A low-voltage and low-power sinh-domain universal biquadratic filter for low-frequency applications

Abstract: Sinh-domain CMOS filters have favorable properties, such as a wide dynamic range at low supply voltage, compactness, linearity, and low power consumption. These properties are becoming increasingly important for biomedical applications that require extremely low-power dissipation and neuromorphic circuits that attempt to reproduce the biophysics of biological neurons and synapses. In this paper, a low-voltage sinh-domain universal biquadratic filter circuit is introduced. The circuit, aside from permitting the independent adjustment of pole frequency (ω0) and the quality factor (Q), is free from matching conditions, capable of absorbing the shunt parasitic capacitances, amenable for monolithic integration, and composed of merely a few transconductor cells and grounded elements. The other features of the circuit are its low sensitivity and good linearity. Simulated results are obtained to prove the theoretical analyses and the filter shows a dynamic range of 59.17 dB and power consumption of only 19.2 nW.