Mathcad files

Papers

The Ground Plane: Lord of the Board	183k	First published in the EMC Journal issue 72, September 2007; discusses the implementation of ground planes on PCBs
Measurement Errors Caused by the Transient Limiter	195k	Presented at EMC Zurich (Munich) 07. Subject as below, but with more detail in the modelling.
The hazard of the transient limiter	90k	First published in the EMC Journal issue 69, discusses the errors that can be caused in the CE test by the transient limiter, and what you can do about them.
Advanced Topics in EMC Design	468k	Presented at NEEDS2006 in May 2006, the IEEE EMCS in December 06 and the SCA in July 07, discusses the issues of split ground planes (don't!), decoupling capacitor selection and placement, and common-to-differential mode conversion in interface filters.
Why do I never get the same result twice?	518k	Presented at the SCA meeting on 6th September 05, examines why you may get different results for EMC emissions and immunity tests, even at the same test house on the same day, let alone from different test houses at different times.
The trouble with wall-warts	28k	Originally published in EMC Journal May 05, this discusses the problems due to conducted RF emissions from wall-wart power supplies.
Pitfalls and practice of IEC 61000-4-6 conducted immunity testing	1851k	Written with Richard Marshall and published in EMC Journal March 05, discusses best practice in using CDNs, EM Clamp and current probe in conducted RF immunity tests.
Emissions measurements on switch-mode power supplies	206k	Originally written as an application note for Chase EMC and published in ITEM 1993. Now updated, discusses golden product and pre-compliance testing of SMPS using a spectrum analyser, LISN and various accessories.
Using standards under the second edition	139k	Presentation given at the EMCTLA interactive workshop in London on the New EMC Directive, 19th January 2005.
Shielding effectiveness of a box with a slot	324k (zipped)	PowerPoint 97 presentation showing variation of shielding effectiveness with box size, slot width and measurement position, according to the theory developed by Robinson et al at the University of York. Zip file includes animations derived from Mathcad.
Why broadband PLT is bad for EMC	266k	Unpublished elsewhere, the title says it all. If you are looking at this site on a broadband connection, read this paper and consider. Updated April 05
Aspects of I/O filter design	120k	Presented at Newbury in 2004, discusses how you implement an interface filter and looks at its circuit model. Issues of component balance and CM-to-DM conversion are covered in detail.
Controlling resonances in PCB-chassis structures	364k	Presented in Sorrento in 2002, this paper describes the impact of structural resonances for product EMC and discusses how to control them.
Measurement techniques and test methods	98k	Presented at the ERA EMC-94 conference, is a tutorial for companies who want to invest in their own facilities for in-house EMC testing. Revised March 2000
Using ferrites for interference suppression	184k	This has been written to try and demystify the subject of ferrite sleeves on cables, in our experience one of the least understood aspects of EMC design. Includes several plots of actual ferrite performance.
Conducted interference	113k	This paper was written to clarify the mechanisms involved in conducted coupling, both for emissions and immunity. First presented at an IEE Colloquium in London, entitled "The Hows and Whys of EMC Design", on 30th March 1999
Ground planes on low cost boards	180k	Ground planes are widely used in multilayer boards for high-performance digital circuits, but you can use them on cheap analogue-only boards for improved immunity too.
A critique of the EMC Directive	40k	Presented in Rome in 1996, this paper reviews the operation of the European EMC Directive thus far and makes recommendations for improvements.
EMC and litigation	24k	Presented at Zurich in 1995, describes a case heard at the High Court in which the fundamental issue was the electromagnetic susceptibility of an electronic system.
Response of 74XX logic circuits to ESD transients	77k	Presented at the IEE in 1994, reports the results of some experiments on the ESD susceptibility of various types of flip-flop.
Cost-effective layout of microprocessor circuits	192k	Presented at the ERA EMC-92 conference, covers some of the issues for microprocessor PCB layout and describes a training aid to help in understanding them.

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