Dan Elftmann, Solomon Wolday, Minal Sawant, Cecily Liu, and Richard Chan
Actel Corporation
Abstract
During a particular power cycling of Actel .25µ RT54SX-S FPGA devices, an increased ICCI inrush current will occur. The root cause for the onset of the phenomena was a direct result of a TID enhancement that was included for the two devices in this family. The explanation of the trigger which causes the phenomena to occur during power cycling is straightforward. However, the complete model, characterization, and understanding of the resulting ICCI inrush current is more complex. The factors that affect the amplitude of the ICCI inrush current are temperature, recovery time, residual voltage on the VCCI at power-up, and lot specific leakage current parameters. Both empirical laboratory measurements and SPICE simulations have been completed to enable RT54SX-S FPGA designers a better understanding of the impact on their systems of this increased ICCI inrush current.