MAX31820PAR:1-Wire Parasite-Power, Ambient Temperature Sensor

Parasite-Powered Digital Temperature Sensor in TO-92 Package Minimizes Wiring and is Ideal for Measuring Ambient Temperature

The MAX31820PAR 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 1-Wire® bus that, by definition, requires only one data line (and ground) for communication with a central microprocessor. In addition, the device derives power directly from the data line (“parasite power”), 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 MAX31820PAR has a unique 64-bit serial code, which allows multiple MAX31820PAR devices to function on the same 1-Wire bus. Therefore, it is simple to use one microprocessor to control many devices distributed over a large area.

Key Features
  • Unique 1-Wire Interface Requires Only One Port Pin for Communication
  • Derives Power from Data Line (Parasite Power); No Local Power Supply Needed
  • Multidrop Capability Simplifies Distributed Temperature-Sensing Applications
  • Requires No External Components
  • 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-PAR and DS18B20-PAR
MAX31820PAR: Block Diagram
MAX31820PAR: Block Diagram
Applications/Uses
  • Any Thermally Sensitive System
  • Consumer Products
  • HVAC Environmental Controls
  • Industrial Systems
  • Process Monitoring and Control Systems
  • Temperature Monitoring Systems Inside Buildings, Equipment, or Machinery
  • Thermometers
  • Thermostatic Controls
DataSheet
titleDownload file
MAX31820PAR Data SheetMAX31820PAR.pdf
Parametrics
Part NumberSensor TypeInterfaceChannelsAccuracy
(±°C)
Parasite Pwr.Temp. Thresh.Temp. Resolution
(bits)
Multi DroppableOper. Temp.
(°C)
Package/PinsBudgetary
Price
See Notes
MAX31820PARLocal1-WireOne0.5YesProgrammable (NV)9
10
11
12
Yes-55 to +100TO92/3$1.12 @1k
Related Products
  • DS1822-PAR:Econo Parasite-Power Digital Thermometer
  • DS18B20-PAR:1-Wire Parasite-Power Digital Thermometer
Ordering Information
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX31820PARMCR+ActiveTO92,;3 pin;19.5 mm²-55°C to +125°CLead Free
MAX31820PARMCR+TActiveTO92,;3 pin;27.6 mm²-55°C to +125°CLead Free
MAX31820PAR.pdf MAX31820PAR
Create a 1-Wire Master with Xilinx PicoBlaze DS1990A
Understanding the DS1WM Synthesizable 1-Wire Bus Master DS1923
Introduction to Medical Instruments and Growing Trend for Point-of-Care and Near-Patient Testing MAX31820PAR
Comparison of the DS18B20 and DS18S20 1-Wire® Digital Thermometers MAX31820PAR
Package Thermal Resistance Values (Theta JA, Theta JC) for Temperature Sensors and 1-Wire Devices MAX31826
Single-Wire Serial Bus Carries Isolated Power and Data MAX31826
1-Wire Master Device Configuration DS1920
White Paper 5: Using 1-Wire APIs for Data Sheet Commands DS1921K
Curve Fitting the Error of a Bandgap-Based Digital Temperature Sensor MAX31820PAR
DS18B20-PAR/DS18S20-PAR/DS1822-PAR Advantages for Remote Temperature Sensing MAX31820PAR
Interfacing the DS18X20/DS1822 1-Wire® Temperature Sensor in a Microcontroller Environment MAX31820PAR
MAX31820PAR.pdf MAX31820PAR