A 21-Gb/s 87-mW Transceiver With FFE/DFE/Analog Equalizer in 65-nm CMOS Technology

A 21-Gb/s backplane transceiver has been presented. The transmitter incorporates half-rate topology with purely digital blocks to substantially reduce power consumption. The receiver employs analog and decision-feedback equalizers in a full-rate structure to avoid complicated structure. The one-tap decision-feedback equalizer merges the summer and the slicer into the flipflop, shortening the feedback path and speeding up the operation considerably. Fabricated in 65-nm CMOS, the transceiver (excluding clock generating PLL and CDR circuits) delivers 21-Gb/s data (2³¹- 1 PRBS) over 40-cm FR4 channel while consuming 87 mW from a 1.2-V supply.