A GaAs SONET framer IC for broadband subscriber loop applications

An experimental prototype high-speed SONET (Synchronous Optical Network) framer IC designed for possible broadband subscriber loop applications is presented. The experimental prototype IC, implemented in a GaAs enhancement/depletion (E/D) MESFET technology, performs 8:1 multiplexing, 1:8 demultiplexing, byte alignment, and SONET frame detection functions. The chip operates at data rates up to 1.244 Gb/s (SONET STS-24) over a temperature range from -40 degrees to +85 degrees C. The experimental prototype IC contains approximately 4000 transistors, dissipates 2.5 W of power, and has an estimated yield of about 50%. This performance demonstrates the feasibility of using GaAs LSI in broadband subscriber loop applications where high speed, high density, and low temperature sensitivity are required.<
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