The research team headed by Associate Professor Chen Mingyi from the National Key Laboratory of Micro/Nano Fabrication Technology at the School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, has made substantial advancements in the realm of high dynamic range analog-to-digital converter chips for brain-computer interfaces (BCIs). Recently, the team published a groundbreaking paper titled "A 26-GΩ Input-Impedance 112-dB Dynamic-Range Two-Step Direct-Conversion Front-End With Improved Δ-Modulation for Wearable Biopotential Acquisition" in the prestigious IEEE Journal of Solid-State Circuits (JSSC). This publication introduces, for the first time, a direct-conversion analog front-end chip with a dynamic range exceeding 110dB, specifically tailored for BCIs.

Manufactured using a 180nm standard CMOS process, the chip boasts an impressive input impedance of 26GΩ and a remarkable high dynamic range of 112dB, marking a significant 20dB improvement over current technologies. Furthermore, the chip is capable of withstanding artifacts and DC offsets of up to ±1.8V, with an artifact withstand amplitude that is 30 times higher than traditional analog front-ends with comparable gain, all while consuming only 63μW of power. This innovative technology not only addresses critical challenges in non-invasive BCIs but also holds potential applications in invasive BCIs, significantly enhancing the system's resilience to stimulation artifacts.