Design of a Low-power 4th order Composite Folded Flipped Source Follower Filter for Biological Applications

The implementation of the biological healthcare system can greatly benefit from the use of a low-pass filter (LPF) architecture, which is considered to be a highly important architecture. This article, presents a composite folded flipped source follower (FFSF) LPF architecture designed for biomedical signals. The proposed LPF works in the sub-threshold region to attain low-noise and low-power operation. The composite FFSF filter design has been simulated in 0.18 µm complementary metal-oxide semiconductor (CMOS) technology. The proposed architecture delivers -4.2 dB of gain, 100 Hz of bandwidth, 0.79 nW of power, 51 µVrms of input-referred noise and figure of merit of 1.95×10-14 J. The proposed LPF architecture can be used to attain excellent power efficiency in upcoming low-voltage biomedical healthcare systems.