AM625: I2C GPIO termination

Mari Tsunoda

Part Number: AM625

Tool/software:

Hi Team,

In the FAQ below, it says that the I2C and GPIO interfaces must be terminated. However, it does not list how it should be terminated. How should they do this?

[FAQ] AM625 / AM623 / AM620-Q1 / AM625-Q1 / AM625SIP Custom board hardware design – I2C interface

Best regards,

Mari Tsunoda

2 months ago

0 Kallikuppa Sreenivasa 2 months ago

TI__Guru**** 190179 points

Hello Mari Tsunoda

Thank you for the query.

Please point me to the section that you are referencing.

Regards,

Sreenivasa

0 Mari Tsunoda 2 months ago in reply to Kallikuppa Sreenivasa

TI__Expert 5726 points

Hi Sreenivasa,

Thanks for the reply. I see that the image was not pasted... This is the section they are referring to.

Best regards,

Mari

0 Kallikuppa Sreenivasa 2 months ago in reply to Mari Tsunoda

TI__Guru**** 190179 points

Hello Mari Tsunoda

Thank you

The above note you pasted is for the open drain output type buffer based I2C interface.

The recommendation is to use pullup irrespective of the IO usage or configuration.

Regards,

Sreenivasa

0 Stanislav Stilyanov 1 month ago in reply to Kallikuppa Sreenivasa

TI__Mastermind 18030 points

Hi Mari Tsunoda,

Because these pins are implemented with open-drain output to satisfy I2C open drain bus structure, there should be external pullup resistors in I2C and in GPIO output modes for proper operation. For GPIO input mode, when it is driven with push-pull externally, generally the pullup is not required, but may be needed in some cases.

Regards,

Stan

0 Kallikuppa Sreenivasa 1 month ago in reply to Stanislav Stilyanov

TI__Guru**** 190179 points

Hi Mari Tsunoda,

For the open drain I2C interface the RX buffers are enabled after reset and hence the need to add an external pullup irrespective of the IO usage or configuration (I2C or GPIO) except in conditions where an external input is being driven after reset.

Regards,

Sreenivasa

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AM625: I2C GPIO termination