raschemmel:
Well I don't know what all the fuss is about. I never had a problem with one of these.or
They both work the same way. The output voltage is determined by the Vcc. (3.3V or 5V).
The device is 5V tolerant when running on 3.3V.Therefore, if you THINK about it, you CANNOT use the SAME chip to go BOTH ways.
If you have some signals that need to go from 3.3V to 5V, you need one chip dedicated to that purpose. If you have OTHER signals that need to go from 5v to 3.3V you need ANOTHER chip didicated to that purpose. In the case of the OP's application, IF he had purchased the XTB instead of the XTS,
he could use the SAME chip because it is BIDIRECTIONAL. I stated that he does NOT have a BIDIRECTIONAL application because he does NOT in point of fact, have a single signal that must go BOTH directions. All of the signals in his circuit are either 3.3V to 5V OR 5V to 3.3V. That makes it a MONODIRECTIONAL application. That being said, there is ,in fact some convenience in being able to accomplish both directions with ONE chip, even if NONE of the signals are going BOTH ways.
The XTB should be capable of doing this because it has TWO supply voltage inputs and it is bidirectional so signals can go either way. It is , however NOT necessary , for the reasons given, and offers only the convenience I described in the case of the OP's application. I happen to have the XTB and NOT the XTS but have had issues with insufficient bias current to change the direction of the signal so I rely on something foolproof like the two chips linked above . These have never failed to perform the required function.
Hello there,
Some of the converters i had seen have MOSFETs for converting from one to the other level. I believe the MOSFET stays off if the +3.3v line becomes disconnected, so maybe that's ok then.