Datasheet

SNLU100 – April 2012 SERDESUB-16USB User’s Guide 9
JP4,VR3: Address Decoder
Reference Description Setting Connector
JP4
DS90UB901Q
I
2
C Device ID Address
Selection
Default address: 0xB0’h
Enabled –
With jumper
VSS –
Default address
(Default)
JP4 &
VR3
RID value adjustment
(via screw)
JP4 MUST
have a jumper to
use VR3 potentiometer.
VR3 = 0Ω to 100KΩ
Clockwise
Decreases
R
ID value
Counter-
Clockwise
Increases
R
ID value
The ID[x] (CAD) pin is used to set the physical slave address of the DS90UB901Q (I
2
C
only) to allow up to six devices on the bus using only a single pin. The Address Decoder
employs a 10 kΩ pull up resistor to +1.8V and a variable potentiometer (VR3) for the pull
down resistor R
ID
to GND to generate six unique values based on the table below. Once
the address bits are latched on power up, the device will keep the slave address until a
power down or reset condition occurs.
Figure 3. ID[x] Pin Connection Diagram