I2C splitter

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Revision as of 13:56, 24 October 2014 by Rew (talk | contribs) (using the board)

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general info

Based on the PCA9548A chip from NXP

I2C address:
1110 000 tru 1110 111 (jumper selectable)

Each I2C output has 4K7 pull-up resistors.

physical dimensions

  • Board outline: 50x25mm
  • Mounting hole diameter: 3mm
  • Mounting hole pitch: 44x19mm (3mm from board edge)


Hold the board such that the 4x8 pin array is on the left.

The 4x8 array has from left to right, GND (labeled "V-" because "GND" didn't fit), SDA (labeled DA), SCL (CL), and VCC (V+).

From top to bottom you will find bus 0 at the top to bus 7 at the bottom.

Connect your "master device" to the connector on the left or right. The pinout is GND, SDA, SCL, VCC from bottom to top.


address jumpers

It is recommended you use address 0 for the PCA9548A, unless that clashes with something on your I2C bus. Put all three jumpers to the position nearest you, in the position marked "0".

Power jumper/power connector

If your board has a jumper labeled "VOUT" near the bottom, this can be used to select the voltage level on the output bus. Connect a jumper on the rightmost two pins (AUX/VCC) to use the power from the "master" connector on the left or right of the PCB. If that is undesired, for example if your slave devices are 3.3V, you can connect a 3.3V power source to the ground pin on the left and the VAUX pin in the middle.

using the board