Resistor selection app-note from Ohmite


In all of my undergraduate and graduate career, information pills I have had very little introduction to passive component selection. Most of what I know come at the expense of poor designs and from Bob Pease’s book on troubleshooting analog circuits. It should be known that resistors typically have small associated capacitances and inductances which can lead to strange circuit effects, however, this application note focuses mostly on selecting the right resistor based on power rating.

As circuits get smaller, using a something as small as a 0201 format resistor becomes fairly attractive. The downside (there are always downsides!) is that as the package size goes down, so does the power rating. Other factors, like enclosure and cooling, can change the rated dissipation limit. Although the app note covers many of these factors, they also provide a useful “shortcut” sheet on the seventh page to simplify the possible de-rating calculations for a particular circuit design. This information is still missing from many third year EE circuit design courses, so hopefully this PDF will provide an adequate supplement.

( appnotes_res_select.pdf )

One thought on “Resistor selection app-note from Ohmite

  1. Pingback: μblog: engineering from the trenches » Impedance measurement handbook from Agilent

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