A Programmable Adaptive-Q BPF Circuit

This effort shows the design, measurement, and characterization of a BandPass Filter (BPF) with similar Q adaptation properties seen in the nonlinear dynamics of the basilar membrane in the mammalian cochlea. Starting from low-pass Hopf bifurcations using programmable on-chip Transconductance Amplifiers (TA), a BPF is demonstrated that enables Q adaptation from 25–30 to 1 in roughly 1000 change in amplitude, resulting in a near instantaneous gain adaptation and higher dynamic range. Where the dynamic range of typical BPF banks is limited to the SNR of the individual filter, the adaptive BPF through a Hopf bifurcation enables high dynamic range even with moderate SNR at a given signal level, demonstrated on a large-scale Field Programmable Analog Array (FPAA). This block becomes the basis for higher dynamic range BPFs.