Internet Data Sheet
HYB18TC256[80/16]0BF
256-Mbit Double-Data-Rate-Two SDRAM
TABLE 54
ODT AC Characteristics and Operating Conditions for DDR2-667 and DDR2-800
Symbol
Parameter / Condition
Values
Unit
Note
Min.
Max.
1)
tAOND
tAON
ODT turn-on delay
2
2
nCK
ns
1)2)
1)
ODT turn-on
tAC.MIN
tAC.MAX + 0.7 ns
tAONPD
tAOFD
tAOF
ODT turn-on (Power-Down Modes)
ODT turn-off delay
t
AC.MIN + 2 ns
2 tCK +
t
AC.MAX + 1 ns
ns
1)
2.5
2.5
nCK
ns
1)3)
1)
ODT turn-off
tAC.MIN
tAC.MAX + 0.6 ns
tAOFPD
tANPD
tAXPD
ODT turn-off (Power-Down Modes)
ODT to Power Down Mode Entry Latency
ODT Power Down Exit Latency
t
AC.MIN + 2 ns
2.5 tCK +
t
AC.MAX + 1 ns
ns
1)
3
8
—
—
nCK
nCK
1)
1) New units, “tCK.AVG” and “nCK”, are introduced in DDR2-667 and DDR2-800. Unit “tCK.AVG” represents the actual tCK.AVG of the input clock
under operation. Unit “nCK” represents one clock cycle of the input clock, counting the actual clock edges. Note that in DDR2-400 and
DDR2-533, “tCK” is used for both concepts. Example: tXP = 2 [nCK] means; if Power Down exit is registered at Tm, an Active command may
be registered at Tm + 2, even if (Tm + 2 - Tm) is 2 x tCK.AVG + tERR.2PER(Min)
.
2) ODT turn on time min is when the device leaves high impedance and ODT resistance begins to turn on. ODT turn on time max is when
the ODT resistance is fully on. Both are measured from tAOND, which is interpreted differently per speed bin. For DDR2-667/800, tAOND is
2 clock cycles after the clock edge that registered a first ODT HIGH counting the actual input clock edges.
3) ODT turn off time min is when the device starts to turn off ODT resistance. ODT turn off time max is when the bus is in high impedance.
Both are measured from tAOFD, which is interpreted differently per speed bin. For DDR2-667/800, if tCK(avg) = 3 ns is assumed, tAOFD is 1.5
ns (= 0.5 x 3 ns) after the second trailing clock edge counting from the clock edge that registered a first ODT LOW and by counting the
actual input clock edges.
Rev. 1.3, 2007-05
54
07182006-DD60-22E6
QIMONDA [ QIMONDA AG ]
