We are moving from 4G to 5G on our iot device. I will be substituting the em7455 for the newer EM9191 for 5G. Is that a good idea? I have a kit that the em7455 fits but the em9191 is longer and does not fit. Digi key sells the Manufacturer Product Number
EM DEV KIT_6001173
But it mentions 4G so I don’t know if the kit will accept the em9191. I have the schematics for the em7455 kit that I used to design our PCB. I think the newer kit takes more power so I would like to get the schematics for the new kit. Which part number do I need for the em9191 kit.
Hi curry-te,
Yes, that is.
You should buy a new dev kit with part number 6001349. It can be used for EM919x/EM7690.
Thanks,
Thanks for the information. Do you know where I can get the kit’s schematics?
Bit of a loaded question to Sierra, is it s a good idea buying a newer more expensive unit? 
if you want to go for 5G then yes its good, pretty mature now as we have sold/deployed alot of them globally now.
In terms of migrating from 7455 yes the current draw can be significantly higher because you are now talking about potentially 100MHz BW’s rather than 20MHz, the only other major difference is the need to control pin 21, PCI_DIS, which controls whether the unit boots in USB or PCI mode. This cannot be controlled by a firmware setting as there are timing requirements on the PCI side for initialisation that are too fast for it to be controlled this way.
The dev kit user guide has the schematics in the back.
Regards
Matt
The Sierra EM9191 states USB 3.1. We are using the Variscite line of processors which states USB 3.0. Will USB3.0 work for the EM9191?
As per the backwards compatibility requirements for USB yes it should be fine. I am using it against my USB Linux and Windows machines. Depends on the performance you want to achieve.
Regards
Matt
I am having issues fitting all my components on my PCB. I noticed that Digikey sells a vertical mount M.2 connector. Would it be a problem to mount the EM9191 module vertically? My previous EM7455 design did not allow me to place any components below the module.
Why does the EM9191 have a UART 2.0 interface if we cannot use it? It is my understanding that we have to use the USB 3.0 lines. I am going through a lot of trouble changing processors to get a USB3.0 interface. I would rather stick to USB2.0 if I could.
Re the connector, technically there is no reason why the unit cannot be mounted vertically if the connector allows it as long as you can handle the heat dissipation.
On the USB interface the unit is specified as USB 3.0 only primarily because the air interface is so much faster, what’s the point of having a 5G unit with all of the additional cost if you then limit yourself from a hardware perspective to a lower speed what’s the point. Having said that I connect to my Windows PC/Linux system with a USB2 cable and it works fine.
Regards
Matt
I am guessing that the module falls back to 4G if the usb2 is used.
Tim
I don’t understand " No bearer selection is independent"
Tim
So I meant that the selection of 3G, 4G, 5G is operates independently of whether the unit is using USB 2, 3 or PCIe. It will always go for the best available and if the hard interface is the limiting factor then so be it.
Regards
Matt