DS1244 Maxim, DS1244 Datasheet - Page 11

• Manufacturer Part Number: DS1244
• Description: The DS1244 256k NV SRAM with a Phantom clock is a fully static nonvolatile RAM (NV SRAM) (organized as 32k words by 8 bits) with a built-in real-time clock
• Manufacturer: Maxim

PHANTOM CLOCK AC ELECTRICAL CHARACTERISTICS
Read Cycle Time
Read Recovery
Write Cycle Time
Write Pulse Width
Write Recovery
Data Setup Time
Data Hold Time
POWER-DOWN/POWER-UP TIMING
V
V
V
V
V
Expected Data Retention Time
Warning: Under no circumstances are negative undershoots of any amplitude allowed when device
is in battery-backup mode.
CE
OE
CE
OE
CE
OE
CE
RESET
CE
CE
CC
PF(min)
CC
CC
PF(min)
Access Time
Access Time
to Output Low-Z
to Output Low-Z
to Output High-Z
to Output High-Z
Pulse Width
at V
at V
Slew from V
Slew from V
Slew from V
(
(
Pulse Width
IH
IH
CE
CE
P ARAMETER
1 2 B
P ARAMETER
1 3 B
P ARAMETER
5 B
before Power-Down
after Power-Up
at V
at V
PF
PF
PF(max)
PF(min)
PF(max)
)
)
to V
to
to
SO
SYMBOL
SYMBOL
SYMBOL
t
t
t
t
t
t
t
t
t
t
t
t
t
t
ODO
t
t
t
t
t
COE
OEE
REC
RST
WC
WR
CW
WP
t
RC
CO
OE
OD
RR
DH
t
DR
DS
PD
FB
R
F
MIN
MIN
MIN
300
11 of 20
1.5
65
10
65
55
10
30
60
65
10
10
5
5
0
0
0
TYP
TYP
TYP
Over the operating range (5V)
Over the operating range (5V)
MAX
MAX
MAX
2.5
55
55
25
25
UNITS
UNITS
UNITS
years
ms
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
µs
µs
µs
µs
(T
A
= +25°C)
NOTES
NOTES
NOTES
10
5
5
3
4
4
9