That does not mean that this adapter is designed for 3.3V operation! CH341A chip itself is powered from 5V USB directly, so the voltage on its logical outputs will be around 5V as well. This adapter requires modification to work with 3.3V chips.
That does not mean that this adapter is designed for 3.3V operation! CH341A chip itself is powered from 5V USB directly, so the voltage on its logical outputs will be around 5V as well. This adapter requires modification to work with 3.3V chips.