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REV: 031704

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.

GENERAL DESCRIPTION

The DS1501/DS1511 are full-function, year 2000-

compliant real-time clock/calendars (RTCs) with an

RTC alarm, watchdog timer, power-on reset, battery

monitors, 256 bytes NV SRAM, and a 32.768kHz

output. User access to all registers within the

DS1501/DS1511 is accomplished with a byte-wide

interface, as shown in Figure 8. The RTC registers

contain century, year, month, date, day, hours,

minutes, and seconds data in 24-hour binary-coded

decimal (BCD) format. Corrections for day of month

and leap year are made automatically.

APPLICATIONS

Remote Systems

Battery-Backed Systems

Telecom Switches

Office Equipment

Consumer Electronics

ORDERING INFORMATION

PART

TEMP RANGE

PIN-PACKAGE

DS1501YN

-40°C to +85°C

28 DIP (600 mil)

DS1501YEN

-40°C to +85°C

28 TSOP

DS1501YSN

-40°C to +85°C

28 SO (330 mil)

DS1501WN

-40°C to +85°C

28 DIP (600 mil)

DS1501WEN

-40°C to +85°C

28 TSOP

DS1501WSN

-40°C to +85°C

28 SO (330 mil)

DS1511Y

0°C to +70°C

28 Module (720 mil)

DS1511W

0°C to +70°C

28 Module (720 mil)

Selector Guide appears at end of data sheet.

Typical Operating Circuits appears at end of data sheet.

FEATURES

§

BCD-Coded Century, Year, Month, Date, Day,

Hours, Minutes, and Seconds with Automatic

Leap-Year Compensation Valid Up to the Year

2100

§

Programmable Watchdog Timer and RTC Alarm

§

Century Register; Y2K-Compliant RTC

§

+3.3 or +5V Operation

§

Precision Power-On Reset

§

Power-Control Circuitry Support System Power-

On from Date/Day/Time Alarm or Key

Closure/Modem-Detect Signal

§

256 Bytes Battery-Backed NV SRAM

§

Auxiliary Battery Input

§

Accuracy of DS1511 Better than ±1

Minute/Month at +25°C

§

Day-of-Week/Date Alarm Register

§

Crystal Select Bit Allow RTC to Operate with 6pF

or 12.6pF Crystal

§

Battery Voltage-Level Indicator Flags

§

Available as Chip (DS1501) or Stand-Alone

Module with Embedded Battery and Crystal

(DS1511)

§

UL Recognized

PIN CONFIGURATION

DS1501/DS1511

Y2K-Compliant Watchdog

Real-Time Clocks

www.maxim-ic.com

TOP VIEW

Dallas

Semiconductor

DS1501

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

SQW

GND

DQ7

DQ6

DQ5

DQ4

DQ3

WE

KS

OE

CE

X1

X2

A4

A3

A2

A1

A0

DQ0

DQ1

DQ2

GND

PWR

RST

IRQ

DIP, SO

Pin Configurations are continued at end of data sheet.