What's wrong with my simulation for Bi-directional logic level converter?
That kind of logic level converter circuit requires an active pull-down on the input when you're intending to feed it a 0 level.
Simply floating the input will not work since (as you can see in the schematic) it has a pull-up resistor to the supply.
To get your simulation to work there are 2 things you can do:


remove the 3.3V source on your input and simply tie the switch from the input to ground
replace the DC voltage source &amp; switch with a square-wave source