A Noise-Efficient Neural Recording Amplifier Using Discrete-Time Parametric Amplification

This letter proposes an instrumentation amplifier for neural recording applications whose measured noise efficiency factor (NEF) is 2.2. A discrete-time parametric amplifier is adopted as a preamplification stage to lower the input-referred noise, thus improving the NEF. The additional induced sampling noise is minimized by oversampling, and the power overhead for switching is minimized by adopting an 8-phase soft-charging technique.