Rainbow Electronics DS12C887 - Manual (Page 14)

DS12C887
14 of 19
AC ELECTRICAL CHARACTERISTICS (0°C to 70°C; VCC = 5.0V ± 10%)
PARAMETER SYMBOL MIN TYP MAX UNITS NOTES
Cycle Time t
CYC
385 DC ns
Pulse Width, DS/E Low or
RD/
WR High
PW
EL
150 ns
Pulse Width, DS/E High or
RD/
WR Low
PW
RH
125 ns
Input Rise and Fall t
R
, t
F
30 ns
R/W Hold Time
t
RWH
10 ns
R/W Setup Time Before DS/E
t
RWS
50 ns
Chip Select Setup Time Before
DS,
WR , or RD
t
CS
20 ns
Chip Select Hold Time t
CH
0 ns
Read Data Hold Time t
DHR
10 80 ns
Write Data Hold Time t
DHW
0 ns
Mux’ed Address Valid Time to
ALE Fall t
ASL
30 ns
Mused Address Hold Time to
ALE Fall t
AHL
10 ns
Delay Time DS/E to AS/ALE
Rise t
ASD
20 ns
Pulse Width AS/ALE High PW
ASH
60 ns
Delay Time, AS/ALE to DS/E
Rise t
ASED
40 ns
Output Data Delay Time from
DS/E or
RD
t
DDR
20 120 ns 6
Data Setup Time t
DSW
100 ns
Reset Pulse Width t
RWL
5 µ s
IRQ Release from DS
t
IRDS
2 µ s
IRQ Release from RESET
t
IRR
2 µ s
NOTES:
1. All voltages are referenced to ground.
2. All Outputs are open.
3. The MOT pin has an internal pull-down of 20K
Ω .
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.