DS1744/DS1744P
Y2K-Compliant, Nonvolatile Timekeeping RAMs
www.maxim-ic.com
FEATURES
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Integrated NV SRAM, Real-Time Clock,
Crystal, Power-Fail Control Circuit, and
Lithium Energy Source
Clock Registers are Accessed Identically to
the Static RAM. These Registers are Resident
in the Eight Top RAM Locations.
Century Byte Register (i.e., Y2K Compliant)
Totally Nonvolatile with Over 10 Years of
Operation in the Absence of Power
BCD-Coded Century, Year, Month, Date,
Day, Hours, Minutes, and Seconds with
Automatic Leap-Year Compensation Valid
Up to the Year 2100
Battery Voltage-Level Indicator Flag
Power-Fail Write Protection Allows for ±10%
V
CC
Power-Supply Tolerance
Lithium Energy Source is Electrically
Disconnected to Retain Freshness Until
Power is Applied for the First Time
DIP Module Only
Standard JEDEC Byte-Wide 32k x 8 Static
RAM Pinout
PowerCap
Ò
Module Board Only
Surface-Mountable Package for Direct
Connection to PowerCap Containing
Battery and Crystal
Replaceable Battery (PowerCap)
Power-On Reset Output
Pin-for-Pin Compatible with Other Densities
of DS174xP Timekeeping RAM
Also Available in Industrial Temperature
Range: -40°C to +85°C
PIN CONFIGURATIONS
TOP VIEW
A14
A12
A7
A6
A5
A4
A3
A2
A1
A0
DQ0
DQ1
DQ2
GND
1
Dallas
2
Semiconductor
3
DS1744
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
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PDIP Module
(700-mil Extended)
N.C.
N.C.
N.C.
RST
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
Dallas
Semiconductor
DS1744P
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
PowerCap Module Board
(Uses DS9034PCX PowerCap)
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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:
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REV: 011204