1-Wire Digital Thermometer with Sequence Detect and PIO

First 1-Wire Digital Temperature Sensor with Chain-Mode Function and GPIO


The DS28EA00 is a digital thermometer with 9-bit (0.5°C) to 12-bit (1/16°C) resolution and alarm function with nonvolatile (NV), user-programmable upper and lower trigger points. Each DS28EA00 has its unique 64-bit registration number that is factory-programmed into the chip. Data is transferred serially through the 1-Wire® protocol, which requires only one data line and a ground for communication. The improved 1-Wire front end with hysteresis and glitch filter enables the DS28EA00 to perform reliably in large 1-Wire networks. Unlike other 1-Wire thermometers, the DS28EA00 has two additional pins to implement a sequence detect function. This feature allows the user to discover the registration numbers according to the physical device location in a chain, e.g., to measure the temperature in a storage tower at different height. If the sequence detect function is not needed, these pins can be used as general-purpose input or output. The DS28EA00 can derive the power for its operation directly from the data line ("parasite power"), eliminating the need for an external power supply.
DS28EA00: Typical Operating Circuit DS28EA00: Typical Operating Circuit Enlarge+

Key Features

  • Digital Thermometer Measures Temperatures from -40°C to +85°C
  • Thermometer Resolution is User-Selectable from 9 to 12 Bits
  • Unique 1-Wire Interface Requires Only One Port Pin for Communication
  • Each Device has a Unique 64-Bit Factory-Lasered Registration Number
  • ROM Multidrop Capability Simplifies Distributed Temperature-Sensing Applications
  • Improved 1-Wire Interface with Hysteresis and Glitch Filter
  • User-Definable Nonvolatile (NV) Alarm Threshold Settings/User Bytes
  • Alarm Search Command to Quickly Identify Devices Whose Temperature is Outside of Programmed Limits
  • Standard and Overdrive 1-Wire Speed
  • Two General-Purpose Programmable IO (PIO) Pins
  • Chain Function Sharing the PIO Pins to Detect Physical Sequence of Devices in Network
  • Operating Range: 3.0V to 5.5V, -40°C to +85°C
  • Can be Powered from Data Line
  • 8-Pin µSOP Package


  • Any Rack-Based Electronic System
  • Climate Control
  • Data communication equipment
  • Process Temperature Monitoring
  • Servers
  • Wireless Basestations
Part Number Sensor Type Functions Interface Channels Accuracy
Parasite Pwr. Temp. Thresh. Temp. Resolution
Multi Droppable Oper. Temp.
Package/Pins Budgetary
See Notes
DS28EA00  Local Chain Mode Function 1-Wire One 0.5 Yes Programmable (NV)
Yes -40 to +85
$2.30 @1k
See All Temperature Sensors (112)
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.

DS28EA00EVKIT: Evaluation Kit for the DS28EA00

Tools & Models

S6LX9 PicoBlaze1-Wire Project Files for ISE14.2

Related Resources