topic Re: LPC546xx with 1.8V design and USB in LPC Microcontrollers

LPC546xx with 1.8V design and USB

RU — Thu, 14 Jul 2022 14:11:26 GMT

I want to start a LPC546xx design with 1.8V - how can i use USB0?

xiangjun_rong — Fri, 15 Jul 2022 02:27:10 GMT

Hi,

First of all, pls download the data sheet of LPC546xx from the link:

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

XiangJun Rong

RU — Fri, 05 Aug 2022 11:48:26 GMT

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?

xiangjun_rong — Fri, 12 Aug 2022 09:25:30 GMT

Hi,

I think it is correct:

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

Hope it can help you

XiangJun Rong