Signal Integrity and Radiated Emission of High-Speed Digital Systems

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High-Speed Digital Devices

For many calculations or simulations of Signal Integrity (SI) and Radiated Emission (RE) effects, it is very important to know the input/output (I/O) static and dynamic characteristics of digital devices. The aim of this chapter is to highlight the basic characteristics of the main logic families: Transistor–Transistor Logic (TTL), Complementary Metal Oxide Semiconductor (CMOS) logic, and Emitter-Coupled Logic (ECL). The intention is to provide a background to understand the latest development of components for high-speed applications. How to build up a linear or a simple behavioral model that takes into account the non-linear effects of the driver and receiver is outlined. This must also be considered a starting point for building up more accurate behavioral models. The chapter ends with an introduction of the IBIS models. IBIS is a standard for a fast and accurate behavioral method for modeling I/O buffers based on I/V curve data derived from measurements or full-circuit simulations. An example is given of the use of this type of model by SPICE.

2.1 Input/Output Static Characteristic

In this section the main parameters of the digital technologies are presented to find out the I/O static characteristics of a device. The objectives of the component manufacturers are to improve speed by minimizing the transistor size and to decrease the power consumption by lowering the value of the voltage supply. Other modifications to improve the performance of the ...