A 0.4-4-Gb/s CMOS quad transceiver cell using on-chip regulated dual-loop PLLs

This paper describes the design and implementation of a quad high-speed transceiver cell fabricated in 0.13-/spl mu/m CMOS technology. The clocking circuit of the cell employs a dual-loop architecture with a high-bandwidth core phase-locked loop (PLL) and low-bandwidth digitally controlled interpolators. To achieve low jitter while maintaining low power consumption, the dual-loop PLL uses two on-chip linear regulators of different bandwidths, one for the core and the other for the interpolator loop. The prototype chip operates from 400 Mb/s to 4 Gb/s with a bit error rate of <10/sup -14/. The quad cell consumes 390 mW at 2.5 Gb/s (95 mW/link) under typical operating conditions with a 400-mV output swing driving double terminated links.