EBE21UE8AFFA Datasheet, PDF (21/30 Pages) Elpida Memory – 2GB Unbuffered DDR2 SDRAM DIMM

EBE21UE8AFFA
11. When the device is operated with input clock jitter, this parameter needs to be derated by the actual
tJIT(per) of the input clock. (output deratings are relative to the SDRAM input clock.)
For example, if the measured jitter into a DDR2-667 SDRAM has tJIT(per) min. = −72ps and
tJIT(per) max. = +93ps, then tRPRE min.(derated) = tRPRE min. + tJIT(per) min. = 0.9 × tCK(avg) − 72ps
= +2178ps and tRPRE max.(derated) = tRPRE max. + tJIT(per) max. = 1.1 × tCK(avg) + 93ps = +2843ps.
12. When the device is operated with input clock jitter, this parameter needs to be derated by the actual
tJIT(duty) of the input clock. (output deratings are relative to the SDRAM input clock.)
For example, if the measured jitter into a DDR2-667 SDRAM has tJIT(duty) min. = −72ps and
tJIT(duty) max. = +93ps, then tRPST min.(derated) = tRPST min. + tJIT(duty) min. = 0.4 × tCK(avg) −
72ps = +928ps and tRPST max.(derated) = tRPST max. + tJIT(duty) max. = 0.6 × tCK(avg) + 93ps =
+1592ps.
13. Refer to the Clock Jitter table.
14. tWTR is at least two clocks (2 × tCK or 2 × nCK) independent of operation frequency.
Data Sheet E1458E20 (Ver. 2.0)
21