Programmable Digital Thermostat and Thermometer

The DS1821 can function as a standalone thermostat with user-programmable trip-points or as 8-bit temperature sensor with a 1-Wire® digital interface. The thermostat trip-points are stored in nonvolatile memory, so DS1821 units can be programmed prior to system insertion for true standalone operation. The DS1821 has an operating temperature range of –55°C to +125°C and is accurate to ±1°C over a range of 0°C to +85°C. Communication with the DS1821 is accomplished through the open-drain DQ pin; this pin also serves as the thermostat output.

Applications

* Consumer Products * Industrial Systems * Thermometers * Thermostatic Controls

* Requires no external components

* Unique 1-Wire interface requires only one port pin for communication

* Operates over a -55°C to +125°C (-67°F to +257°F) temperature range

* Functions as a standalone thermostat with user-definable trip-points

* Provides 8-bit (1°C resolution) centigrade temperature measurements

* Accuracy is ±1°C over 0°C to +85°C range

* Converts temperature to a digital word in 1 second (max)

* Available in 3-pin TO92 and 8-pin SO packages

* Applications include thermostatic controls, industrial systems, consumer products, thermometers, or any thermally sensitive system