AVAILABLE

Functional Diagrams

Pin Configurations appear at end of data sheet.

Functional Diagrams continued at end of data sheet.

UCSP is a trademark of Maxim Integrated Products, Inc.

For pricing, delivery, and ordering information, please contact Maxim Direct

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

REV: 042208

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.

FEATURES

 Unique 1-Wire® Interface Requires Only One

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

DS18B20

Programmable Resolution

1-Wire Digital Thermometer

TO-92

(DS18B20)

1

(BOTTOM VIEW)

2

3

MAXIM

18B20

1

2 3

SO (150 mils)

(DS18B20Z)

N.C.

N.C.

N.C.

N.C.

GND

DQ

VDD

N.C.

6

8

7

5

3

1

2

4

N.C.

VDD

N.C.

N.C.

N.C.

GND

N.C.

DQ

6

8

7

5

3

1

2

4

µSOP

(DS18B20U)

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