Summary: Duobinary signaling has been introduced into asymmetric multi-chip communications such as DRAM or display interfaces, which allows a controlled amount of ISI to reduce signaling bandwidth by 2/3. A × 2 oversampled equalization has been developed to realize Duobinary signaling. Symbol-rate clock recovery form Duobinary signal has been developed to reduce power consumption for receivers. A Duobinary transmitter test chip was fabricated with 90-nm CMOS process. A 3.5 dB increase in eye height and a 1.5 times increase in eye width was observed.