One-Wire Ambient Temperature Sensor - MAX31820SPARKFUN33日以内出荷
DescriptionThe MAX31820 ambient temperature sensor provides 9-bit to 12-bit Celsius temperature measurements with ±0.5℃ accuracy over a +10℃ to +45℃ temperature range. Over its entire -55℃ to +125℃ operating range, the device has ±2.0℃ accuracy.The device communicates over a one-wire bus that, by definition, requires only one data line(and ground)for communication with a central microprocessor. In addition, the device can derive power directly from the data line, eliminating the need for an external power supply. Requiring so few pins enables the device to be placed in a 3-pin TO-92 package. The form factor of this package allows the device to be placed above the board and thus measure the ambient temperature of a system, as opposed to the board temperature that a surface-mount package would measure.Each MAX31820 has a unique 64-bit serial code, which allows multiple MAX31820 devices to function on the same one-wire bus. Therefore, it is simple to use one microprocessor to control many devices distributed over a large area.FeaturesUnique one-wire interface requires only one port pin for communicationEach device has a unique 64-bit serial code stored in onboard ROMMultidrop capability simplifies distributed temperature-sensing applicationsRequires no external componentsCan be powered from data line; 3.0V to 3.7V power-supply rangeMeasures temperatures from -55℃ to +125℃±0.5℃ accuracy from +10℃ to +45℃Thermometer resolution is user-selectable from 9 bits to 12 bitsConverts temperature to 12-bit digital word in 750ms(Max)User-definable nonvolatile(NV)alarm settingsAlarm search command identifies and addresses devices whose temperature is outside programmed limits(Temperature Alarm Condition)Available in 3-pin TO-92 packageTO-92 package allows measurement of ambient temperatureSoftware compatible with the DS1822 and DS18B20