This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

PCA9306: About use with AM57xx

Part Number: PCA9306
Other Parts Discussed in Thread: LSF0102

Dear TI Team

Our customers are considering the PCA9306 as a buffer on the AM57xx I2C line.

When I check the schematic checklist of AM57xx, it says the following, and I think that it cannot be used with PCA9306. Is it correct?
(I think that PCA9306 can be used if 3.4Mbps I2C is not used.)

Best Regards,

  • The PCA9306 is a passive switch. It does not really care about the falling edges; the other devices connected to the bus must be able to handle them.

  • Hi Ladisch,

    Thank you for your reply.

    In other words, can PCA9306 be used as a buffer for 3.4Mbps I2C?
    You said "the other devices connected to the bus must be able to handle them." What kind of devices need to comply with the check list's falling edge rules?

    Hi TI Team

    I would also like to hear from the TI Team about the questions I posted.
    I would be grateful if anyone from the TI Team could answer.


  • Yes, the PCA9306 will work with 3.4 MHz I²C.

    All other I²C devices must be able to handle the I²C signals generated by the AM57xx.

  • Hi Y.Ottey,

    I need to point out that PCA9306 is not an I2C buffer, only a level translator. 

    Technically the PCA9306 can support the 3.4MHz range but you may see some 'artifacting' from the device where it may hang around the Vg-Vth voltage during the rise and fall times and may last double digit nanoseconds. 

    I'm not as familiar with the I2C standard outside of 1MHz but I believe the I2C bus turns into push pull when your in those higher speed ranges and ACKs are no longer supported at that speed. Common I2C speeds usually are 100kHz and 400kHz, when higher speeds are needed people usually flock to a different protocol like SPI. 


  • Hi BOBBY

    Thank you for your reply.

    I understand that the PCA9306 is just a level shifter and that there are problems with the PCA9306.

    For LSF0102, can it be used as a buffer for 3.4Mbps I2C?
    (Does the above AM57xx 3.4Mbps I2C line fall edge requirement meet?)

    This device is a level shifter similar to PCA9306, but I confirmed that it is an IC that supports signals up to 100MHz.

    Best Regards,

  • PCA9306 and LSF0102 are essentially the same device. Both support the same frequencies.

  • Hi Ladish

    Thank you for your reply.

    Hi BOBBY

    I would appreciate your feedback on my additional questions.


  • Y.Ottey,

    Clemen's response is correct. Both will technically support 3.4Mbps/MHz  under the right conditions.