A cost-efficient fully synthesizable stochastic time-to-digital converter design based on integral nonlinearity scrambling

Abstract

Stochastic time-to-digital converters (STDCs) are gaining increasing interest in submicron CMOS analog/mixed-signal design for their superior tolerance to nonlinear quantization levels. However, the large number of required delay units and time comparators for conventional STDC operation incurs excessive implementation costs. This paper presents a fully synthesizable STDC architecture based on an integral non-linearity (INL) scrambling technique, allowing order-of-magnitude cost reduction. The proposed technique randomizes and averages the STDC INL using a digital-to-time converter. Moreover, we propose an associated design automation flow and demonstrate an STDC design in 12nm FinFET process. Post-layout simulations show significant linearity and area/power efficiency improvements compared to prior arts.