TCA39306: IBIS model usage of TCA39306

edward lee

Part Number: TCA39306

Hi :

I downloaded IBIS models of TCA39306 and tried to simulate if a TCA39306 can communicate with 6 TCA39306 through a cable. Do you know how to set the IBIS model to input mode and output mode for SCL and SDA pins?

Thanks

2 months ago

0 Tyler Townsend 2 months ago

TI__Guru 55728 points

Hi Edward,

What program are you using to simulate the TCA39306?

Regards,

Tyler

0 edward lee 2 months ago in reply to Tyler Townsend

Prodigy 20 points

Hi Tyler:

We use ADS to simulate.

Thanks

0 Tyler Townsend 2 months ago in reply to edward lee

TI__Guru 55728 points

Hi Edward,

This is how I was able to simulate the input vs. output using the IBIS pin model.

Regards,

Tyler

0 edward lee 2 months ago in reply to Tyler Townsend

Prodigy 20 points

Hi Tyler:

I follow the connection and it works. However, I found the output voltage only can reach to 2.0V instead of 3.3V.

Could you please check if it is the same as your schematic?

Thanks

Edward

0 Tyler Townsend 2 months ago in reply to edward lee

TI__Guru 55728 points

Hi Edward,

I will need extra time to debug. Let me check on this tomorrow.

Regards,

Tyler

0 Tyler Townsend 2 months ago in reply to edward lee

TI__Guru 55728 points

Hi Edward,

I think the model is struggling because a push-pull driver is being used. Is there a way to make an open-drain driver at the "IN" input.

Regards,

Tyler

0 edward lee 2 months ago in reply to Tyler Townsend

Prodigy 20 points

Hi Tyler:

We might have to use push-pull model on MCU side to reach up to 12.5Mhz clock rate. Will TI update the model to use push-pull driver source.

Thanks

0 Tyler Townsend 2 months ago in reply to edward lee

TI__Guru 55728 points

Hi Edward,

Try using the 1.5V model to see if this works? I think the 3.3V model sets the EN pin voltage to 3.3V, which wouldn't allow the output side to rise.

The 1.5V should set the EN = 1.5V, then the output should be able to rise to 3.3V with the assistance of a PU resistor.

Regards,

Tyler

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TCA39306: IBIS model usage of TCA39306