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102299

FEATURES

§ Temperature measurements require no

external components

§ Measures temperatures from –55°C to

+125°C in 0.5°C increments. Fahrenheit

equivalent is –67°F to 257°F in 0.9°F

increments

§ Temperature is read as a 9–bit value (2-

byte transfer)

§ Wide power supply range (2.7V to 5.5V)

§ Converts temperature to digital word in 1

second

§ Thermostatic settings are user definable

and nonvolatile

§ Data is read from/written via a two–wire

serial interface (open drain I/O lines)

§ Applications include thermostatic

controls, industrial systems, consumer

products, thermometers, or any thermal

sensitive system

§ 8–pin DIP or SOIC package (150-MIL and

208-MIL)

PIN ASSIGNMENT

PIN DESCRIPTION

SDA

- 2-Wire Serial Data Input/Output

SCL

- 2-Wire Serial Clock

GND

- Ground

- Thermostat Output Signal

A0

- Chip Address Input

A1

- Chip Address Input

A2

- Chip Address Input

- Power Supply Voltage

DESCRIPTION

The DS1621 Digital Thermometer and Thermostat provides 9–bit temperature readings which indicate

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 may be programmed prior to

insertion in a system. Temperature settings and temperature readings are all communicated to/from the

DS1621 over a simple two–wire serial interface.

DS1621

Digital Thermometer and Thermostat

www.dalsemi.com

6

3

1

2

4

8

7

5

SDA

GND

DS1621S 8-PIN SOIC (150-MIL)

DS1621V 8-PIN SOIC (208-MIL)

See Mech Drawings Section

6

3

1

2

4

8

7

5

SDA

SCL

GND

DS1621 8-PIN DIP (300-MIL)

See Mech Drawings Section

SCL