DS9490R USB to 1-Wire Adapter

DS9490R USB to 1-Wire Adapter
DS9490R USB to 1-Wire Adapter
DS9490R Adapter Pinout
DS9490R USB to 1-Wire Adapter
DS9490R Adapter Pinout

click on image to enlarge

Connector Description






Can be connected to USB2.0 or USB3.0 port of laptop/computer



An RJ14 or RJ11 connector can be connected to this terminal, the other end is normally connected to a sensor or array of sensors following the 1-Wire protocol


DS9490R Specifications

  • Interface 1-Wire sensors like DS18B20 or iButton with Computer
  • Supports 12Mbps USB standard
  • Contains internal pull up resistor
  • Works on DS2401 identification Chip
  • Can read and write data over 1-Wire
  • Supports array of sensors on the RJ11 end

Note: The DS9490R datasheet can be found at the bottom of the page


Alternative to DS9490R

While DS9490R works fine with the DSXX series sensors, it gets a bit troublesome to use a direct connector along with DS9490R while working with iButton. So Maxim has another variant called DS9490B which has a dedicated holder for iButton.


Where to use DS9490R

The DS9490R is a simple USB to 1-Wire connector. Maxim has a wide range of sensors and other devices that work with 1-Wire protocol. When there is a need to connect these sensors/devices to the computer, the one-wire connection has to convert to USB, which exactly is done by this DS9490R connector. It has the RJ11 port on one end which has to be connected to the sensor/device thorough a cable. It is also feasible to connect an array of sensor to this RJ11 port. So if you are looking for a connector to interface your 1-Wire sensor to your computer then DS9490R might be of interest to you.


How to use DS9490R

The DS9490R is a USB bridge between your PC and a one-Wire protocol sensor. Before connecting the connector to the computer, the sensor has to be connected to the RJ11 port on this connector. As we know every one-wire sensor will have two wires one is the signal/IO (a.k.a 1-Wire Data) and the other is ground (a.k.a 1-Wire Return).

The RJ11 port has 6 pins in total out which we will use only 4 for our application. The Vdd(5v) and Ground can be used to power the sensor and the OW pin is connected to the signal/IO pin of the sensor and the GND_OW pin is connected to the ground pin of the sensor. Note that the signal ground (pin4) is different from the power ground (pi n 2). A symbolic representation of the same is given below


You can also connect multiple sensors in an array fashion to the RJ11 connector. When the DS9490R is plugged in a computer it should automatically recognize it since it operates on the standard DS2401 IC so it follows the 64-bit ID. For more details on how the data is received from one-wire to USB please refer the datasheet at the end of this page.  



  • To read values form sensors like DS18B20,DS1402D etc..
  • To communicate with iButton devices
  • Interface 1-Wire protocol with USB
  • Read and Configure iButton devices.


2D – model

DS9490R Dimensions

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