Micro-Scale Modular CMOS Readout Electronics for Multi-Modal Sensor Arrays

This paper presents a modular readout approach utilizing delta-sigma modulation for sensing applications. Unlike traditional signal chains, which involve oversized components leading to increased power consumption, this approach integrates or connects the sensor directly to the input stage of an ADC. The inherent anti-aliasing characteristic of continuous-time delta-sigma modulators allows sensor signals to be digitized directly, eliminating the need for additional filters reducing system complexity. The method is versatile and applicable to various sensors such as bioelectric electrodes or CMOS stress sensors. This concept enables micro-scale ADC integration on a minimal silicon area, particularly advantageous for needle-shaped neural probes where the electrodes are deposited on the CMOS substrate using MEMS technologies. On-site digitization streamlines external wiring, crucial for large sensor arrays. Ongoing research focuses on flexible substrates for fully integrated micro-scale ADCs, offering a versatile, modular and customizable approach for specific applications.