db9 contact resistance

[certs]

I need to figure what the contact resistance of a db9 connector (male) contact resistance is?

Do you where i can get the information?

 

[47gandalf]

Contact resistance is usually specified by the manufacturer for a mated pair of contacts. When I worked on automatic test equipment for torpedos, the military connectors used were specified as having a maximum resistance per mated pair of 3 milliohms, for example. The value is a function of variables like the contact material, mating force, geometry (contact area and shape), number of mating cycles, etcetera.

This parameter is a subtle and important way to distinguish connector families. Basically, you get what you pay for. Or really, you pay for what you get. So commercial contacts have higher contact resistance than military contacts, but cost less.

When you have cabling or connections that lead to a signal passing through multiple contacts with high current, the I*R losses can add up suprisingly. And when you add this resistance to the model of your circuit, it can affect things like the corner frequency of filters or the gain of op amp circiuts.

I'd suggest you look at the applications information for some top notch connector manufacturers. AMP is a good one. They make darned near every type of connector.