TUSB216: RX_SEN Vih voltage level

Hi Makoto-san,

Here are the levels of voltage needed to hit the high level voltage input, these can be found in the datasheet:

Unfortunately, I do not believe you will be able to hit the minimum amount of voltage for RX_Sen to be read as high in a 5V system. Swapping the resistors would fix this though.

Please let me know if you have any other questions or concerns.

Thanks,

Ryan

Dear Ryan-san,

Thank you for your replying.

Vih(Min) is 75% of the VCC. This voltage is 3.75V in the 5V system.

But this voltage exceed Recommended Operating Conditins in the datasheet:

So I would like to know true voltage of the Vih(Min) of the RX_SEN.

Best regards,

Makoto Yamaguchi

Hi Makoto-san,

In this case, currently I would recommend increasing the value of the 12KOhm resistor to 15kOhm, just as the referenced E2E thread does. This should divide the voltage enough to reduce the voltage to about 3.5V.

There does seem to be some conflict in information though regarding what level of voltage reads as high for RXSen, I will ask around to see if there has been anything done to update this info and get some concrete information back to you.

Thanks,

Ryan

Hi Makoto-San,

After asking and looking around, it sounds like it would be best to try increasing the value of that resistor to 15KOhm. Going against the spec specified by the datasheet may lead to problems.

If you see any issues with your eyes/signals after changing that resistor, I would recommend looking at the TUSB216I, as this part is capable of dealing with 5V at the RX_Sen pin, and has recommendations for RX_Sen voltages at a VCC of 5V.

Thanks,

Ryan

Dear Dyan-san,

Sorry for my late replying. And thank you for your information.

Best regards,

Makoto Yamaguchi