Datasheet

DS17285/DS17287/DS17485/DS17487/DS17885/DS17887
Real-Time Clocks
4 _____________________________________________________________________
AC ELECTRICAL CHARACTERISTICS
(V
CC
= +2.7V to +3.7V, T
A
= Over the operating range, unless otherwise noted.) (Note 2)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Cycle Time t
CYC
360 DC ns
Pulse Width, RD or WR Low PW
RWL
200 ns
Pulse Width, RD or WR High PW
RWH
150 ns
Input Rise and Fall t
R
, t
F
30 ns
Chip-Select Setup Time Before
RD or WR
t
CS
20 ns
Chip-Select Hold Time t
CH
0ns
Read-Data Hold Time t
DHR
10 90 ns
Write-Data Hold Time t
DHW
0ns
Address Setup Time to ALE Fall t
ASL
40 ns
Address Hold Time to ALE Fall t
AHL
10 ns
RD or WR High Setup to ALE
Rise
t
ASD
30 ns
Pulse Width ALE High PW
ASH
40 ns
Delay Time ALE Low to RD Low t
ASED
30 ns
Output Data Delay Time from RD t
DDR
(Note 8) 20 200 ns
Data Setup Time t
DSW
70 ns
IRQ Release from RD t
IRD
2µs
Write Timing
PW
ASH
t
ASED
PW
RWH
PW
RWL
t
CS
t
AHL
t
ASL
t
DSW
t
DHW
t
CH
t
ASD
t
ASD
t
CYC
CS
WR
AS
RD
AD0–AD7
WRITE