FEDEVEL
Platform forum

Alaeddine , 08-05-2025, 01:28 PM

I'm analyzing the schematic of an eMMC chip and noticed that some pins are labeled with two-letter designators like AA3, AA5
Why are the pins labeled that way instead of single letters? Is this related to the BGA package naming convention or something specific in JEDEC standards?

Robert Feranec , 08-06-2025, 09:48 AM

If chip is big and all single letters are used it continues with AA ... you can see there are letters like W Y .. I guess that chip has many pins.

Alaeddine , 08-07-2025, 09:48 AM

and tha's what i said. but when i saw its datasheet, it doesn't have that much pins.

QDrives , 08-12-2025, 10:52 AM

Then why not also complain about T, R, U, V, W and Y?
What does your footprint have?
Did you pick the right package and not the 100 FBGA? The 100 FBGA has some pad 'off grid'.