Maxim > Products > 1-Wire Devices > DS9490, DS9490B, DS9490R
Maxim > Products > iButton Devices > DS9490, DS9490B, DS9490R

DS9490, DS9490B, DS9490R

USB to 1-Wire/iButton Adapter

 Overview   Design Resources   Ordering Info   Related Products   All   

Status Explanations for product status codes

Part Number Status
DS9490 Active: In Production.
DS9490B Active: In Production. See Ordering Information for details.
DS9490R Active: In Production. See Ordering Information for details.


The DS9490B is a USB bridge and holder for a single F5-size iButton®. The iButton is securely held behind a latched door. The DS9490R is a USB bridge with 1-Wire® RJ11 interface to accommodate 1-Wire receptacles and networks. For a list of suitable 1-Wire network cables, refer to the Connectivity Matrix table in the DS1402x 1-Wire network cables data sheet. Both adapters are based on the DS2490 USB-to-1-Wire bridge chip. Free software drivers for Windows®-based PCs can be downloaded from

Data Sheet

Download this datasheet in PDF formatDownload Rev 3 (PDF, 240kB)
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Key Features

  • High-Speed 12Mbps Universal Serial Bus (USB) Interface
  • Supports Standard and Overdrive 1-Wire Communication
  • Slew-Rate-Controlled 1-Wire Timing and Active Pullup for Improved 1-Wire Network Performance
  • DS9490R has an RJ11 Interface for Standard Connectivity Accessories such as the DS1402D-DR8
  • DS9490B has an iButton Interface and Retains a Fixed iButton
  • Built-In Custom DS2401 Identification Chip
  • Reads all 1-Wire and iButton Devices. Writes All Except EPROM 1-Wire/iButton Devices


  • iButton Initialization and Download
  • Demonstration
  • Development
  • Software Authorization

Key Specifications:

iButton Readers and Adapters
Part Number Overview Features Budgetary
See Notes
DS9490B  9490B_sm
DS9490B USB iButton Holder
F5 Package Compatible
Permanently/Semi-permanently Retains an iButton
USB Port
USB Port Adapters
With ID
$14.03 @1k
DS9490R  9490R_sm
USB to 1-Wire RJ11
USB Port
USB Port Adapters
With ID
See All iButton Readers and Adapters (24)

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.


DS9490, DS9490B, DS9490R: Typical Operating Circuit
Typical Operating Circuit

More Information

Software Authorization Kit (a free software development kit with source)

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Information Index



Design Resources


Ordering Info


Related Products

Key Features
Key Specifications
Notes and Comments
  Data Sheet
Technical Documents
Evaluation Kits
Reliability Reports
  Price and Availability
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Package Information
Lead-Free Information
  Similar Products by Function
Similar Products by Application
Evaluation Kits
Products with Similar Part Numbers
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Document Ref.: 19-4881 Rev 3; 2011-06-13
This page last modified: 2013-03-01