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1-Wire Ambient Temperature Sensor

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

Product Details

Key Features

Parametric specs for Temperature Sensors
Sensor Type Local
# Channels One
Interface 1-Wire
Accuracy (±°C) 0.5
Parasite Pwr. Yes
Temp. Thresh. Programmable (NV)
Temp. Resolution (bits) 9
10
11
12
Oper. Temp. (°C) -55 to +125
Package/Pins TO92/3
Budgetary
Price (See Notes)
1.38
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Simplified Block Diagram

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Parameters

Parametric specs for Temperature Sensors
Sensor Type Local
# Channels One
Interface 1-Wire
Accuracy (±°C) 0.5
Parasite Pwr. Yes
Temp. Thresh. Programmable (NV)
Temp. Resolution (bits) 9
10
11
12
Oper. Temp. (°C) -55 to +125
Package/Pins TO92/3
Budgetary
Price (See Notes)
1.38

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

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.

Simplified Block Diagram

MAX31820: Block Diagram MAX31820: Block Diagram Zoom icon

Technical Docs

Support & Training

Search our knowledge base for answers to your technical questions.

Filtered Search

Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal .