A 4 µW/Ch analog front-end module with moderate inversion and power-scalable sampling operation for 3-D neural microsystems

We report an analog front-end prototype designed for integration into 3-D neural recording microsystems. For scaling towards massive parallel neural recording, the prototype has investigated some critical circuit challenges in power, area, interface, and modularity. The front-end features an extremely low power consumption (4μW/channel), optimized energy efficiency using moderate inversion in low-noise amplifier (K
_LNA
of 5.98×10
⁸
and NEF of 2.9) and programmable-gain amplifier, a minimized asynchronous interface (only 2 per 16 channels) for command and data capturing, a power-scalable sampling and digital operation (up to 50kS/s/channel), and a wide configuration range (9-bit) of gain and bandwidth. The implemented front-end module has achieved a reduction in noise-power-area by a factor of 5-25 times as compared to the-state-of-the-art front-ends reported up to date.