Hynix HMP125U6EFR8C-S6 ユーザーズマニュアル
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DDR2 Device Operations & Timing Diagram
4.4.3 Calibrated Output Driver V-I Characteristics
DDR2 SDRAM output driver characteristics are defined for full strength calibrated operation as selected by
the procedure in OCD impedance adjustment. The below Tables show the data in tabular format suitable for
the procedure in OCD impedance adjustment. The below Tables show the data in tabular format suitable for
input into simulation tools. The nominal points represent a device at exactly 18
Ω. The nominal low and nom-
inal high values represent the range that can be achieved with a maximum 1.5
Ω step size with no calibration
error at the exact nominal conditions only (i.e. perfect calibration procedure, 1.5
Ω maximum step size guar-
anteed by specification). Real system calibration error needs to be added to these values. It must be under-
stood that these V-I curves as represented here or in supplier IBIS models need to be adjusted to a wider
range as a result of any system calibration error. Since this is a system specific phenomena, it cannot be
quantified here. The values in the calibrated tables represent just the DRAM portion of uncertainty while look-
ing at one DQ only. If the calibration procedure is used, it is possible to cause the device to operate outside
the bounds of the default device characteristics tables and figures. In such a situation, the timing parameters
in the specification cannot be guaranteed. It is solely up to the system application to ensure that the device is
calibrated between the minimum and maximum default values at all times. If this can’t be guaranteed by the
system calibration procedure, re-calibration policy, and uncertainty with DQ to DQ variation, then it is recom-
mended that only the default values be used. The nominal maximum and minimum values represent the
change in impedance from nominal low and high as a result of voltage and temperature change from the
nominal condition to the maximum and minimum conditions. If calibrated at an extreme condition, the amount
of variation could be as much as from the nominal minimum to the nominal maximum or vice versa. The
driver characteristics evaluation conditions are:
stood that these V-I curves as represented here or in supplier IBIS models need to be adjusted to a wider
range as a result of any system calibration error. Since this is a system specific phenomena, it cannot be
quantified here. The values in the calibrated tables represent just the DRAM portion of uncertainty while look-
ing at one DQ only. If the calibration procedure is used, it is possible to cause the device to operate outside
the bounds of the default device characteristics tables and figures. In such a situation, the timing parameters
in the specification cannot be guaranteed. It is solely up to the system application to ensure that the device is
calibrated between the minimum and maximum default values at all times. If this can’t be guaranteed by the
system calibration procedure, re-calibration policy, and uncertainty with DQ to DQ variation, then it is recom-
mended that only the default values be used. The nominal maximum and minimum values represent the
change in impedance from nominal low and high as a result of voltage and temperature change from the
nominal condition to the maximum and minimum conditions. If calibrated at an extreme condition, the amount
of variation could be as much as from the nominal minimum to the nominal maximum or vice versa. The
driver characteristics evaluation conditions are:
a) Nominal 25
o
C (T case), VDDQ = 1.8 V, typical process
b) Nominal Low and Nominal High 25
o
C (T case), VDDQ = 1.8 V, any process
c) Nominal Minimum TBD
o
C (T case), VDDQ = 1.7 V, any process
d) Nominal Maximum 0
o
C (T case), VDDQ = 1.9 V, any process
Calibrated Pulldown Current (mA)
Voltage (V)
Nominal
Minimum
(21 ohms)
Nominal
Low
(18.75 ohms)
Nominal
(18 ohms)
Nominal
Maximum
(15 ohms)
Nominal
High
(17.25 ohms)
0.2
0.3
0.4
0.3
0.4
9.5
14.3
18.7
18.7
11.5
16.6
21.6
16.6
21.6
10.7
16.0
21.0
16.0
21.0
11.8
17.4
23.0
17.4
23.0
13.3
20.0
27.0
20.0
27.0
Calibrated Pullup Current (mA)
Voltage (V)
Nominal
Minimum
(21 ohms)
Nominal
Low
(18.75 ohms)
Nominal
(18 ohms)
Nominal
Maximum
(15 ohms)
Nominal
High
(17.25 ohms)
0.2
0.3
0.4
0.3
0.4
-9.5
-14.3
-18.7
-18.7
-11.4
-16.5
-21.2
-16.5
-21.2
-10.7
-16.0
-21.0
-16.0
-21.0
-11.8
-17.4
-23.0
-17.4
-23.0
-13.3
-20.0
-27.0
-20.0
-27.0
Table 26. Full strength calibrated pullup driver characteristics
Table 25. Full strength calibrated pulldown driver characteristics