperature distribution; Transconductance; Transconductors; Tunable circuits and devices;
Conference_Titel :
Solid-State Circuits Conference, 2004. ESSCIRC 2004. Proceeding of the 30th European
Print_ISBN :
0-7803-8480-6
DOI :
10.1109/ESSCIR.2004.1356629
