On the feasibility of SI for low-power VLSI biomedical signal processing

Low-power analogue-sampled-data (ASD) signal processing has traditionally relied on the well-known switched capacitor (SC) technique for the implementation of medical implants, hearing instruments and/or interfaces for battery operated instrumentation. In this paper recent advances in the rapidly maturing switched-current (SI) technique are reviewed with respect to their feasibility for application in novel circuit structures that set the foundations of low-power SI for biomedical signal processing (BSP) and other applications. A qualitative comparison is made between class A and AB SI cells and the mode of MOS transistor operation. The authors briefly discuss building blocks for novel continuously tuneable filtering structures that rely on transconductance-ratios rather than capacitor ratios. Biologically inspired implementations of the cochlea illustrate possible applications