DS1685/DS1687 3V/5V Real-Time Clocks
RTC AC TIMING CHARACTERISTICS
(VCC = 3.0V±10%, TA = 0°C to +70°C, TA = -40°C to +85°C)
PARAMETER
Cycle Time
SYMBOL
tCYC
MIN
260
100
100
TYP
MAX
UNITS
ns
NOTES
DC
PWRWL
PWRWH
tR, tF
ns
Pulse Width, RD/WR Low
Pulse Width, RD/WR High
Input Rise and Fall Time
ns
30
50
ns
Chip-Select Setup Time
tCS
20
ns
Before WR or RD
Chip-Select Hold Time
Read-Data Hold Time
Write-Data Hold Time
tCH
tDHR
tDHW
0
10
0
ns
ns
ns
Muxed Address Valid Time to
ALE Fall
tASL
tAHL
30
15
ns
ns
Muxed Address Hold Time
from ALE Fall
RD or WR High Setup to ALE
tASD
PWASH
tASED
30
80
30
ns
ns
ns
Rise
Pulse-Width ALE High
ALE Low Setup to RD or WR
Fall
Output-Data Delay Time from
tDDR
20
60
80
2
ns
6
RD
Data Setup Time
tDSW
tIRD
ns
IRQ Release from RD
µs
AC TEST CONDITIONS
Output Load: 50pF
Input Pulse Levels: 0 to 3.0V
Timing Measurement Reference Levels
Input : 1.5V
Output: 1.5V
Input Pulse Rise and Fall Times: 5ns
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DALLAS [ DALLAS SEMICONDUCTOR ]
