Power Connection to unused block

[deepaknaiknavar]

Hi,

I am using LS1021 processor. This Processor has several blocks and its invidual supply rails like USB, Serdes, GPIO.

I have a basic question- If i am not using a USB block in my applixation, should i connect it to a power rail or leave it unconnected?

What is a better approach?

Thanks,

Deepak

[Pavel]

Look at the LS1021a Design Checklist:

https://www.nxp.com/webapp/Download?colCode=AN4878&location=null&fasp=1&WT_TYPE=Application%20Notes&...

This document contains recommendation for the LS1021a pins connection if USB block or SERDES or GPIO are not used.

Have a great day,
Pavel Chubakov

[alexander_yakov]

Typically, this information is explicitly specified in device datasheet. If it is not explicitly allowed to power down any particular power voltage rail, than this means this voltage rail must be powered even if this functionality is not used.