Functional Diagrams

DESCRIPTION

The DS18B20 digital thermometer provides 9-bit

to 12-bit Celsius temperature measurements and

has an alarm function with nonvolatile userprogrammable

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.

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.

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