Technology Generic Delta-Sigma ADC Design with gm/ID Methodology

In contrast to traditional Operational Transconductance Amplifiers (OTAs), ring amplifiers present notable advantages in terms of superior performance and ease of scaling, rendering it a favored choice in analog circuit design. However, it is hard to use traditional hand-calculation in determining its optimal sizing, posing a substantial challenge for designers in sizing the ring amplifier. To address these challenges, this paper introduces a systematic gm/ID-based design method for the self-biased ring amplifier, which is automated within the analog design tool TED. The feasibility of the design procedure is verified through simulations using 65nm and 180nm technologies. Furthermore, the proposed design methodology is applied to a practical Delta-Sigma Modulator (DSM) design, resulting in over 100dB SNDR and 100kHz bandwidth.