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Article: Dual amplifier designs increase the accuracy of current-feedback amps. (high-speed integrated circuits) (includes related article on design of current-feedback amplifiers) (Tutorial)
- Article from:
- EDN
- Article date:
- December 9, 1993
- Author:
CopyrightCOPYRIGHT 1993 Reed Business Information, Inc. (US). This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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Single current-feedback amplifiers aren't the best choice for high-speed circuits that also require high accuracy. However, circuits that-take advantage of the characteristics of dual current-feedback amplifiers improve accuracy while maintaining high bandwidth.
Designers value the current-feedback amplifier (CFA) for its high slew rates, relatively constant--3-dB bandwidth for different closed-loop gains, and fidelity at high frequencies. However, the unassisted CFA is almost useless in high-accuracy circuits. Although the CFA's errors don't badly distort the signals they carry, they do produce calibration errors, even in 8-bit systems. With video ADCs and DACs ...