Voltage-mode PAM4 driver with differential ternary R-2R DAC architecture

Abstract

A voltage-mode pulse-amplitude modulation 4 (PAM4) driver with differential ternary R-2R DAC architecture is described. The differential ternary R-2R DAC provides three voltage levels with one R-2R branch, whereas the conventional one provides only two. Therefore, much less R-2R branches are required for a given number of output voltage levels. One of the three voltage levels is realised by simply short circuiting a differential input pair, saving power consumption. Implemented in 65 nm CMOS technology, the voltage-mode PAM4 driver occupies 0.073 mm(2) active silicon area and consumes 1.97 mW/Gbit/s from 1.0 V supply at 10 Gbit/s.