DS1747 Datasheet, PDF (1/18 Pages) Dallas Semiconductor – Y2K-Compliant, Nonvolatile Timekeeping RAMs

DS1747/DS1747P
Y2K-Compliant, Nonvolatile Timekeeping RAMs
www.maxim-ic.com
FEATURES
§ Integrated NV SRAM, Real-Time Clock
(RTC), 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 (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 512k 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
A18
A16
A14
A12
A7
A6
A5
A4
A3
A2
A1
A0
DQ0
DQ1
DQ2
GND
1
32
2
Dallas
31
3
Semiconductor
DS1747
30
4
29
5
28
6
27
7
26
8
25
9
24
10
23
11
22
12
21
13
20
14
19
15
18
16
17
VCC
A15
A17
WE
A13
A8
A9
A11
OE
A10
CE
DQ7
DQ6
DQ5
DQ4
DQ3
Encapsulated DIP
(512k x 8)
N.C. 1
A15 2
A16 3
Dallas
Semiconductor
34
33
32
A18
A17
A14
RST 4
DS1747P
31
A13
VCC
WE
5
6
30
A12
29
A11
OE
CE
DQ7
7
8
9
DQ6 ¹⁰
28
A10
27
A9
26
A8
25
A7
DQ5 ¹¹
DQ4 ¹²
DQ3 ¹³
24
A6
23
A5
22
A4
DQ2
DQ1
DQ0
GND
14
21
15
20
16
17
X1 GND VBAT X2
19
18
A3
A2
A1
A0
PowerCap Module Board
(Uses DS9034PCX PowerCap)
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: www.maxim-ic.com/errata.
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REV: 011204