USB to 1-Wire/iButton Adapter


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 www.maximintegrated.com/1-Wiredrivers.
DS9490B, DS9490R: Typical Operating Circuit. DS9490B, DS9490R: Typical Operating Circuit. Enlarge+

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
Part Number Overview Budgetary
See Notes
DS9490B  9490B_sm
DS9490B USB iButton Holder
$18.32 @1k
DS9490R  9490R_sm
USB to 1-Wire RJ11
$20.23 @1k
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.

Technical Documents

App Note 5917 Instructions for Compiling the OneWireViewer for Linux
Reference Schematic 4206 Choosing the Right 1-Wire® Master for Embedded Applications
User Guide 3358 OneWireViewer User's Guide, Version 1.5
App Note 1740 White Paper 6: 1-Wire® Drivers Installation Guide for Windows

Quality and Environmental Data

Product Reliability Reports: DS9490.pdf 
Lead-Free Package Tin (Sn) Whisker Reports

Additional Resources

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

Related Resources