WEDPN16M64V-XB2X
PRELIMINARY
AC FUNCTIONAL CHARACTERISTICS
(NOTES 5,6,7,8,9,11)
Parameter/Condition
Symbol
tCCD
tCKED
tPED
-100
1
-125
1
-133
1
Units
tCK
tCK
tCK
tCK
tCK
tCK
tCK
tCK
tCK
tCK
tCK
tCK
tCK
tCK
tCK
READ/WRITE command to READ/WRITE command (17)
CKE to clock disable or power-down entry mode (14)
CKE to clock enable or power-down exit setup mode (14)
DQM to input data delay (17)
1
1
1
1
1
1
tDQD
tDQM
tDQZ
tDWD
tDAL
0
0
0
DQM to data mask during WRITEs (17)
DQM to data high-impedance during READs (17)
WRITE command to input data delay (17)
Data-in to ACTIVE command (15)
0
0
0
2
2
2
0
0
0
4
5
6
Data-in to PRECHARGE command (16)
Last data-in to burst STOP command (17)
Last data-in to new READ/WRITE command (17)
Last data-in to PRECHARGE command (16)
tDPL
2
2
2
tBDL
1
1
1
tCDL
1
1
1
tRDL
2
2
2
LOAD MODE REGISTER command to ACTIVE or REFRESH command (24 )
tMRD
tROH
tROH
2
2
2
CL = 3
CL = 2
3
3
3
Data-out to high-impedance from PRECHARGE command (17)
NOTES
2
—
—
1. All voltages referenced to VSS
2. This parameter is not tested but garanteed by design. f = 1 MHz, TA = 25°C.
3. DD is dependent on output loading and cycle rates. Specified values are obtained with minimum
cycle time and the outputs open.
.
13. ICC specifications are tested after the device is properly initialized.
14. Timing actually specified by tCKS; clock(s) specified as a reference only at minimum cycle rate.
15. Timing actually specified by tWR plus tRP; clock(s) specified as a reference only at minimum cycle
I
rate.
4. Enables on-chip refresh and address counters.
16. Timing actually specified by tWR.
5. The minimum specifications are used only to indicate cycle time at which proper operation over
the full temperature range is ensured.
17. Required clocks are specified by JEDEC functionality and are not dependent on any timing
parameter.
6. An initial pause of 100μs is required after power-up, followed by two AUTO REFRESH
commands, before proper device operation is ensured. (VCC must be powered up
simultaneously.) The two AUTO REFRESH command wake-ups should be repeated any time
the tREF refresh requirement is exceeded.
18. The ICC current will decrease as the CAS latency is reduced. This is due to the fact that the
maximum cycle rate is slower as the CAS latency is reduced.
19. Address transitions average one transition every two clocks.
20. CLK must be toggled a minimum of two times during this period.
7. AC characteristics assume tT = 1ns.
21.
V
IH overshoot: VIH (MAX) = VCC + 2V for a pulse width 3ns, and the pulse width cannot be
8. In addition to meeting the transition rate specification, the clock and CKE must transit between
greater than one third of the cycle rate. VIL undershoot: VIL (MIN) = -2V for a pulse width 3ns.
V
IH and VIL (or between VIL and VIH) in a monotonic manner.
22. The clock frequency must remain constant (stable clock is defined as a signal cycling within
timing constraints specified for the clock pin) during access or precharge states (READ, WRITE,
including tWR, and PRECHARGE commands). CKE may be used to reduce the data rate.
23. Auto precharge mode only.
9. Outputs measured at 1.5V with equivalent load:
50Ω
Q
1.5V
24. Precharge mode only.
10. tHZ defines the time at which the output achieves the open circuit condition; it is not a reference
to VOH or VOL. The last valid data element will meet tOH before going High-Z.
11. AC timing and IDD tests have VIL = 0V and VIH = 3V, with timing referenced to 1.5V crossover
point.
25. JEDEC and PC100 specify three clocks.
26. Parameter guaranteed by design.
27. Self refresh avaiable in commercial and industrial temperatures only.
28. tAC for 100MHz at CL = 3 with no load is 4.6ns and is guaranteed by design.
12. Other input signals are allowed to transition no more than once every two clocks and are
otherwise at valid VIH or VIL levels.
29. Parameter guaranteed by design.
30. For operating frequencies ≤ 45 MHz tCKS = 3.0ns.
Microsemi Corporation reserves the right to change products or specifications without notice.
July 2011 © 2011 Microsemi Corporation. All rights reserved.
Rev. 1
10
Microsemi Corporation • (602) 437-1520 • www.microsemi.com/pmgp
MERCURY [ MERCURY UNITED ELECTRONICS INC ]
