DESCRIPTION
The DS1621 Digital Thermometer and Thermostat provides 9–bit temperature readings which indicate the temperature of the device. The thermal alarm output, TOUT, is active 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 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.

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)