Title :
A 500-nA sixth-order bandpass SC filter
Author :
Castello, Rinaldo ; Grassi, Alberto G. ; Donati, Stefano
Author_Institution :
Dept. of Electron., Pavia Univ., Italy
fDate :
6/1/1990 12:00:00 AM
Abstract :
A sixth-order bandpass switched-capacitor (SC) filter that requires only 500 nA of total supply current has been designed and fabricated in a 2-μm CMOS technology. The filter is part of an implantable device powered by a ±1.2-V battery; it can drive up to 30 pF of capacitive load and uses a 2-kHz sampling frequency. A substantial reduction in the power consumption has been achieved by using a novel amplifier time-sharing technique that allows the realization of an arbitrary number of biquadratic cells with only two amplifiers. Further power saving was obtained with the use of positive feedback in the amplifier input stage to enhance its transconductance. The prototype chip requires an area of 2200 mils2
Keywords :
CMOS integrated circuits; active filters; band-pass filters; switched capacitor filters; 2 kHz; 2 micron; 500 nA; CMOS technology; amplifier input stage; amplifier time-sharing technique; biquadratic cells; capacitive load; implantable device; positive feedback; power consumption; sampling frequency; sixth-order bandpass SC filter; total supply current; transconductance; Band pass filters; Batteries; CMOS technology; Current supplies; Energy consumption; Feedback; Frequency; Power amplifiers; Sampling methods; Time sharing computer systems;
Journal_Title :
Solid-State Circuits, IEEE Journal of
