A new interfacing method 'SCFL-interfacing' is proposed for ultra-high-speed logic ICs

摘要

A new I/O interfacing method called 'SCFL-interfacing' as a standard interfacing for ultra-high speed logic ICs. The purpose is to avoid the waveform degradation and further difficulties inherent in conventional ECL-interfacing when operating above 1 Gb/s. Characteristics of the proposed method include: (1) high and log I/O levels of typically 0.0 V and -0.9 V, respectively; (2) on-chip 59 ohm resistors as receiving-end terminators; and (3) signal distributor ICs for multi-fanout connections. The authors strongly believe that SCFL-interfacing is highly effective for ICs operating above 10 Gbit/s. However, as a first step, to insure compatibility with conventional ICs, they developed an 8 Gb/s GaAs standard logic IC family using a modified SCFL-interfacing in which both SCFL and ECL interfaces are available.