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FEATURES



Integrates 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.



Totally Nonvolatile with Over 10 Years of

Operation in the Absence of Power



BCD Coded Year, Month, Date, Day, Hours,

Minutes, and Seconds with Leap Year

Compensation Valid Through 2099



Power-Fail Write Protection Allows for



DS1647 Only (DIP Module):

Standard JEDEC Byte-Wide 128k x 8 RAM

Pinout



DS1647P Only (PowerCap Module Board):

Surface Mountable Package for Direct

Connection to PowerCap Containing

Battery and Crystal

Replaceable Battery (PowerCap)

Power-Fail Output

Pin-for-Pin Compatible with Other Densities

of DS164XP Timekeeping RAM

PIN CONFIGURATIONS

ORDERING INFORMATION

PART

TEMP

RANGE

PIN-

PACKAGE

TOP

MARK**

DS1647-120+

0°C to

+70°C

32 EDIP

(0.740a)

DS1647+120

DS1647P-120+

0°C to

+70°C

34

PowerCap*

DS1647P+120

+Denotes a lead(Pb)-free/RoHS-compliant package.

*DS9034PCX+ or DS9034I-PCX+ required (must be ordered separately).

**A “+” indicates lead(Pb)-free. The top mark includes a “+” symbol on lead(Pb)-free devices.

DS1647/DS1647P

Nonvolatile Timekeeping RAM

www.maxim-ic.com

13

1

2

3

4

5

6

7

8

9

10

11

12

14

31

32-Pin Encapsulated DIP Package

(32 Pin 740)

A14

A7

A5

A4

A3

A2

A1

A0

DQ1

DQ0

A15

A17

WE

A13

A8

A9

A11

OE

A10

CE

DQ7

DQ5

DQ6

32

30

29

28

27

26

25

24

23

22

21

19

20

A16

A12

A6

A18

DQ2

GND

15

16

18

17

DQ4

DQ3

1

N.C.

2

3

A15

A16

PFO

WE

OE

CE

DQ7

DQ6

DQ5

DQ4

DQ3

DQ2

DQ1

DQ0

GND

4

5

6

7

8

9

10

11

12

13

14

15

16

17

A17

A14

33

32

31

30

29

28

27

26

25

24

23

22

21

20

19

18

A13

A12

A11

A10

A9

A8

A7

A6

A5

A4

A3

A2

A1

A0

34

A18

34-Pin PowerCap Module Board

(Uses DS9034PCX+ or DS9034I-PCX+ PowerCap)

TOP VIEW

DS1647

DS1647P

19-5596; Rev 10/10