5 to 5.5v), Power-down/power-up timing, 25°c) – Rainbow Electronics DS1243Y User Manual
Page 8: Warning
DS1243Y
8 of 13
PHANTOM CLOCK AC ELECTRICAL
CHARACTERISTICS (0°C to 70°C; V
CC
= 4.5 to 5.5V)
PARAMETER
SYMBOL
MIN
TYP
MAX
UNITS
NOTES
Read Cycle Time
t
RC
120
ns
CE
Access Time
t
CO
100
ns
OE
Access Time
t
OE
100
ns
CE
to Output Low Z
t
COE
10
ns
OE
to Output Low Z
t
OEE
10
ns
CE
to Output High Z
t
OD
40
ns
5
OE
to Output High Z
t
ODO
40
ns
5
Read Recovery
t
RR
20
ns
Write Cycle Time
t
WC
120
ns
Write Pulse Width
t
WP
100
ns
Write Recovery
t
WR
20
ns
10
Data Setup Time
t
DS
40
ns
11
Data Hold Time
t
DH
10
ns
11
CE
Pulse Width
t
CW
100
ns
RESET
Pulse Width
t
RST
200
ns
CE
High to Power-Fail
t
PF
0
ns
POWER-DOWN/POWER-UP TIMING
PARAMETER
SYMBOL
MIN
TYP
MAX
UNITS
NOTES
CE
at V
IH
before Power-Down
t
PD
0
µ
s
V
CC
Slew from 4.5V to 0V (
CE
at V
IH
)
t
F
300
µ
s
V
CC
Slew from 0V to 4.5V (
CE
at V
IH
)
t
R
0
µ
s
CE
at V
IH
after Power-Up
t
REC
2
ms
(t
A
= 25°C)
PARAMETER
SYMBOL
MIN
TYP
MAX
UNITS
NOTES
Expected Data Retention Time
t
DR
10
years
9
WARNING:
Under no circumstances are negative undershoots, of any amplitude, allowed when device is in battery
backup mode.