Jump resonance: a feedback viewpoint and adaptive circuit solution for low-power active analog filters

Jump resonance is a phenomenon where smooth changes in the input of a nonlinear filter lead to abrupt changes in its output. For over 50 years, research has defined the region of operation where jump resonance can occur so that this region may be avoided by limiting the signal amplitude of operation. This paper provides an intuitive understanding of jump resonance and predicts the behavior of the system in the jump resonance regime. This allows for further tradeoffs between system behavior and power consumption for highly power-efficient filtering systems. Our technique is verified against experimental data. Then we present a system that gracefully adapts its quality factor, avoiding jump resonance in a way qualitatively similar to biology. Finally, we demonstrate an integrated circuit realization. Index Terms--Adaptive-Q, Fukuma-Matsubara, [G.sub.m]-C filter, jump resonance, low power.