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080299

FEATURES

§ Real time clock keeps track of hundredths of

seconds, seconds, minutes, hours, days, date

of the month, months, and years

§ 8K 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

§ Lithium

energy

source

is

electrically

disconnected to retain freshness until power is

applied for the first time

§ Standard 28–pin JEDEC pinout

§ Full ±10% operating range

§ Operating temperature range 0°C to 70°C

§ Accuracy is better than ±1 minute/month @

25°C

§ Over 10 years of data retention in the absence

of power

§ Available in 120, 150 and 200 ns access time

ORDERING INFORMATION

DS1243Y–XXX

–120

120 ns access

–150

150 ns access

DS1243Y

200 ns access

PIN ASSIGNMENT

PIN DESCRIPTION

– Address Inputs

CE

– Chip Enable

GND

– Ground

– Data In/Data Out

– Power (+5V)

WE

– Write Enable

OE

– Output Enable

NC

– No Connect

RST

– Reset

DESCRIPTION

The DS1243Y 64K NV SRAM with Phantom Clock is a fully static nonvolatile RAM (organized as 8192

words by 8 bits) with a built–in real time clock. The DS1243Y has a self–contained lithium energy source

condition occurs, the lithium energy source is automatically switched on and write protection is

unconditionally enabled to prevent corrupted data in both the memory and real time clock.

DS1243Y

64K NV SRAM with Phantom Clock

www.dalsemi.com

28-Pin Encapsulated Package

720-Mil Extended

A7

A5

A3

A2

A1

A0

DQ0

DQ1

GND

DQ2

WE

NC

A8

A9

A11

OE

A10

CE

DQ7

DQ6

DQ5

DQ3

DQ4

1

2

3

4

5

6

7

8

9

10

11

12

14

13

28

27

26

25

24

23

22

21

20

19

18

17

15

16

A12

A6

A4

RST