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050102

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 mSOP,

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

mSOP

(DS18B20U)

1-Wire is a registered trademark of Dallas Semiconductor.