DS9490R Datasheet, PDF (2/6 Pages) Maxim Integrated Products – USB to 1-Wire/iButton Adapter

Figure 1. DS9490R
DS9490
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
2 of 6