HYB18T1G400AF Datasheet, PDF (70/89 Pages) Infineon Technologies AG – 1 Gbit DDR2 SDRAM

HYB18T1G400/800/160AF
1Gb DDR2 SDRAM
5.4.3 Calibrated Output Driver V-I Characteristics
DDR2 SDRAM output driver characteristics are defined for full strength calibrated operation as selected by the
procedure outlined in the Off-Chip Driver (OCD) Impedance Adjustment. The following tables show the data in
tabular format suitable for input into simulation tools. The nominal points represent a device at exactly 18 ohms.
The nominal low and nominal high values represent the range that can be achieved with a maximum 1.5 ohms
step size with no calibration error at the exact nominal conditions only (i.e. perfect calibration procedure, 1.5 ohm
maximum step size guaranteed by specification). Real system calibration error needs to be added to these values.
It must be understood that these V-I curves are 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 looking 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 figure. In such a situation, the timing parameters in the specifica-
tion 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 proce-
dure, re-calibration policy and uncertainty with DQ to DQ variation, it is recommended that only the default values
to be used. The nominal maximum ad 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 con-
ditions. If calibrated at an extreme condition, the amount of variation could be as much as from the nominal mini-
mum to the nominal maximum or vice versa.
Full Strength Calibrated Pull-down Driver Characteristics
Calibrated Pull-down Driver Current [mA]
Voltage (V)
0.2
Nominal Minimum
(21 Ohms)
9.5
Normal Low
(18.75 Ohms)
10.7
Nominal
(18 ohms)
11.5
Normal High
(17.25 Ohms)
11.8
0.3
14.3
16.0
16.6
17.4
0.4
18.7
21.0
21.6
23.0
The driver characteristics evaluation conditions are:
Nominal 25^oC (Tcase), VDDQ = 1.8 V, typical process
Nominal Low and Nominal High 25^oC (Tcase), VDDQ = 1.8V, any process
Nominal Minimum 95 ^oC (Tcase). VDDQ = 1.7 V, any process
Nominal Maximum 0^oC (Tcase), VDDQ = 1.9 V, any process
Nominal Maximum
(15 Ohms)
13.3
20.0
27.0
Full Strength Calibrated Pull-up Driver Characteristics
Calibrated Pull-up Driver Current [mA]
Voltage (V)
0.2
Nominal Minimum
(21 Ohms)
-9.5
Normal Low
(18.75 Ohms)
-10.7
Nominal
(18 ohms)
-11.4
Normal High
(17.25 Ohms)
-11.8
0.3
-14.3
-16.0
-16.5
-17.4
0.4
-18.3
-21.0
-21.2
-23.0
The driver characteristics evaluation conditions are:
Nominal 25^oC (Tcase), VDDQ = 1.8 V, typical process
Nominal Low and Nominal High 25^oC (Tcase), VDDQ = 1.8V, any process
Nominal Minimum 95 ^oC (Tcase). VDDQ = 1.7 V, any process
Nominal Maximum 0^oC (Tcase), VDDQ = 1.9 V, any process
Nominal Maximum
(15 Ohms)
-13.3
-20.0
-27.0
Page 70
Rev. 1.02
May 2004
INFINEON Technologies