
DS14285/DS14287
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POWER-DOWN/POWER-UP TIMING
POWER-DOWN/POWER-UP TIMING
PARAMETER SYMBOL MIN TYP MAX UNITS NOTES
CS at V
IH
before Power-Down
t
PD
0
µs
V
CC
slew from 4.5V to 0V (CS at V
IH
)
t
F
300
µs
V
CC
slew from 0V to 4.5V (CS at V
IH
)
t
R
100
µs
CS at V
IH
after Power-Up
t
REC
20 200 ms
Chip Enable Propagation Delay to
External SRAM
t
CED
10 ns
(t
A
= 25°C)
PARAMETER SYMBOL MIN TYP MAX UNITS NOTES
Expected Data Retention for DS14287 t
DR
10 years 10
NOTE:
The real-time clock will keep time to an accuracy of+1 minute per month during data retention time for
the period of t
DR
.
WARNING:
Under no circumstances are negative undershoots, of any amplitude, allowed when device is in battery
backup mode.
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