A 2.5-GHz four-phase clock generator with scalable no-feedback-loop architecture

An accurate yet simple multiphase clock generator has been developed by using a delay compensation technique based on phase interpolation that supplies a multiphase clock signal without increasing local circuit area. This generator is applied to the 2.5-GHz four-phase clock distribution of a 5-Gb/s/spl times/8-channel receiver fabricated with 0.13-/spl mu/m CMOS technology. The four-phase generator in the receiver consumes 30 mW and occupies only 0.009 mm/sup 2/. It requires only 1.5 clock cycles to produce accurate phase differences and can operate from 1.5 to 2.8 GHz, with a range of phase error within /spl plusmn/5.