1 of 21

101207

FEATURES

Unique 1-Wire

port pin for communication

Each device has a unique 64-bit serial code

stored in an onboard 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 of programmed limits (temperature

alarm condition)

Available in 8-pin SO (150mil), 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 ASSIGNMENT

PIN DESCRIPTION

GND - Ground

DQ

- Data In/Out

- Power Supply Voltage

NC

- No Connect

DESCRIPTION

The DS18B20 Digital Thermometer provides 9 to 12–bit centigrade 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

8-Pin 150mil SO

(DS18B20Z)

TO-92

(DS18B20)

1

(BOTTOM VIEW)

2

3

DALLAS

18B20

1

2 3

NC

NC

NC

NC

GND

DQ

NC

6

8

7

5

3

1

2

4

NC

NC

NC

NC

GND

NC

DQ

6

8

7

5

3

1

2

4

8-Pin

μSOP

(DS18B20U)

1-Wire is a registered trademark of Dallas Semiconductor.