A 12-bit 2.5 GHz 0.37ps-Peak-INL Digital-to-Time Converter with Parasitic-Insensitive Charge-Based Phase Interpolator

A 12-bit 2.5GHz digital-to-time converter (DTC) for high resolution and high linearity applications is presented in this paper. The DTC is segmented into a 4-bit coarse stage and an 8-bit fine stage. The proposed fine stage utilizes parasitic-insensitive charge-based (PICB) phase interpolator (PI) with significant improvement in linearity. The PICB PI outputs 50% duty cycle differential clock and its performance is insensitive to parasitic effect. The DTC is designed in 40nm CMOS technology and consumes 7.1mW with a 1.1-V supply voltage. Simulation results show that the peak integral nonlinearity and differential nonlinearity are 0.37ps and 0.085ps, respectively.