VT82885
Real Time Clock
VIA Technologies, Inc.
VCC
4.5V
VBAT
tF
tR
tPD
tREC
CS#
DATA RETENTION
tDR
CURRENT SUPPLIED
FROM EXTERNAL
LITHIUM ENERGY CELL
POWER DOWN/POWER UP TIMING
PARAMETER
SYMBOL
MIN
TYP
MAX
UNITS
µs
NOTES
CS# at V before Power-Down
t
0
IH
PD
V
CC
slew from 4.5V to 0V
t
F
300
µs
(CS# at V )
IH
V
slew from 0V to 4.5V
t
100
20
µs
CC
R
(CS# at V )
IH
CS# at V after Power-Up
t
200
ms
IH
REC
(tA = 25°C)
PARAMETER
SYMBOL
MIN
10
TYP
MAX
UNITS
years
NOTES
Expected Data Retention
t
DR
NOTE
WARNING
The real time clock will keep time to an
accuracy of ±1 minute per month during data
Under no circumstances are negative
undershots, of any amplitude, allowed when
device is in battery backup mode.
retention time for the period of t
.
DR
16