Development of Analytical Behavioral Models for Digitally Controlled Edge Interpolator (DCEI) based Digital-to-Time Converter (DTC) Circuits

Digital-to-time converter (DTC) circuits enable various applications in the area of frequency synthesis. Phase interpolator (PI) circuits are popular DTC fine tuning elements, however, their high nonlinearity is a major drawback. This work investigates PIs and aims at increasing their linearity, resolution, and operation frequency. Therefore, PI linearity is analyzed and modeled analytically. Different PI-based DTCs with up to 13 bit resolution were implemented in three test chips, fabricated in 28nm CMOS technology.