Rev. 0.2 / Jul. 2008 42
HY5PS1G4(8,16)31C(L)FP-xxI
HY5PS1G4(8,16)31CFR-xxI
= + 672 ps. Similarly, tLZ(DQ) for DDR2-667 derates to tLZ(DQ),min(derated) = - 900 ps - 293 ps = -
1193 ps and tLZ(DQ),max(derated) = 450 ps + 272 ps = + 722 ps. (Caution on the min/max usage!)
41. 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 measur ed jitter into a DDR2-667 SDRAM has tJIT(per),min = - 72 ps and tJIT(per),max
= + 93 ps, then tRPRE,min(derated) = tRPRE,min + tJIT(per),min = 0.9 x tCK(avg) - 72 ps = + 2178 ps
and tRPRE,max(derated) = tRPRE,max + tJIT(per),max = 1.1 x tCK(avg) + 93 ps = + 2843 ps. (Caution
on the min/max usage!)
42. 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 = - 72 ps and
tJIT(duty),max = + 93 ps, then tRPST,min(derated) = tRPST,min + tJIT(duty),min = 0.4 x tCK(avg) - 72
ps = + 928 ps and tRPST,max(derated) = tRPST,max + tJIT(duty) ,max = 0.6 x tCK(avg) + 93 ps = + 1592
ps. (Caution on the min/max usage!)
43. When the device is operated with input clock jitter, this parameter needs to be derated by { -
tJIT(duty),max - tERR(6-10per),max } and { - tJIT(duty),min - tERR(6-10per),min } of the actual input
clock.(output deratings are relative to the SDRAM input clock.)
For example, if the measured jitter into a DDR2-667 SDRAM has tERR(6-10per),min = - 272 ps, tERR(6-
10per), max = + 293 ps, tJIT(duty),min = - 106 ps and tJIT(duty),max = + 94 ps, then tAOF,min(derated)
= tAOF,min + { - tJIT(duty),max - tERR(6-10per),max } = - 450 ps + { - 94 ps - 293 ps} = - 837 ps and
tAOF,max(derated) = tAOF,max + { - tJIT(duty),min - tERR(6-10per),min } = 1050 ps + { 106 ps + 272 ps
} = + 1428 ps. (Caution on the min/max usage!)
44. For tAOFD of DDR2-400/533, the 1/2 clock of tCK in the 2.5 x tCK assumes a tCH, input clock HIGH
pulse width of 0.5 relative to tCK. tAOF,min and tAOF,max should each be derated by the same amount as
the actual amount of tCH offset present at the DRAM input with respect to 0 .5. For example, if an input
clock has a worst case tCH of 0.45, the tAOF,min should be derated by subtracting 0.05 x tCK from it,
whereas if an input clock has a worst case tCH of 0.55, the tAOF,max should be derated by adding 0.05 x
tCK to it. Therefore, we have;
tAOF,min(derated) = tAC,min - [0.5 - Min(0.5, tCH,min)] x tCK
tAOF,max(derated) = tAC,max + 0.6 + [Max(0.5, tCH,max) - 0.5] x tCK
or
tAOF,min(derated) = Min(tAC,min, tAC,min - [0.5 - tCH,min] x tCK)
tAOF,max(derated) = 0.6 + Max(tAC,max, tAC,max + [tCH,max - 0.5] x tCK)
where tCH,min and tCH,max are the minimum and maximu m of tCH actually measured at the DRAM input
balls.
45. Fo r tAOFD of DDR2-667/800, the 1/2 clock of nCK in the 2.5 x nCK assumes a tCH(avg), average input
clock HIGH pulse width of 0.5 relative to tCK(avg). tA OF,min and tAOF,max should each be der a ted by the
same amount as the actual amount of tCH(avg) offset present at the DRAM input with respect to 0.5. For
example, if an input clock has a worst case tCH(avg) of 0.48, the tAOF,min should be derated by subtract-
ing 0.02 x tCK(avg) from it, whereas if an input clock has a worst case tCH(avg) of 0.52, the tAOF,max