BENEFITS AND FEATURES



Simply Adds Temperature Monitoring and

Control to Any System

o Measures Temperatures From -55°C to

+125°C in 0.5°C Increments. Fahrenheit

Equivalent is -67°F to 257°F in 0.9°F

Increments

o Temperature is Read as a 9-Bit Value (2-

Byte Transfer)

o Converts Temperature to Digital Word in

Less than 1s

o Thermostatic Settings are User Definable

And Nonvolatile



Can Be Used in a Wide Variety of

Applications

o Power Supply Range (2.7V to 5.5V)

o Data is Read From/Written Via a 2-Wire

Serial Interface (Open Drain I/O Lines)



Saves Space

o Temperature Measurements Require No

External Components

o 8-pin DIP or SO package (208-mil)

Packages

APPLICATIONS

⋅

Thermostatic Controls

⋅

Industrial Systems

⋅

Consumer Products

⋅

Thermometers

PIN ASSIGNMENT

PIN DESCRIPTION

SDA

- 2-Wire Serial Data Input/Output

SCL

- 2-Wire Serial Clock

GND

- Ground

- Thermostat Output Signal

A0

- Chip Address Input

A1

- Chip Address Input

A2

- Chip Address Input

- Power Supply Voltage

DESCRIPTION

The DS1621 Digital Thermometer and Thermostat provides 9-bit temperature readings, which indicate

device exceeds a user-defined temperature TH. The output remains active until the temperature drops

below user defined temperature TL, allowing for any hysteresis necessary.

User-defined temperature settings are stored in nonvolatile memory so parts may be programmed prior to

insertion in a system. Temperature settings and temperature readings are all communicated to/from the

DS1621 over a simple 2-wire serial interface.

DS1621

Digital Thermometer and

6

3

1

2

4

8

7

5

SDA

GND

DS1621S 8-PIN SO (150mil)

DS1621V 8-PIN SO (208mil)

6

3

1

2

4

8

7

5

SDA

SCL

GND

DS1621 8-PIN DIP (300mil)

SCL

1 of 16

19-7540; Rev 4; 3/15