Advances in neural interface systems require circuit techniques that achieve low noise, ultra-low power consumption, and compact area while scaling to large channel counts. Multiple architectural and circuit strategies have been developed to improve the area and power efficiencies. Multielectrode arrays for in vitro studies introduce additional requirements, including support for electroporation and impedance spectroscopy. Closed-loop neuromodulation systems further demand strong robustness to stimulation artifacts to enable reliable, simultaneous recording and stimulation. This paper reviews state-of-the-art neural interface technologies spanning both sensing and stimulation, highlighting key architectural and circuit innovations across in vivo neural probes, multimodal MEAs, and closed-loop neuromodulation systems.
