• State
  • Locked Locked
  • Replies 1 reply
  • Subscribers 33 subscribers
  • Views 111 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

TCA9539-Q1: TCA9539 I2C DATA is pulled low

xiwen Yan
Prodigy 60 points
Part Number: TCA9539-Q1
Other Parts Discussed in Thread: TCA9539,

Tool/software:

Our MCU has two TCA9539s connected to one I2C bus. 500us after operating the one with address 0x74, the I2C DATA line is pulled low probabilistically. The I2C bus recovers when this TCA9539 is reset. Have you encountered this issue before? What might be the cause? 

.

  • 0
    TI__Mastermind 47328 points

    Hi Xiwen, 

    I have not seen this issue before. 

    Are there any other I2C devices that are being reset due to pulling LOW on /RESET of TCA9539-Q1? Are the reset pins tied together? 

    Was a stop condition sent after sending 0x60? It looks to be so, but just to confirm. 

    Do we have analog scope captures of the event? 

    TCA9539-Q1 can pull LOW on SDA, but only during reading register data of the device, or when the device needs to ACK the bus. 

    Regards,

    Tyler