DS12B887 Datasheet, PDF (12/16 Pages) Dallas Semiconductor – Real Time Clock

DS12B887
AC ELECTRICAL CHARACTERISTICS
PARAMETER
SYMBOL MIN
Cycle Time
t_CYC
385
Pulse Width, DS/E Low or RD/WR PW_EL
150
High
Pulse Width, DS/E High or RD/WR PW_EH
125
Low
Input Rise and Fall Time
t_R,t_F
Chip Select Setup Time Before DS,
t_CS
20
WR, or RD
Chip Select Hold Time
t_CH
0
Read Data Hold Time
t_DHR
10
Write Data Hold Time
t_DHW
0
Muxed Address Valid Time to AS/ t_ASL
30
ALE Fall
Muxed Address Hold Time
t_AHL
10
Delay Time DS/E to AS/ALE Rise
t_ASD
20
Pulse Width AS/ALE High
PW_ASH
60
Delay Time, AS/ALE to DS/E Rise t_ASED
40
Output Data Delay Time From t_DDR
20
DS/E or RD
Data Setup Time
IRQ Release from DS
t_DSW
100
t_IRDS
(0°C to 70°C; V_CC = 4.5V to 5.5V)
TYP
MAX
UNITS NOTES
DC
ns
ns
ns
30
ns
ns
ns
80
ns
ns
ns
ns
ns
ns
ns
120
ns
5
ns
2
ms
NOTES:
1. All voltages are referenced to ground.
2. All outputs are open.
3. Applies to the AD0-AD7 pins, the IRQ pin,and the SQW pin when each is in the high impedance state.
4. The IRQ pin is open drain.
5. Measured with a load of 50 pf + 1 TTL gate.
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