Instantaneous Clock Recovery with Multi-Bit-Rate Fucntionality for High-Speed Communication and Switching Applications

Period of Performance: 04/16/1998 - 10/15/1998


Phase 1 SBIR

Recipient Firm

Conductus, Inc.
969 W. Maude Avenue
Sunnyvale, CA 94085
Principal Investigator


The increased complexity of the modern electronics increases size. which reduces speed because of time delays in the interconnects. As a result. for frequencies above a few GHz, asynchronous communication between subsets of a complex system is unavoidable. The disadvantage of this approach is the need to recover the phase (clock) of the digital signal, which for semiconductor circuits requires a few thousand clock periods. Recovering the phase of multi-bit-rate signals is even more difficult. A clock recovery circuit with locking time of one bit has been developed at Conductus which makes it available for asynchronous communication even with multi-bit-rate signals. For Phase I of the project Conductus will develop and test the clock recovery circuit at frequencies up to 40 GHz. The chip will be fabricated using TRW niobium nitride (NbN) technology on a subcontract basis. and tested at Conductus. Conductus will also design the optimum architecture for the multi-bit-rate clock recovery system, which will have a frequency recognition unit with short detection time. For Phase II of the effort, Conductus will propose to develop a complete integrated clock recovery unit. operating at 10K. supporting multiple bit rates, and packaged in a closed-cycle refrigerator.