K4N56163QF Datasheet, PDF (72/73 Pages) Samsung semiconductor – 256Mbit gDDR2 SDRAM

K4N56163QF-GC
256M gDDR2 SDRAM
gDDR2 SDRAM Default Output Driver V–I Characteristics
gDDR2 SDRAM output driver characteristics are defined for full strength default operation as selected by the EMRS1 bits
A7-A9 = ‘111’. Figures 1 and 2 show the driver characteristics graphically, and tables 1 and 2 show the same data in tabu-
lar format suitable for input into simulation tools. The driver characteristics evaluation conditions are:
Nominal Default 25 ^oC (T case), VDDQ = 1.8 V, typical process
Minimum TBD ^oC (T case), VDDQ = 1.7 V, slow–slow process
Maximum 0 ^oC (T case), VDDQ = 1.9 V, fast–fast process
Default Output Driver Characteristic Curves Notes:
1) The full variation in driver current from minimum to maximum process, temperature, and voltage will
lie within the outer bounding lines of the V–I curve of figures 1 and 2.
2) It is recommended that the ”typical” IBIS V–I curve lie within the inner bounding lines of the V–I curves
of figures 1 and 2.
Table 3. Full Strength Calibrated Pulldown Driver Characteristics
Calibrated Pulldow n Current (mA)
Voltage (V)
Nominal Minimum
(21 ohms)
Nominal Low
ohms)
(18.75Nominal
(18
ohms)
Nominal High (17.25 Nominal Maximum (15
ohms)
ohms)
0.2
9.5
10.7
11.5
11.8
13.3
0.3
14.3
16.0
16.6
17.4
20.0
0.4
18.7
21.0
21.6
23.0
27.0
Table 4. Full Strength Calibrated Pullup Driver Characteristics
Calibrated Pullup Current (mA)
Voltage (V)
Nominal Minimum
(21 ohms)
Nominal Low
ohms)
(18.75Nominal
(18
ohms)
Nominal High
ohms)
(17.25Nominal Maximum
ohms)
(15
0.2
-9.5
0.3
-14.3
0.4
-18.7
-10.7
-16.0
-21.0
-11.4
-16.5
-21.2
-11.8
-17.4
-23.0
-13.3
-20.0
-27.0
gDDR2 SDRAM Calibrated Output Driver V–I Characteristics
gDDR2 SDRAM output driver characteristics are defined for full strength calibrated operation as selected by the proce-
dure outlined in Off-Chip Driver (OCD) Impedance Adjustment. Tables 3 and 4 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 ohm 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 as repre-
sented 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 cali
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Rev 1.6 (Apr. 2005)