Active RC filters—A state-space realization

CMOS CCCII: Structures, characteristics, and considerations

“…Obviously, to draft a linear relationship between V XY and i x , the matching condition is p W p L p n W n L n (12) must be satisfied to eliminate the second-order term, which leads to the characteristic equation as…”

“…Therefore, the matching condition in Eq. (12) can only be approximated, which can be achieved by examining n0 and p0 that are provided by fabricators to estimate the ratio between n and p .…”

“…The HSPICE simulations, based on the AMS's 0.35 CMOS process, are conducted variously to support the obtained perceptions. Finally, to observe and compare their performances as a versatile active building block, two-integrator looped circuit is configured as a current-mode equivalence of Tow-Thomas (TT) biquad [12][13][14], which is usually considered as the single most popular biquad in practice [15].…”

Fractional-step Tow-Thomas biquad filters

“…The Tow-Thomas biquad [17][18][19] of Fig. 1 is an active-RC topology used to realize both lowpass and bandpass biquadratic filtering functions.…”

“…1 is an active-RC topology used to realize both lowpass and bandpass biquadratic filtering functions. This topology has been widely used because it is simple, versatile, and requires few components [17]. Analysis of this biquad yields the lowpass and bandpass functions…”