ARTICLES BY RALPH MORRISON
Limiting Radiation from Logic Circuit Boards.
Once energy leaves a controlled path, the chances are it will cause interference and radiate from board edges.
The energy that flows on a logic circuit board leaves as heat and/or electromagnetic radiation. As clock rates have risen, radiation has become more of an issue. The logic voltage levels we view are at the end points of transmission lines. To move logic signals we need to understand how nature moves energy. There are no energy meters, so we must rely on theory to understand how to limit radiation. This is the same theory that governs all electrical behavior. The control of radiation is not complicated but it is different than circuit theory. 12 October 2018. At printed circuit design and fab
Maxwell and Transmission Lines
The famous mathematician can guide our understanding of electrical signals.
Maxwell's famous equations describing electricity were published in 1868. Many historians feel this is the greatest contribution ever made to science. Maxwell had none of the components or instruments we know today. The fact that these equations agree with relativity theory is even more amazing. These equations are field-based because that is the side of nature that could be observed. The genius was to express these field ideas as concise differential equations. 6 December 2018. At pcdandf
What is Electronics My definition of electronics is: The smooth flow of electromagnetic field energy in conducting structures to perform specific electrical tasks. This energy should not leave the circuit except at planned points. Note that a component is a conducting structure. May 3, 2018 electronics-related.com
Voltage - A Close Look We measure voltage in fast circuits and we may not realize all the things that the voltage can represent. Until someone invents an energy meter, voltage is the only observation tool we have. May 23, 2018. electronics-related.com
Voltage in the GHz World
Understand what is happening to the energy moving around in a circuit board.
I want to challenge your understanding of electricity. My intentions are honorable. Technology is asking us to move more and more data, which in turn requires the use of more and more bandwidth. The tools we use have evolved from circuit theory, where we were very comfortable using lumped parameter models. Today, the interconnecting structures on logic circuit boards are just as important as the components. How a board is laid out controls delays, radiation and bit rates. I feel the meaning of voltage when it involves fast logic needs to be given a closer look. 08 May 2018. At pcdandf
The Layout of Fast Logic on Printed Circuit Boards
In PCB transmission lines, a correct design can render leakage negligible.
There is a struggle going on related to building fast logic circuit boards. Designs fail because they radiate or will not function at the required clock rate. Explaining why one approach works and another fails brings out some strange explanations. Herein, we discuss this design problem using well-known principles. New science is not needed. New language is not needed. What will be said will probably surprise readers, however, as this area of electrical behavior is often poorly understood. 12 March 2018. At pcdandf