1 Factors Influencing SSN
(Ask a Question)Microchip performed a number of SSN experiments to understand the likelihood of SSN affecting the device performance. The following information is based on a real test data taken from Microchip SX-A and RTSX-SU FPGAs.
As the device ground is within the package, it is hard to measure the actual internal ground bounce. The most common way to measure ground bounce is to configure an output to drive low (or high for VCC bounce) and observe it using an oscilloscope.
In-house measurements and validation were done with reference to MIL-STD-883. The device being tested was soldered onto a custom board. High-bandwidth oscilloscopes, upwards of 1G samples per second, were used for this purpose. Typical conditions were used in making all measurements. According to the specification, all switching outputs (including the quiescent output) were loaded with a 50Ω resistor to ground in parallel with a 50 pF capacitor.