Features and Benefits
- 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
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.
- Any Thermally Sensitive System
- Consumer Products
- HVAC Environmental Controls
- Industrial Systems
- Process Monitoring and Control Systems
- Temperature Monitoring Systems Inside Buildings, Equipment, or Machinery
- Thermostatic Controls
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Documentation & Resources
UG-4277: Getting Started with the MAXQ2000 USB Thumb Evaluation Kit9/24/2008301K
1-Wire Search Algorithm3/28/2002
Simple Software Validates the Hardware CRC and Detects Errors in the Serial Bit Stream of 1-Wire® Thermal Devices9/25/2009
Comparison of the DS18B20 and DS18S20 1-Wire® Digital Thermometers3/18/2009
Single-Wire Serial Bus Carries Isolated Power and Data3/23/2006
DS18B20-PAR/DS18S20-PAR/DS1822-PAR Advantages for Remote Temperature Sensing8/27/2002
Create a 1-Wire Master with Xilinx PicoBlaze2/27/2023
Advanced 1-Wire Network Driver2/14/2023
Overview of Sensor Signal Paths5/12/2010
Introduction to Medical Instruments and Growing Trend for Point-of-Care and Near-Patient Testing5/10/2010
Thermal Management Handbook5/4/2010
How to Power the Extended Features of 1-Wire® Devices6/17/2008
Package Thermal Resistance Values (Theta JA, Theta JC) for Temperature Sensors and 1-Wire Devices11/16/2006
1-Wire Master Device Configuration3/3/2004
1-Wire Communication with a Microchip PICmicro Microcontroller9/16/2003
Curve Fitting the Error of a Bandgap-Based Digital Temperature Sensor6/20/2002
White Paper 5: Using 1-Wire APIs for Data Sheet Commands6/7/2002
1-Wire® Tagging with XML6/7/2002
1-Wire Communication Through Software5/30/2002
Using the DS2480B Serial 1-Wire® Line Driver3/12/2002
Interfacing the DS18X20/DS1822 1-Wire® Temperature Sensor in a Microcontroller Environment3/8/2002
Guidelines for Reliable Long Line 1-Wire Networks11/16/2001
Understanding and Using Cyclic Redundancy Checks with Maxim 1-Wire and iButton Products3/29/2001
MAX31820PAR Companion Parts
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