DS14285 Datasheet, PDF (21/25 Pages) Dallas Semiconductor – Real Time Clock with NV RAM Control

POWER-DOWN/POWER-UP TIMING
DS14285/DS14287
POWER-DOWN/POWER-UP TIMING
PARAMETER
SYMBOL
CS at V_IH before Power-Down
t_PD
V_CC slew from 4.5V to 0V ( CS at V_IH)
t_F
V_CC slew from 0V to 4.5V ( CS at V_IH)
t_R
CS at V_IH after Power-Up
t_REC
Chip Enable Propagation Delay to
t_CED
External SRAM
MIN
0
300
100
20
TYP
MAX
200
10
UNITS
µs
µs
µs
ms
ns
NOTES
(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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