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112099

FEATURES

Requires no external components

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

in 1°C increments. Fahrenheit equivalent is -

Converts temperature to digital word in 1

second (max.)

Thermostatic settings are user definable and

nonvolatile

Available in 3-pin PR35, TO-220, and 8-pin

SOIC packages

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 +5V

NC

- No Connect

DNC

- Do Not Connect

DESCRIPTION

The DS1821 Programmable Digital Thermostat provides a thermal alarm logic output when the

temperature of the device exceeds a user-defined temperature TH. The output remains active until the

temperature drops below user defined temperature TL, allowing for any hysteresis necessary.

User-defined temperature settings are stored in nonvolatile memory, so parts can be programmed prior to

insertion in a system. Communication to/from the DS1821 is accomplished through the DQ pin in a

programming mode; this same pin is used in operation as the thermostat output.

DS1821

Programmable Digital Thermostat

www.dalsemi.com

6

3

1

2

4

8

7

5

DQ

GND

NC

DNC

NC

NC

DNC

DS1821S 8-Pin SOIC (208-mil)

See Mech Drawings Section

DS1821

PR35 PACKAGE

See Mech. Drawing

Section

DS1821T

TO-220 PACKAGE

See Mech. Drawing

Section