Correlation of measurement and simulation for simultaneous switching noise of FPGA

FPGAs (Field Programmable Gate Array) are now widely used for prototyping systems as well as mid-volume products. These FPGAs are fabricated by the leading edge CMOS process technology. These may excite false logic transition due to simultaneous switching CMOS output buffers. In this paper, simultaneous switching noise of FPGA was investigated by both measurement and simulation. First, a precise circuit model was established by extracting the leadframe inductance of the package and including on-chip decoupling capacitance. The power supply impedance of an evaluation board was also simulated. Then, measured waveforms were compared with time-domain simulated results. The simulated time-domain waveforms showed a good agreement with measured waveforms. Moreover, ringing frequency of the measured waveforms was well correlated with the peak of the power supply impedance.