A Dynamic Current Pulsing Technique to Improve the Noise Efficiency Factor of Neural Recording Amplifiers

Low noise and low power neural recording amplifiers are required for implantable devices measuring action potentials. This paper presents a dynamic current pulsing technique combined with a special type of two-stage low-pass filter (LPF) that demonstrates an improvement in the noise efficiency factor (NEF) beyond that achievable using traditional design. A low NEF of 1.55 is achieved at an average power consumption of 587.8 nW and 5.18 µVrms noise, integrated from 0.1 to 9.8 kHz, inclusive of the impacts of sampling and aliasing. The NEF is improved from 1.76 in the static low current state (LCS) and 1.67 in the static high current state (HCS), measured on the same amplifier chip.