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AR# 18989

PACKAGING - Does Xilinx provide Thermal Resistance ("Psi-JB", "Theta-JC", or "Theta-JB") for Configuration PROMs?


General Description:

"Psi-JB" and "Theta-JC" are available for Xilinx FPGAs and CPLDs. Are they also available for Xilinx Configuration PROMs?


Xilinx characterizes only "Theta-JA" for our PROM families. This is due to the fact that Configuration PROMs do not contribute a significant amount of heat to a system. Configuration PROMs are only active for short amounts of time, the die does not get significantly hot.


Heat sinks are not required for Xilinx PROMs, and Theta-JC is typically useful only when calculating heat sink parameters. Because measurement of Theta-JA is a worst-case, all-encompassing parameter, no other parameters are required if a heat sink is not used.

Theta-JB and Psi-JB

Because PROMs generate so little heat, the overall effect on the board is negligible. For a detailed explanation of the difference between Theta-JB and Psi-JB, see (Xilinx Answer 9088).

AR# 18989
Date Created 09/03/2007
Last Updated 02/08/2013
Status Active
Type General Article