www.maxim-ic.com
DS1244/DS1244P
256k NV SRAM
with Phantom Clock
PIN ASSIGNMENT (Top View)
A14/RST
A12
A7
A6
A5
A4
A3
A2
A1
A0
DQ0
DQ1
DQ2
GND
1
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
V
CC
WE
A13
A8
A9
A11
OE
A10
CE
DQ7
DQ6
DQ5
DQ4
DQ3
www.maxim-ic.com
FEATURES
§
§
§
§
§
§
§
§
§
§
§
§
Real-time clock (RTC) keeps track of
hundredths of seconds, minutes, hours, days,
date of the month, months, and years
32k x 8 NV SRAM directly replaces volatile
static RAM or EEPROM
Embedded lithium energy cell maintains
calendar operation and retains RAM data
Watch function is transparent to RAM
operation
Month and year determine the number of
days in each month; valid up to 2100
Full 10% operating range
Operating temperature range: 0°C to +70°C
Over 10 years of data retention in the
absence of power
Lithium energy source is electrically
disconnected to retain freshness until power
is applied for the first time
DIP module only
Standard 28-pin JEDEC pinout
PowerCap
®
module board only
– Surface mountable package for direct
connection to PowerCap containing
battery and crystal
– Replaceable battery (PowerCap)
– Pin-for-pin compatible with DS1248P
and DS1251P
Underwriters Laboratory (UL) recognized
RST
N.C.
N.C.
N.C.
V
CC
WE
OE
CE
DQ7
DQ6
DQ5
DQ4
DQ3
DQ2
DQ1
DQ0
GND
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
X1
GND V
BAT
X2
34
33
32
31
30
29
28
27
26
25
24
23
22
21
20
19
18
N.C.
N.C.
A14
A13
A12
A11
A10
A9
A8
A7
A6
A5
A4
A3
A2
A1
A0
§
(Uses DS9034PCX PowerCap)
Package Dimension Information
PowerCap is a registered trademark of Dallas Semiconductor.
Note:
Some revisions of this device may incorporate deviations from published specifications known as errata. Multiple revisions of any device
may be simultaneously available through various sales channels. For information about device errata, click here:
1 of 19
081902
DALLAS [ DALLAS SEMICONDUCTOR ]
