All-digital CDR for high-density, high-speed I/O

A novel all-digital CDR for source-synchronous links, and its implementation in 90nm CMOS, is presented. A phase alignment technique with ping-pong action between two clock phases is used. The system is implemented in static CMOS logic, occupies 0.234 mm 2 and dissipates 16.6 mW at 6 Gb/s, demonstrating BER −13 with PRBS-7 input. The compactness and all-static-CMOS nature of the system make it suitable for use in high-speed I/Os requiring per-pin synchronization.