Datasheet

DS1251/DS1251P
13 of 20
POWER-DOWN/POWER-UP TIMING
(T
A
= Over the operating range.) (3.3V)
17BPARAMETER SYMBOL MIN TYP MAX UNITS NOTES
CE at V
IH
before Power-Down t
PD
0
µs
V
CC
Slew from V
PF(MAX)
to
V
PF(MIN)
(CE at V
IH
)
t
F
300
µs
V
CC
Slew from V
PF(MAX)
to
V
PF(MIN)
(CE at V
IH
)
t
R
0
µs
CE at V
IH
after Power-Up t
REC
1.5 2.5 ms
(T
A
= +25°C)
5BPARAMETER SYMBOL MIN TYP MAX UNITS NOTES
Expected Data Retention Time
t
DR
10
years
9
Warning:
Under no circumstances are negative undershoots of any amplitude allowed when device
is in battery-backup mode.