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TCA9535 does not work(PCA9535 same S/W)

Shuichi Uno
Prodigy 130 points
Other Parts Discussed in Thread: TCA9535, PCA9535

Hi

My customers are replaced by the TCA9535 from PCA9535.
Customer was replaced in TCA9535, but it does not work.

xCA9535 has control from the MCU.

I have confirmed the data sheet, has been defined as the same in 6.6
I2C Tiing Interface.
We understand that there is no change in the timing of as hardware.


But in TCA9535 There are some of the additional section in the data sheet.

I have for the purpose of postscript, i will need to change the MCU of
the software?

Regards

Shuichi Uno

  • 0
    TI__Intellectual 2175 points

    Hi Uno-san,

    TCA9535 has the same register maps and address as the PCA9535. The software does not need to be changed going from PCA9535 to TCA9535.

    Here are the main difference between PCA9535 and TCA9535:

    • TCA supports lower voltage operation (down to 1.65V VCC) compared to PCA (down to 2.3V VCC)
    • TCA has improved POR circuit which supports different power supply ramps. PCA has limitation on power supply ramping rates.

    The timing section (6.6) for PCA and TCA are the same as both devices support I2C specification. They look slightly different since TCA9535 mentions both I2C standard and fast mode timing, PCA9535 only mentions Fast mode timing parameters (although PCA9535 also supports standard mode I2C timings).

    Can you let us know in more detail what issue you see when you replace PCA with TCA? Does the TCA device acknowledge the slave address correctly?

    Thanks,

    Rajan

  • 0 in reply to Rajan Arora
    Prodigy 130 points
    Rajan-san,
    Thank you for your quick reply.

    More detail is as belows.

    I check the data sheet of the two devices.
    PCA9535 There are documented in the data sheet on page 17.
    TCA9535 There are documented in the data sheet on page 19.
    Two of the descriptive content is the same thing.

    H / W and there is no change to the MCU of the software.

    Also commands that are issued to xCA9535 the same thing.
    My customer is the slave address of the PCA9535 is 0x40.
    Slave address of TCA9535 is also the same.
    ACK also been received.

    Command to be sent from the master has issued the same command.
    H / W is the same.
    The electrical characteristics of the device.
    could you tell me why the operation is different?

    Best Regards,
    Shuichi Uno
  • 0 in reply to Shuichi Uno
    TI__Genius 16510 points
    Uno-san,

    Can you explain how the operation is different for the customer? The two devices should behave exactly the same. Only changes to the TCA9535 is lower voltage support and POR errata fix.

    What command are they sending to the xCA9535 and what are they seeing for each device?