EDE2508ABSE-GE Datasheet, PDF (10/66 Pages) Elpida Memory – 256M bits DDR2 SDRAM for HYPER DIMM

EDE2508ABSE-GE, EDE2516ABSE-GE
ODT DC Electrical Characteristics (TC = 0°C to +85°C, VDD, VDDQ = 1.85V ± 0.1V)
Parameter
Symbol
min.
typ.
Rtt effective impedance value for EMRS (A6, A2) = 0, 1; 75 Ω
Rtt1(eff) 60
75
Rtt effective impedance value for EMRS (A6, A2) = 1, 0; 150 Ω
Rtt2(eff) 120
150
Rtt effective impedance value for EMRS (A6, A2) = 1, 1; 50 Ω
Rtt3(eff) 40
50
Deviation of VM with respect to VDDQ/2
∆VM
−6

Note: 1. Test condition for Rtt measurements.
max. Unit
90
Ω
180
Ω
60
Ω
+6
%
Note
1
1
1
1
Measurement Definition for Rtt(eff)
Apply VIH (AC) and VIL (AC) to test pin separately, then measure current I(VIH(AC)) and I(VIL(AC)) respectively.
VIH(AC), VIL(AC), and VDDQ values defined in SSTL_18.
Rtt(eff) =
VIH(AC) − VIL(AC)
I(VIH(AC)) − I(VIL(AC))
Measurement Definition for VM
Measure voltage (VM) at test pin (midpoint) with no load.
∆VM =
2 × VM
VDDQ
− 1 × 100%
OCD Default Characteristics (TC = 0°C to +85°C, VDD, VDDQ = 1.85V ± 0.1V)
Parameter
min.
typ.
max.
Unit
Notes
Output impedance
12.6
18
23.4
Ω
1
Pull-up and pull-down mismatch
0

4
Ω
1, 2
Output slew rate
1.5

5
V/ns
3, 4
Notes: 1. Impedance measurement condition for output source DC current: VDDQ = 1.7V; VOUT = 1420mV;
(VOUT−VDDQ)/IOH must be less than 23.4Ω for values of VOUT between VDDQ and VDDQ−280mV.
Impedance measurement condition for output sink DC current: VDDQ = 1.7V; VOUT = 280mV;
VOUT/IOL must be less than 23.4Ω for values of VOUT between 0V and 280mV.
2. Mismatch is absolute value between pull up and pull down, both are measured at same temperature and
voltage.
3. Slew rate measured from VIL(AC) to VIH(AC).
4. The absolute value of the slew rate as measured from DC to DC is equal to or greater than the slew rate
as measured from AC to AC. This is guaranteed by design and characterization.
Preliminary Data Sheet E0657E20 (Ver. 2.0)
10