The DS1721 digital thermometer and thermostat features ±1°C accuracy over a -10°C to +85°C range. Thermometer data is read out over a 2-wire serial bus in 2's complement format with 9 to 12 bits of resolution (user-programmable). The DS1721 features three address inputs, allowing users to multidrop up to eight DS1721 devices on one bus.

The DS1721 offers thermostatic functionality with over-temperature (T_H) and under-temperature (T_L) user-programmable trip-points stored in on-chip SRAM. The two trip-points provide programmable thermostat hysteresis: the thermostat output is asserted when the measured temperature exceeds T_H and it remains active until the temperature falls below T_L.

The DS1721 is available in 150mil 8-pin SO (DS1721S) and 8-pin μMAX/μSOP (DS1721U) packages. For applications requiring higher precision, the DS1631 provides ±0.5°C accuracy and is functionally compatible with the DS1721.