A T-coil-enhanced 8.5Gb/s high-swing source-series-terminated transmitter in 65nm bulk CMOS

Implemented in 65nm bulk CMOS, the 8.5Gb/s transmitter exhibits an eye height exceeding 1.0V and has a return loss of <-16dB up to 10GHz owing to the use of 40×40μm2 T-coils that are applied to the 1.5V-operated thick-oxide output slices. The equalization consists of a 5b 2-tap FIR filter whose adaptation is orthogonal to that of the impedance tuning. A duty-cycle restoration capability of 5x is achieved. The chip consumes 96mW at 8.5Gb/s and occupies 180×360μm2. ©2008 IEEE.