The MAX31820 ambient temperature sensor provides 9-bit to 12-bit Celsius temperature measurements with ±0.5°C accuracy over a +10°C to +45°C temperature range. Over its entire -55°C to +125°C operating range, the device has ±2.0°C 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.
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.
- Unique one-wire interface requires only one port pin for communication
- Each device has a unique 64-bit serial code stored in onboard ROM
- Multidrop capability simplifies distributed temperature-sensing applications
- Requires no external components
- Can be powered from data line: 3.0V to 3.7V power-supply range
- Measures temperatures from -55°C to +125°C (-67°F to +257°F)
- ±0.5°C accuracy from +10°C to +45°C
- Thermometer resolution is user-selectable from 9 bits to 12 bits
- Converts temperature to 12-bit digital word in 750ms (Max)
- User-definable nonvolatile (NV) alarm settings
- Alarm search command identifies and addresses devices whose temperature is outside programmed limits (Temperature Alarm Condition)
- Available in 3-pin TO-92 package
- Software compatible with the DS1822 and DS18B20