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White Electronic Designs Corporation • (602) 437-1520 • www.wedc.com

White Electronic Designs

W3EG6466S-AD4

-BD4

January 2005

Rev. 2

White Electronic Designs Corp. reserves the right to change products or specifications without notice.

PRELIMINARY

DDR SDRAM COMPONENT ELECTRICAL CHARACTERISTICS AND RECOMMENDED AC

OPERATING CONDITIONS

AC CHARACTERISTICS

335

262

265/202

UNITS

NOTES

PARAMETER

SYMBOL

MIN

MAX

MIN

MAX

MIN

MAX

Access window of DQs from CK/CK#

-0.70

+0.70

-0.75

+0.75

-0.75

+0.75

ns

CK high-level width

0.45

0.55

0.45

0.55

0.45

0.55

26

CK low-level width

0.45

0.55

0.45

0.55

0.45

0.55

26

Clock cycle time

CL = 2.5

6

13

7.5

13

7.5

13

ns

39, 44

CL = 2

7.5

13

7.5

13

7.5/10

13

ns

39, 44

DQ and DM input hold time relative to DQS

0.45

0.5

0.5

ns

23, 27

DQ and DM input setup time relative to DQS

0.45

0.5

0.5

ns

23, 27

DQ and DM input pulse width (for each input)

1.75

1.75

1.75

ns

27

Access window of DQS from CK/CK#

-0.60

+0.60

-0.75

+0.75

-0.75

+0.75

ns

DQS input high pulse width

0.35

0.35

0.35

DQS input low pulse width

0.35

0.35

0.35

DQS-DQ skew, DQS to last DQ valid, per group, per access

0.4

0.5

0.5

ns

22, 23

Write command to first DQS latching transition

0.75

1.25

0.75

1.25

0.75

1.25

DQS falling edge to CK rising - setup time

0.20

0.20

0.20

DQS falling edge from CK rising - hold time

0.20

0.20

0.20

Half clock period

ns

8

Data-out high-impedance window from CK/CK#

+0.70

+0.75

+0.75

ns

16, 36

Data-out low-impedance window from CK/CK#

-0.70

-0.75

-0.75

ns

16, 36

Address and control input hold time (fast slew rate)

0.75

0.90

0.90

ns

12

Address and control input setup time (fast slew rate)

0.75

0.90

.900

ns

12

Address and control input hold time (slow slew rate)

0.8

1

1

ns

12

Address and control input setup time (slow slew rate)

0.8

1

1

ns

12

Address and Control input pulse width (for each input)

2.2

2.2

2.2

ns

LOAD MODE REGISTER command cycle time

12

15

15

ns