EEVblog Electronics Community Forum
Electronics => PCB/EDA/CAD => Topic started by: NickWolfe on February 23, 2019, 12:35:16 pm
-
Hi guys, new forum member, years of eevblog watcher here
So I'm about to design my first pcb, and in the reference I am seeing labels such as v1p1, v1p3, v3p3 that runs out to nothing (unconnected) what might this mean? I have spent the last two days searching for an answer to no luck.
Thanks in advance!
Nick
-
Sorry for the bad quality photo, but thought it'd be good with at least a hint as to what exactly I meant
-
I guess V1P2 means "Voltage 1.2", V3P3 is "Voltage 3.3" etc..
You should see a source for these voltages somewhere on the schematic.
-
I agree with ebastler.
But you should find the source of this. Somewhere in the schematics should be the other end if this signal/supply. It is just a label to simplify the schematics otherwise you have to draw everything on one page and have a lot of lines running across. This could also be on a different page.
-
Looking at this, it makes sense, I didn't bring a reference sheet with me, only datasheets. Tried my best to frame what I meant in the picture.
Also thanks a ton for the swift responses!
-
Choosing a highspeed bga as a first project might not have been the smartest choice :palm: but this can change the future of gaming, so... ;D
-
Quickly, if there's an experienced fellow that can set aside som time in private for some help or guidance, I'll make it worth your time
-
ebastler is probably right, but engineerd do not trust "probably"
But the solution is simple:
V3P3 is a label. and labels with the same name are connected together.
The circuit looks like a power supply, (Engineers, don't trust "looks like", but they can take a hint).
So to be sure, just search for all other labels with the name V3P3.
-
Yeah, after trawling through a ton of pages in two different datasheets, that gives the most sense. Let's see how bad it blows up when fabricated. (it's a damn $30 chip)
And yeah, the schematic is for the power delivery part of it, the chip is split in to 3 seperate parts in the schematic just to confuse me even more, and this is the power part.
Shivering just thinking about the headaches awaiting when I have to lay it out, with differential pairs, matched impedance and all that across 6 layers *fml* XD
Sendt fra min SM-G930F med Tapatalk
-
Bingo! Found this referenced to the vxpx question.
Thanks for all your help! (https://uploads.tapatalk-cdn.com/20190223/a407fa8d02160698713c0ca4b9c24dbb.jpg)
Sendt fra min SM-G930F med Tapatalk
-
I always mark my power rails like +1V0 (1.0 V), +1V8 (1.8 V), or add some specifier if there are multiple rails with the same voltage (like +1V8_A for "quiet" 1.8V rail for analog devices).