0 Replies Latest reply on Dec 7, 2013 2:58 PM by bmah

    Worst case Junction Temperature of Sync SRAMs

    bmah

       The absolute maximum junction temperatue of Sync SRAM is 125 deg C and the junction temperature can be calculated from the following link: http://www.cypress.com/?docID=23984 .The calculated junction temperature should be less than 125 deg C.

         

      We can also calculate the worst case junction temperature which can be calculated using the same tool under the worst case conditions. For example, consider the Sync SRAM CY7C2665KV18-550BZXC. The worst case Tj can be calculated by substituting the following values in the tool:

         

      Vdd=1.9 (max), Idd =1520 mA (X36, Idd at max frequency), α=1, f=550 MHz, CL = 5pf (Tested load), Number of Switching IOs=36, Vddq=1.9(max), No of ODT inputs=42, R=50 Ohm, Ta=70 deg C, Theta Ja= 12.55 . This would give the value of Tj as 122.6 deg C. This can be considered as the worst case Tj and the recommended maximum value of Tj.