Hi,
First of all, pls download the data sheet of LPC546xx from the link:
https://www.nxp.com.cn/docs/en/data-sheet/LPC546XX.pdf
As the following screenshot from above data sheet, you can see that
typical voltage of USB1_AVDD3V3,USB1_AVDDTX3V3 pins are 3.3V
The VDD is from 1.71 to 3.6V, but if you use USB, you have to meet the following condition:
For USB full-speed operation only 3.0 - 3.6 V
For USB high-speed operation only 1.71 - 3.6 V
the VDDA is from 1.71 to 3.6V.
Hope it can help you
BR
XiangJun Rong
Table 12 says for VDD 1.71V .. 3.6V for USB high speed only. According to this, USB would work with 1.8V.
On the other hand, table 21 shows quite contradictory values. Is USB now possible with 1.8V?
