The DS1631, DS1631A, and DS1731 digital thermometers provide 9, 10, 11, or 12-bit temperature readings over a -55°C to +125°C range. The DS1631 and DS1631A thermometer accuracy is ±0.5°C from 0°C to +70°C with 3.0V ≤ VDD ≤ 5.5V, and the DS1731 accuracy is ±1°C from -10°C to +85°C with 3.0V ≤ VDD ≤ 5.5V. The thermostat on all three devices provides custom hysteresis with user-defined trip points (TH and TL). The TH and TL registers and thermometer configuration settings are stored in NV EEPROM so they can be programmed prior to installation. In addition, the DS1631A automatically begins taking temperature measurements at power-up, which allows it to function as a stand-alone thermostat. Communication with the DS1631/DS1631A/DS1731 is achieved through a 2-wire serial interface, and three address pins allow up to eight devices to be multidropped on the same 2-wire bus.