DS12C887
POWER DOWN / POWER UP TIMING
PARAMETER
SYMBOL
MIN
TYP
MAX
UNITS NOTES
tPD
0
µs
CS at VIH before Power-
Down
VCC slew from 4.5V to 0V
(CS at VIH)
VCC slew from 0V to 4.5V
(CS at VIH)
tF
300
100
µs
4.0≤ VCC ≤ 4.5V
tR
µs
tREC
tDR
20
10
200
ms
CS at VIH after Power-Up
Expected Data Retention
years
10,11
(tA=25°C)
PARAMETER
SYMBOL
MIN
TYP
MAX
UNITS NOTES
Expected Data Retention
tDR
10
years
10,11
Note:
The real time clock will keep time to an accuracy of ±1 minute per month during data retention time for
the period of tDR.
Warning:
Under no circumstances are negative undershoots, of any amplitude, allowed when device is in battery
back-up mode.
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DALLAS [ DALLAS SEMICONDUCTOR ]
