I would like to know what Vih min voltage is when Vddext is 3.3V.
But in BF533 datasheet, there is no electrical characteristic about Vih with Vddext applied to 3.3V.
Is there anyone lets me know the specfication?
I don't have the data for VDDEXT = 3.3V. Are you trying to connect a device that has a Voh just under 2.0V?
The Vih specification in the data sheet is given at VDDEXT = 3.6V (maximum) for reliability reasons. For instance, if the voltage regulator supplying VDDEXT is nominally set at 3.3V, but could give 3.4V under certain temperature or load conditions, the Vih spec should be high enough to compensate.
Retrieving data ...