1 of 22

REV: 042208

FEATURES

Unique 1-Wire

Port Pin for Communication

Each Device has a Unique 64-Bit Serial Code

Stored in an On-Board ROM

Multidrop Capability Simplifies Distributed

Temperature-Sensing Applications

Requires No External Components

Can Be Powered from Data Line; Power Supply

Range is 3.0V to 5.5V

Measures Temperatures from -55°C to +125°C

(-67°F to +257°F)

±0.5°C Accuracy from -10°C to +85°C

Thermometer Resolution is User Selectable

from 9 to 12 Bits

Converts Temperature to 12-Bit Digital Word in

750ms (Max)

User-Definable Nonvolatile (NV) Alarm

Settings

Alarm Search Command Identifies and

Addresses Devices Whose Temperature is

Outside Programmed Limits (Temperature

Alarm Condition)

Available in 8-Pin SO (150 mils), 8-Pin

μSOP,

and 3-Pin TO-92 Packages

Software Compatible with the DS1822

Applications Include Thermostatic Controls,

Industrial Systems, Consumer Products,

Thermometers, or Any Thermally Sensitive

System

PIN CONFIGURATIONS

DESCRIPTION

The DS18B20 digital thermometer provides 9-bit to 12-bit Celsius temperature measurements and has an

alarm function with nonvolatile user-programmable upper and lower trigger points. The DS18B20

communicates over a 1-Wire bus that by definition requires only one data line (and ground) for

communication with a central microprocessor. It has an operating temperature range of -55°C to +125°C

and is accurate to

±0.5°C over the range of -10°C to +85°C. In addition, the DS18B20 can derive power

directly from the data line (“parasite power”), eliminating the need for an external power supply.

Each DS18B20 has a unique 64-bit serial code, which allows multiple DS18B20s to function on the same

1-Wire bus. Thus, it is simple to use one microprocessor to control many DS18B20s distributed over a

large area. Applications that can benefit from this feature include HVAC environmental controls,

temperature monitoring systems inside buildings, equipment, or machinery, and process monitoring and

control systems.

DS18B20

Programmable Resolution

1-Wire Digital Thermometer

www.maxim-ic.com

1-Wire is a registered trademark of Maxim Integrated Products, Inc.

TO-92

(DS18B20)

1

(BOTTOM VIEW)

2

3

DALLAS

18B20

1

2 3

SO (150 mils)

(DS18B20Z)

N.C.

N.C.

N.C.

N.C.

GND

DQ

N.C.

6

8

7

5

3

1

2

4

N.C.

N.C.

N.C.

N.C.

GND

N.C.

DQ

6

8

7

5

3

1

2

4

μSOP

(DS18B20U)