DS9490R_11 Datasheet, PDF (2/6 Pages) Maxim Integrated Products – USB to 1-Wire/iButton Adapters High-Speed 12Mbps Universal Serial Bus (USB) Interface

Figure 1. DS9490R
DS9490R/DS9490B
Figure 2. DS9490B
*Note: To eject an iButton, insert a straightened paper clip into the side access hole of the DS9490B. Push
the paper clip in the direction of the iButton. A different iButton can then be inserted. The data
contact faces down and away from the embossed ‘i’. Before inserting the paper clip disconnect the
DS9490B from the USB bus.
Each USB bridge contains a unique built-in identification chip. The identification chip is a custom DS2401
that is a 64-bit ID number (see Figure 3).
Figure 3. DS2401 ID CHIP 64-BIT LASERED ROM
MSB
LSB
8-BIT
CRC CODE
MSB
LSB
12-BIT
FIXED
(000h)
36-BIT SERIAL
NUMBER
8-BIT FAMILY
CODE (81h)
MSB
LSB MSB
LSB MSB
LSB
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