Title :
Digital link pre-emphasis with dynamic driver impedance modulation
Author :
Ranko Sredojević;Vladimir Stojanović
Author_Institution :
Massachusetts Institute of Technology, Cambridge, 02139, USA
Abstract :
Digital push-pull impedance-modulating (RM) pre-emphasis driver overcomes the power overhead of equalization in voltage-mode (VM) drivers, improving the output stage efficiency ∼2–3x. A compact, fully-digital RAM-DAC implementation with pattern lookup compensates both duty-cycle distortion and driver nonlinearity, while providing a programmable pre-emphasis. A testchip fabricated in 90nm CMOS process shows relatively small signal degradation from dynamic modulation of driver output impedance over a variety of 20″ backplanes at 4Gb/s, with energy-efficiency of 2pJ/bit at 100mV of receiver eye.
Keywords :
"Driver circuits","Impedance","Transmitters","Energy efficiency","Degradation","Receivers","Decoding"
Conference_Titel :
Custom Integrated Circuits Conference (CICC), 2010 IEEE
Print_ISBN :
978-1-4244-5758-8
Electronic_ISBN :
2152-3630
DOI :
10.1109/CICC.2010.5617598