Modules for gigahertz digital testing of ECL

A family of high-speed, low-cost multiplexer and data capture circuits is introduced. These hybrid circuits are based on previously introduced principles and are used to extend the upper frequency limits of existing test systems. The modules are based on low-cost ECL technology yet support testing up to about 1 Gpbs. Multiplexers with typical edge rates of 500 ps are demonstrated. Subnanosecond-wide data bits are captured with either a multi-pass sampling circuit or a single-pass demultiplexer. The family of modules includes a variety of reusable circuits for pattern generation and data capture. Through 8:1 pin multiplexing, the paper demonstrates extension of a 200 MHz host system to beyond 1 GHz. These modules have been used in limited cases at frequencies about 1.5 GHz