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Altera_Forum's avatar
Altera_Forum
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18 years ago

Measuring SSN

Hi, i have seen people trying to measure SSN with the toggling aggressors on the FPGA floating (not connected to anywhere). How accurate is that compared to aggressors with load?
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
18 years ago

You must have load caps in a SSO measurement. the discharge from the load capacitors flowing back into the device are what cause the ground bounce event. The larger the load the larger the bounce event. You need to choose the load that best represents what you expect as trace and load capacitance in your application.