DDR1 and DDR2 SDRAM
Table 14 provides the recommended operating conditions for the DDR SDRAM component(s) when
GV (typ) = 2.5 V.
DD
Table 14. DDR SDRAM DC Electrical Characteristics for GV
(typ) = 2.5 V
DD
Parameter
Symbol
Min
Max
Unit
Notes
I/O supply voltage
GV
MV
2.375
2.625
V
V
1
2, 5
3
DD
I/O reference voltage
I/O termination voltage
Input high voltage
0.49 × GV
0.51 × GV
DD
REF
TT
DD
V
MV
– 0.04
+ 0.18
MV
+ 0.04
REF
V
REF
REF
V
MV
GV + 0.3
V
—
—
4
IH
DD
Input low voltage
V
I
–0.3
MV
– 0.18
REF
V
IL
Output leakage current
–40
–15.2
15.2
40
μA
mA
mA
OZ
OH
Output high current (V
= 1.9 V)
I
—
—
—
—
OUT
Output low current (V
= 0.38 V)
I
OL
OUT
Note:
1
GV is expected to be within 50 mV of the DRAM GV at all times.
DD
DD
2
MV
noise on MV
is expected to be equal to 0.5 × GV , and to track GV DC variations as measured at the receiver. Peak-to-peak
DD DD
REF
may not exceed ±2% of the DC value.
REF
3
V
is not applied directly to the device. It is the supply to which far end signal termination is made and is expected to be
TT
equal to MV . This rail should track variations in the DC level of MV
.
REF
REF
4
5
Output leakage is measured with all outputs disabled, 0 V ≤ VOUT ≤ GV
See AN3665, MPC837xE Design Checklist, for proper DDR termination.
.
DD
Table 15 provides the DDR capacitance when GV (typ) = 2.5 V.
DD
Table 15. DDR SDRAM Capacitance for GV
(typ) = 2.5 V
Max
DD
Parameter
Symbol
Min
Unit
Notes
Input/output capacitance: DQ, DQS
C
6
8
pF
pF
1
1
IO
Delta input/output capacitance: DQ, DQS
C
—
0.5
DIO
Note:
1
This parameter is sampled. GV = 2.5 V ± 0.125 V, f = 1 MHz, T = 25°C, V
= GV /2, V
(peak-to-peak) = 0.2 V.
DD
A
OUT
DD
OUT
Table 16 provides the current draw characteristics for MV
.
REF
Table 16. Current Draw Characteristics for MV
REF
Max
Parameter
Current draw for MV
Symbol
Min
Typ
Unit
Note
I
μA
1, 2
REF
MVREF
DDR1
DDR2
—
—
250
150
600
400
Note:
1
The voltage regulator for MV
must be able to supply up to the stated maximum current.
REF
2
This current is divided equally between MVREF1 and MVREF2, where half the current flows through each pin.
™
MPC8378E PowerQUICC II Pro Processor Hardware Specifications, Rev. 2
Freescale Semiconductor
17
FREESCALE [ Freescale ]
