Effect of removing USB 3.0 pins of MC7455


#1

Hi,

For the current project I am using MC7455 series and we ran into the USB 3.0 pins incompatiblity issue. So I have to remove the USB3.0 pins manually. I am not sure whether removing these pins have any effect on the download and upload speed.

I read the specification, its mentioned that


This device has been designed to achieve optimal performance and maximum
throughput using USB superspeed mode (USB 3.0). Although the device may
operate with a high speed host, throughput performance will be on an “as is”
basis and needs to be characterized by the OEM.

I looked into another series of sierra MC7304 which doesn’t support USB3.0 . It looks good fit for my project though it supports lesser LTE bands than MC7455.

If the LTE speed of MC7455 is affected by removing USB 3.0 pins, which I assume so. I feel its better to move to MC7304. May I know your view on removal of USB 3.0 pins and effect on LTE speed.

Thanks & Regards,
vinoth


#2

Vinoth,

USB 3.0 has been added to the MC74 because the USB2 link was beginning to become the limiting factor in conducted testing when using maximum resources, this is unlikely to happen in the real world so most applications will not notice the fact that they have a USB 2.0 link over a 3.0 one, plus if you are transferring data at those speeds for any length of time you are going to need to have a serious data plan.

Regards

Matt


#3

If you don’t use USB 3.0, only USB 2.0 will be used. Seeing that you have problems with detection, your host would need to support USB 3.0 via mpcie. Tapping is enough, no need for physcial removal of the pins.