TPS65381A-Q1: ttri and td1

Hi Wayne Liu,

I will try to reproduce the behavior you have describe above. Could you please provide additional information regarding your test setup.

Are those captures from a TPS65381EVM?

Regards,
Ivan

Ivan,

Thanks.  It is from customer’s board.

Hi Wayne Liu,

Thank you for the clarification. I reviewed the oscilloscope images you sent and I have a couple of comments.

With respect to ttri:

• The SDO is transitioning to tri-state almost immediately after NCS transitions from low to high.
• The slow ramp you are observing is related to the  RC response in the line, which is board dependent.

With respect to td1:

• The first marker should be position closer to 0.2 V (which is the actual digital output level in the datasheet) and the second marker move to the point where the line is starting to transition to low state. 

Ivan,

Thank you, this is very clear.

Just double confirm, so my waveforms are normal and match the datasheet, right?