DS12C887
AC ELECTRICAL CHARACTERISTICS
(0°C to 70°C; VCC = 5.0V ± 10%)
PARAMETER
SYMBOL
MIN
TYP
MAX
UNITS NOTES
Cycle Time
Pulse Width, DS/E Low or
RD/ WR High
tCYC
PWEL
385
150
DC
ns
ns
Pulse Width, DS/E High or
RD/ WR Low
Input Rise and Fall
PWRH
125
ns
tR, tF
tRWH
tRWS
tCS
30
80
ns
ns
ns
ns
10
50
20
R/W Hold Time
R/W Setup Time Before DS/E
Chip Select Setup Time Before
DS, WR , or RD
Chip Select Hold Time
Read Data Hold Time
Write Data Hold Time
tCH
tDHR
tDHW
tASL
0
10
0
ns
ns
ns
ns
Mux’ed Address Valid Time to
30
ALE Fall
Mused Address Hold Time to
ALE Fall
tAHL
tASD
10
20
ns
ns
Delay Time DS/E to AS/ALE
Rise
Pulse Width AS/ALE High
PWASH
tASED
60
40
ns
ns
Delay Time, AS/ALE to DS/E
Rise
Output Data Delay Time from
DS/E or RD
tDDR
20
120
ns
6
Data Setup Time
Reset Pulse Width
tDSW
tRWL
tIRDS
100
5
ns
µs
µs
2
2
IRQ Release from DS
tIRR
µs
IRQ Release from RESET
NOTES:
1. All voltages are referenced to ground.
2. All Outputs are open.
3. The MOT pin has an internal pull-down of 20KΩ.
4. Applies to the AD0-AD7 pins, the IRQ pin, and the SQW pin when each is in a high impedance state.
5. The IRQ pin is open drain.
6. Measured with a load as shown in Figure 4.
7. Real-Time Clock Modules can be successfully processed through conventional wave-soldering
techniques as long as temperature exposure to the lithium energy source contained within does not
exceed +85°C. Post solder cleaning with water washing techniques is acceptable, provided that
ultrasonic vibration is not used. Such cleaning can damage the crystal.
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DALLAS [ DALLAS SEMICONDUCTOR ]
