MAX31820

1-Wire Ambient Temperature Sensor

Digital Temperature Sensor in TO-92 Package Ideal for Measuring Ambient Temperature


Please check latest availability status for a specific part variant.

Description

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 1-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 (“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 MAX31820 has a unique 64-bit serial code, which allows multiple MAX31820 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.
MAX31820: Block Diagram MAX31820: Block Diagram Enlarge+

Key Features

  • Unique 1-Wire Interface Requires Only One Port Pin for Communication
  • Each Device has a Unique 64-Bit Serial Code Stored in On-Board 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
  • TO-92 Package Allows Measurement of Ambient Temperature
  • Software Compatible with the DS1822 and DS18B20

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
Part NumberSensor TypeInterfaceChannelsAccuracy
(±°C)
Parasite Pwr.Temp. Thresh.Temp. Resolution
(bits)
Multi DroppableOper. Temp.
(°C)
Package/PinsBudgetary
Price
See Notes
MAX31820 Local1-WireOne0.5YesProgrammable (NV)
9
10
11
12
Yes-55 to +125
TO92/3
$1.12 @1k
See All Temperature Sensors (113)
Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.

Technical Documents

Reference Schematic 5508 Create a 1-Wire Master with Xilinx PicoBlaze
App Note 5507 Understanding the DS1WM Synthesizable 1-Wire Bus Master
Tutorial 4700 Introduction to Medical Instruments and Growing Trend for Point-of-Care and Near-Patient Testing
Tutorial 4699 Overview of Sensor Signal Paths
Tutorial 4679 Thermal Management Handbook
App Note 4600 Simple Software Validates the Hardware CRC and Detects Errors in the Serial Bit Stream of 1-Wire® Thermal Devices
Reference Schematic 4477 Reference Design of a 1-Wire® Bidirectional Voltage-Level Translator for 1.8V to 5V
App Note 4377 Comparison of the DS18B20 and DS18S20 1-Wire® Digital Thermometers
App Note 4277 Getting Started with the MAXQ2000 USB Thumb Evaluation Kit
Tutorial 4255 How to Power the Extended Features of 1-Wire® Devices
App Note 3930 Package Thermal Resistance Values (Theta JA, Theta JC) for Temperature Sensors and 1-Wire Devices
App Note 3754 Single-Wire Serial Bus Carries Isolated Power and Data
App Note 2965 1-Wire Master Device Configuration
App Note 2420 1-Wire Communication with a Microchip PICmicro Microcontroller
App Note 1100 White Paper 5: Using 1-Wire APIs for Data Sheet Commands
Reference Schematic 244 Advanced 1-Wire Network Driver
App Note 208 Curve Fitting the Error of a Bandgap-Based Digital Temperature Sensor
App Note 192 Using the DS2480B Serial 1-Wire® Line Driver
App Note 187 1-Wire Search Algorithm
App Note 162 Interfacing the DS18X20/DS1822 1-Wire® Temperature Sensor in a Microcontroller Environment
App Note 158 1-Wire® Tagging with XML
Tutorial 148 Guidelines for Reliable Long Line 1-Wire Networks
App Note 27 Understanding and Using Cyclic Redundancy Checks with Maxim 1-Wire and iButton Products

Quality and Environmental Data

Request Reliability Report for: MAX31820 
Lead-Free Package Tin (Sn) Whisker Reports

Tools & Models

  • MAX31820 IBIS Model
  • CAD Symbols and Footprints

  • MAX31820MCR+
  • MAX31820MCR+T
  • MAX31820PARMCR+
  • MAX31820PARMCR+T
  • MAX31820SLMCR+T
  • Device   Fab Process   Technology   Sample size   Rejects   FIT at 25°C   FIT at 55°C  

    Note : The failure rates are summarized by technology and mapped to the associated material part numbers. The failure rates are highly dependent on the number of units tested.

    Quality Management System >
    Environmental Management System >

     
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    Type ID PDF Title
    Reference Schematic 5508 Create a 1-Wire Master with Xilinx PicoBlaze
    App Note 5507 Understanding the DS1WM Synthesizable 1-Wire Bus Master
    Tutorial 4700 Introduction to Medical Instruments and Growing Trend for Point-of-Care and Near-Patient Testing
    Tutorial 4699 Overview of Sensor Signal Paths
    Tutorial 4679 Thermal Management Handbook
    App Note 4600 Simple Software Validates the Hardware CRC and Detects Errors in the Serial Bit Stream of 1-Wire® Thermal Devices
    Reference Schematic 4477 Reference Design of a 1-Wire® Bidirectional Voltage-Level Translator for 1.8V to 5V
    App Note 4377 Comparison of the DS18B20 and DS18S20 1-Wire® Digital Thermometers
    App Note 4277 Getting Started with the MAXQ2000 USB Thumb Evaluation Kit
    Tutorial 4255 How to Power the Extended Features of 1-Wire® Devices
    App Note 3930 Package Thermal Resistance Values (Theta JA, Theta JC) for Temperature Sensors and 1-Wire Devices
    App Note 3754 Single-Wire Serial Bus Carries Isolated Power and Data
    App Note 2965 1-Wire Master Device Configuration
    App Note 2420 1-Wire Communication with a Microchip PICmicro Microcontroller
    App Note 1100 White Paper 5: Using 1-Wire APIs for Data Sheet Commands
    Reference Schematic 244 Advanced 1-Wire Network Driver
    App Note 208 Curve Fitting the Error of a Bandgap-Based Digital Temperature Sensor
    App Note 192 Using the DS2480B Serial 1-Wire® Line Driver
    App Note 187 1-Wire Search Algorithm
    App Note 162 Interfacing the DS18X20/DS1822 1-Wire® Temperature Sensor in a Microcontroller Environment
    App Note 158 1-Wire® Tagging with XML
    Tutorial 148 Guidelines for Reliable Long Line 1-Wire Networks
    App Note 27 Understanding and Using Cyclic Redundancy Checks with Maxim 1-Wire and iButton Products