Real-Time Clocks
DC ELECTRICAL CHARACTERISTICS
(V
CC
= 0V, V
BAT
= 3.0V,
T
A
= over the operating range, unless otherwise noted.) (Note 2)
PARAMETER
V
BAT
Current (OSC On);
T
A
= +25°C, V
BACKUP
= 3.0V
V
BAT
Current (Oscillator Off)
SYMBOL
I
BAT
I
BATDR
(Note 8)
(Note 8)
CONDITIONS
MIN
TYP
MAX
500
100
UNITS
nA
nA
DS12885/DS12887/DS12887A/DS12C887/DS12C887A
AC ELECTRICAL CHARACTERISTICS
(V
CC
= 4.5V to 5.5V,
T
A
= over the operating range.) (Note 2)
PARAMETER
Cycle Time
Pulse Width, DS Low or R/W High
Pulse Width, DS High or R/W Low
Input Rise and Fall
R/W Hold Time
R/W Setup Time Before DS/E
Chip-Select Setup Time Before
DS or R/W
Chip-Select Hold Time
Read-Data Hold Time
Write-Data Hold Time
Address Valid Time to AS Fall
Address Hold Time to AS Fall
Delay Time DS/E to AS Rise
Pulse Width AS High
Delay Time, AS to DS/E Rise
Output Data Delay Time from DS
or R/W
Data Setup Time
Reset Pulse Width
IRQ
Release from DS
IRQ
Release from
RESET
SYMBOL
t
CYC
PW
EL
PW
EH
t
R
, t
F
t
RWH
t
RWS
t
CS
t
CH
t
DHR
t
DHW
t
ASL
t
AHL
t
ASD
PW
ASH
t
ASED
t
DDR
t
DSW
t
RWL
t
IRDS
t
IRR
10
50
20
0
10
0
30
10
20
60
40
20
100
5
2
2
120
80
CONDITIONS
MIN
385
150
125
30
TYP
MAX
DC
UNITS
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
µs
µs
µs
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3