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My concern is that pins are connected between DB25 and TXS0108E, but are not connected between TXS0108E and the Header 5x2. There is only the tracks between TXS0108 and the Header 5x2, but there is no connection, the pins were not all soldered.

I can not guarantee that the respective pins connected to DB25 will not be energized, eventualy they can be. So, my doubt is, is there a problem if some pins connected in the DB25 does not have their respective pins connected to Header 5x2 ? This way they will be floating in on side and not in the other of the TXS0108.

Below is the circuit to illustrate.

enter image description here

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    \$\begingroup\$ Each A-port I/O has a pull-up resistor (R PUA ) to V CCA and each B-port I/O has a pull-up resistor (R PUB ) to V CCB . R PUA and R PUB have a value of 40 kΩ when the output is driving low. R PUA and R PUB have a value of 4 kΩ when the output is driving high. R PUA and R PUB are disabled when OE = Low. \$\endgroup\$ – Sunnyskyguy EE75 Apr 2 at 17:26
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    \$\begingroup\$ Can you re-phrase your concern about floating CMOS inputs and unsoldered connections? It's not clear to me. \$\endgroup\$ – Sunnyskyguy EE75 Apr 2 at 18:00
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    \$\begingroup\$ If you need to know it is disconnected OR inactive then use a pull-down R \$\endgroup\$ – Sunnyskyguy EE75 Apr 2 at 18:05
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    \$\begingroup\$ that depends on situation and debugging bad connections \$\endgroup\$ – Sunnyskyguy EE75 Apr 2 at 18:11
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    \$\begingroup\$ @Daniel are you hot plugging anything on the connectors? \$\endgroup\$ – laptop2d Apr 2 at 18:52
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This is from the TXS0108E datasheet:

enter image description here

it shows the input detection circuitry. Rpua and Rpub are 40k

The real question is: what happens if the input drivers are left floating?

Nothing, the chip already has internal pull ups. This also means there would need to be a fairly high noise source current on the pins to get the signal to transition, which is highly, highly, unlikely and would transitions would only happen in worst case conditions. (you'd have to turn that floating pin into an antenna, and get more than ~100uA through the antenna to create a voltage edge transition the first port to get a transition on the other port). I would suggest that the inputs can be left floating and not have any serious problems.

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