0.342 nW Class-AB enhanced flipped source follower low pass filter for biomedical applications.

Area of Science:

• * Electrical Engineering
• * Biomedical Engineering
• * Signal Processing

Background:

• * Designing low-power low-pass filters (LPFs) with improved linearity is crucial for effective biological signal processing, yet challenging due to process voltage and temperature variations.
• * Existing LPF designs often struggle to balance power consumption, linearity, and performance in low-voltage environments.

Purpose of the Study:

• * To present the design and simulation of a fourth-order Class-AB enhanced flipped source follower (EFSF) LPF circuit.
• * To target the specific application of electroencephalography (EEG) signal detection.
• * To achieve high power efficiency for future low-voltage and low-power biological systems.

Main Methods:

• * Design of a fourth-order Class-AB EFSF LPF circuit using complementary metal-oxide-semiconductor (CMOS) 180 nm technology node.
• * Simulation performed using Cadence Analog Design Environment.
• * Robustness verified through Monte Carlo simulations (200 runs).

Main Results:

• * The EFSF LPF achieved a DC-gain of -88 mdB and a bandwidth of 100 Hz.
• * Power consumption was remarkably low at 0.342 nW from a 0.5 V supply.
• * Key performance metrics include a figure of merit of 5.983 × 10^-15 J, dynamic range (DR) of 43.54 dB, and input-referred noise of 91 µV_rms.
• * Monte Carlo simulations confirmed the robustness with mean values for DC-gain, DR, and total harmonic distortion of -188.09 mdB, 43.10 dB, and -41.85 dB, respectively.

Conclusions:

• * The proposed Class-AB EFSF LPF demonstrates excellent performance in terms of low power consumption and linearity.
• * The circuit is suitable for effective electroencephalography signal detection.
• * This design offers a viable solution for high power efficiency in future low-voltage and low-power biological applications.