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DS1248 Datasheet, PDF (10/21 Pages) Dallas Semiconductor – 1024k NV SRAM with Phantom Clock
DS1248/DS1248P
PHANTOM CLOCK AC ELECTRICAL CHARACTERISTICS
Over the operating range (5V)
PARAMETER
SYMBOL MIN TYP MAX UNITS NOTES
Read Cycle Time
CE Access Time
tRC
65
tCO
ns
55
ns
OE Access Time
tOE
55
ns
CE to Output Low-Z
tCOE
5
ns
OE to Output Low-Z
tOEE
5
ns
CE to Output High-Z
tOD
25
ns
5
OE to Output High-Z
tODO
25
ns
5
Read Recovery
Write Cycle Time
Write Pulse Width
Write Recovery
Data Setup Time
Data Hold Time
CE Pulse Width
tRR
10
tWC
65
tWP
55
tWR
10
tDS
30
tDH
0
tCW
60
ns
ns
ns
3
ns
10
ns
4
ns
4
ns
RESET Pulse Width
tRST
65
ns
POWER-DOWN/POWER-UP TIMING
PARAMETER
SYMBOL
CE at VIH before Power-Down
tPD
VCC Slew from VPF(max) to
tF
VPF(min)( CE at VPF)
VCC Slew from VPF(min) to VSO
tFB
VCC Slew from VPF(max) to
tR
VPF(min)( CE at VPF)
CE at VIH after Power-Up
tREC
Over the operating range (3.3V)
MIN TYP MAX UNITS NOTES
0
ms
300
ms
10
ms
0
ms
1.5
2.5
ms
PARAMETER
Expected Data Retention Time
SYMBOL
tDR
MIN
10
(TA = +25°C)
TYP MAX UNITS NOTES
years
9
Warning: Under no circumstances are negative undershoots of any amplitude allowed when device is in
battery-backup mode.
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