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PCA9548A: If the slave address is the same as the host address, How to solve the issue for PCA9548A?

Part Number: PCA9548A

Hi team,

The customer is using PCA9548A as the MCU expansion I/O ports. 

If the host address is 000(A2 A1 A0) for PCA9548A, and a slave address is also 000 under the I2C0 bus.

then the customer needs to interview the slave that the address is 000 under the I2C0 bus like the attach.

That is the customer needs to interview the slave 1 and its address is also 000.

This maybe interviewed the  PCA9548A  host address 000, how to interview  the slave 1?

Best Wishes,
Mickey Zhang
Asia Customer Support Center
Texas Instruments

  • Hello Mickey,

    The PCA9548A can have 1 of 8 address, which are seen in Table 1. of the datasheet, I have attached below.

    Lets assume that the slave has one of the addresses above, for example hex 0x70, then you must change the address of the PCA9548A by changing one of the three address pins.  We can hardwire A0 pin to Vcc, A1 and A2 pins go GND and then the PCA9548A's address will then be 0x71.  In I2C all the devices on the bus must have unique addresses or else you will have conflicts.  Do you understand?  Let me know if you have questions.

    -Francis Houde