Title :
Improving the bandwidth gain-independence and accuracy of the current feedback amplifier
Author :
Gift, Stephan J G ; Maundy, Brent
Author_Institution :
Dept. of Electr. & Comput. Eng., Univ. of the West Indies, St. Augustine, Trinidad and Tobago
fDate :
3/1/2005 12:00:00 AM
Abstract :
A high-performance current feedback amplifier circuit referred to as an operational current feedback amplifier is described in this paper. The technique employed involves the incorporation of the input circuit of the current feedback amplifier in the feedback loop of an operational amplifier to reduce the input impedance at the inverting terminal of the current feedback amplifier. The new circuit possesses the gain accuracy and bandwidth of the current feedback amplifier but realizes significant improvement in bandwidth accuracy and bandwidth gain-independence. Experimentally, using AD844s, an order of magnitude reduction in bandwidth variation with changing gain was achieved in the noninverting configuration and almost complete bandwidth invariance was realized in the inverting configuration.
Keywords :
circuit feedback; high-speed integrated circuits; operational amplifiers; AD844; analog processing circuits; bandwidth accuracy; bandwidth gain-independence; bandwidth invariance; feedback loop; gain accuracy; high-speed integrated circuits; input impedance; noninverting configuration; operational amplifier; operational current feedback amplifier; Bandwidth; Electronic circuits; Feedback amplifiers; Feedback circuits; Feedback loop; Helium; High speed integrated circuits; Impedance; Operational amplifiers; Transfer functions; Analog processing circuits; current feedback amplifier; high-speed integrated circuits; operational amplifier;
Journal_Title :
Circuits and Systems II: Express Briefs, IEEE Transactions on
DOI :
10.1109/TCSII.2004.842043
