DS17285 Datasheet, PDF (28/38 Pages) Dallas Semiconductor – 3V/5V Real-Time Clock

RTC AC TIMING CHARACTERISTICS
PARAMETER
Cycle Time
Pulse-Width, RD / WR Low
SYMBOL
t_CYC
PW_RWL
MIN
240
120
Pulse-Width, RD / WR High
PW_RWH
80
Input Rise and Fall Time
t_R, t_F
Chip-Select Setup Time
before WR or RD
t_CS
20
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
ALE Fall
t_ASL
20
Muxed Address Hold Time to
ALE fall
t_AHL
10
RD or WR High Setup to
ALE Rise
Pulse-Width ALE High
t_ASD
25
PW_ASH
40
ALE Low Setup to RD or WR
Fall
t_ASED
30
Output Data-Delay Time from
t_DDR
20
RD
Data Setup Time
t_DSW
30
IRQ Release from RD
t_IRD
AC TEST CONDITIONS
Output Load: 50pF
Input Pulse Levels: 0V to 3.0V
Timing Measurement Reference Levels
Input: 1.5V
Output: 1.5V
Input Pulse Rise and Fall Times: 5ns
DS17285/DS17287
Over the operating range (5V)
TYP
MAX
DC
UNITS NOTES
ns
ns
ns
30
ns
ns
ns
50
ns
ns
ns
ns
ns
ns
ns
120
ns
6
ns
2
ms
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