For 7 Series and Zynq-7000 devices, is it okay to use Tantalum capacitors for the 100 uF capacitors used for PCB Decoupling?
Table 2-4 in the 7 Series FPGAs PCB Design and Pin Planning Guide (UG483), and Table 3-3 in the Zynq-7000 SoC PCB Design and Pin Planning Guide (UG933) both specify "2-Terminal Ceramic X7R or X5R" capacitors for the 100 uF capacitors.
However, Tantulum capacitors are okay to use as a substitute. This may be important if the temperature range requirements exceed what is available in the Ceramic chip capacitors.
The main consideration for substitutions is that the other parameters are met, primarily the ESL Maximum, ESR range, and minimum Voltage Rating. Page 20 of UG483, and page 15 of UG933 states:
"The tantalum and niobium oxide capacitors specified in Table 2-4/Table 3-3) were selected for their values and controlled ESR values.
They are also ROHS compliant. If another manufacturers tantalum, niobium oxide, or ceramic capacitors are used, the user must ensure they meet the specifications of Table 2-4/Table 3-3 and are properly evaluated via simulation, s-parameter parasitic extraction, or bench testing."