Real-Time Clocks
DS17285/DS17287/DS17485/DS17487/DS17885/DS17887
AC ELECTRICAL CHARACTERISTICS
(V
CC
= +2.7V to +3.7V,
T
A
= Over the operating range, unless otherwise noted.) (Note 2)
PARAMETER
Cycle Time
Pulse Width,
RD
or
WR
Low
Pulse Width,
RD
or
WR
High
Input Rise and Fall
Chip-Select Setup Time Before
RD
or
WR
Chip-Select Hold Time
Read-Data Hold Time
Write-Data Hold Time
Address Setup Time to ALE Fall
Address Hold Time to ALE Fall
RD
or
WR
High Setup to ALE
Rise
Pulse Width ALE High
Delay Time ALE Low to
RD
Low
Output Data Delay Time from
RD
Data Setup Time
IRQ
Release from
RD
SYMBOL
t
CYC
PW
RWL
PW
RWH
t
R
, t
F
t
CS
t
CH
t
DHR
t
DHW
t
ASL
t
AHL
t
ASD
PW
ASH
t
ASED
t
DDR
t
DSW
t
IRD
(Note 8)
20
0
10
0
40
10
30
40
30
20
70
2
200
90
CONDITIONS
MIN
360
200
150
30
TYP
MAX
DC
UNITS
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
µs
Write Timing
t
CYC
AS
t
ASD
RD
t
ASD
WR
PW
RWH
t
CS
CS
t
ASL
AD0–AD7
WRITE
t
AHL
t
DSW
t
DHW
t
ASED
PW
RWL
t
CH
PW
ASH
4
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MAXIM [ MAXIM INTEGRATED PRODUCTS ]
