Low-voltage high-speed current-mode continuous-time IC filters withorthogonal Ω0-Q tuning

摘要

The design of fully differential high-frequency continuous-timencurrent-mode filters is presented. A universal biquad is constructednfrom two basic building blocks, lossless and lossy differentialncurrent-mode integrators, Pole frequency Ω0 and qualitynfactor Q are tuned orthogonally by means of a translinear circuit. Thendesign is illustrated on a 200-MHz fifth-order cascade low-pass filter.nThe tuning scheme is used to switch the transfer function electronicallynfrom a Butterworth to a Bessel characteristic. The proposed circuits usena single-ended supply that can be as low as 1.5 V with no specialntechnology required. The design was implemented in an 8-GHz bipolarnprocess