Rtc ac timing characteristics, Ac test conditions – Rainbow Electronics DS1687 User Manual
Page 31
DS1685/DS1687
31 of 38
RTC AC TIMING CHARACTERISTICS
(V
CC
= 5.0V±10%, 0°C to +70°C, -40°C to 85°C)
PARAMETER
SYMBOL
MIN
TYP
MAX
UNITS
NOTES
Cycle Time
t
CYC
195
DC
ns
Pulse Width,
RD
/
WR
Low
PW
RWL
75
ns
Pulse Width,
RD
/
WR
High
PW
RWH
75
ns
Input Rise and Fall Time
t
R
, t
F
30
ns
Chip-Select Setup Time
Before
WR
, or
RD
t
CS
20
ns
Chip-Select Hold Time
t
CH
0
ns
Read-Data Hold Time
t
DHR
10
50
ns
Write-Data Hold Time
t
DHW
0
ns
Muxed Address Valid Time
to ALE Fall
t
ASL
30
ns
Muxed Address Hold Time
from ALE Fall
t
AHL
15
ns
RD
or
WR
High Setup to
ALE Rise
t
ASD
25
ns
Pulse-Width ALE High
PW
ASH
40
ns
ALE Low Setup to
RD
or
WR
Fall
t
ASED
30
ns
Output-Data Delay Time
from
RD
t
DDR
20
60
ns
7
Data Setup Time
t
DSW
60
ns
IRQ
Release from
RD
t
IRD
2
ms
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