General Description

The DS1374 is a 32-bit binary counter designed to contin-

uously count time in seconds. An additional counter gen-

erates a periodic alarm or serves as a watchdog timer. If

disabled, this counter can be used as 3 bytes of non-

volatile (NV) RAM. Separate output pins are provided for

an interrupt and a square wave at one of four selectable

frequencies. A precision temperature-compensated refer-

detect power failures, provide a reset output, and auto-

matically switch to the backup supply when necessary.

Additionally, the reset pin is monitored as a pushbutton

input for externally generating a reset. The device is pro-

Applications

Portable Instruments

Point-of-Sale Equipment

Medical Equipment

Telecommunications

Features

♦ 32-Bit Binary Counter

♦ Second Binary Counter Provides Time-of-Day

Alarm, Watchdog Timer, or NV RAM

♦ Separate Square-Wave and Interrupt Output Pins

♦ Automatic Power-Fail Detect and Switch Circuitry

♦ Single-Pin Pushbutton Reset Input/Open-Drain

Reset Output

♦ Low-Voltage Operation

♦ Trickle-Charge Capability

♦ -40°C to +85°C Operating Temperature Range

♦ 10-Pin µSOP, 16-Pin SO

♦ Available in a Surface-Mount Package with an

Integrated Crystal (DS1374C)

♦ Underwriters Laboratory (UL) Recognized

Trickle Charger and Reset Input/Output

______________________________________________ Maxim Integrated Products

1

Ordering Information

DS1374

X1

X2

CRYSTAL

SQW

SCL

SDA

INT

RST

INT

RST

GND

N.O.

PUSHBUTTON

RESET

PRIMARY

BATTERY,

RECHARGEABLE

BATTERY, OR

SUPER CAPACITOR

CPU

RPU

RPU

Typical Operating Circuit

Rev 3; 1/06

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at

1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

PART

TEMP RANGE

VOLTAGE (V)

PIN-PACKAGE

TOP MARK**

DS1374C-18

-40°C to +85°C

1.8

16 SO (300 mils)

DS1374C-18

DS1374C-18#

-40°C to +85°C

1.8

16 SO (300 mils)

DS1374C-18

DS1374C-3

-40°C to +85°C

3.0

16 SO (300 mils)

DS1374C-3

DS1374C-3#

-40°C to +85°C

3.0

16 SO (300 mils)

DS1374C-3

DS1374C-33

-40°C to +85°C

3.3

16 SO (300 mils)

DS1374C-33

DS1374C-33#

-40°C to +85°C

3.3

16 SO (300 mils)

DS1374C-33

DS1374C-33/T&R

-40°C to +85°C

3.3

16 SO (300 mils)/Tape and Reel

DS1374C-33

Inc., or one of its sublicensed Associated Companies, conveys

Pin Configurations appear at the end of the data sheet.

#Denotes a RoHS-compliant device that may include lead that is exempt under RoHS requirements. The lead finish is JESD97 category

e3, and is compatible with both lead-based and lead-free soldering processes.

**A "#" anywhere on the top mark denotes a RoHS-compliant package.

Ordering Information continued at end of data sheet.