DS12C887 Datasheet, PDF (14/19 Pages) Dallas Semiconductor – Real Time Clock

AC ELECTRICAL CHARACTERISTICS
DS12C887
(0°C to 70°C; VCC = 5.0V ± 10%)
PARAMETER
Cycle Time
Pulse Width, DS/E Low or
RD/ WR High
Pulse Width, DS/E High or
RD/ WR Low
Input Rise and Fall
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
Mux’ed Address Valid Time to
ALE Fall
Mused Address Hold Time to
ALE Fall
Delay Time DS/E to AS/ALE
Rise
Pulse Width AS/ALE High
Delay Time, AS/ALE to DS/E
Rise
Output Data Delay Time from
DS/E or RD
Data Setup Time
Reset Pulse Width
IRQ Release from DS
IRQ Release from RESET
SYMBOL
t_CYC
PW_EL
PW_RH
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
MIN
385
150
125
10
50
20
0
10
0
30
10
20
60
40
20
100
5
TYP
MAX
DC
UNITS
ns
ns
NOTES
ns
30
ns
ns
ns
ns
ns
80
ns
ns
ns
ns
ns
ns
ns
120
ns
6
ns
µs
2
µs
2
µs
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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