What is v1p1 - Page 1
Forum section: electronics / general

author: NickWolfe
author_rank: Contributor
timestamp: February 23, 2019, 12:35:16 pm
content: Hi guys, new forum member, years of eevblog watcher hereSo 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

author: NickWolfe
author_rank: Contributor
timestamp: February 23, 2019, 12:40:59 pm
content: Sorry for the bad quality photo, but thought it'd be good with at least a hint as to what exactly I meant

author: ebastler
author_rank: Super Contributor
timestamp: February 23, 2019, 12:43:40 pm
content: 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.

author: Twoflower
author_rank: Frequent Contributor
timestamp: February 23, 2019, 12:48:08 pm
content: 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.

author: NickWolfe
author_rank: Contributor
timestamp: February 23, 2019, 02:21:04 pm
content: 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!

author: NickWolfe
author_rank: Contributor
timestamp: February 23, 2019, 02:22:58 pm
content: Choosing a highspeed bga as a first project might not have been the smartest choicebut this can change the future of gaming, so...

author: NickWolfe
author_rank: Contributor
timestamp: February 23, 2019, 02:24:43 pm
content: 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

author: Doctorandus_P
author_rank: Super Contributor
timestamp: February 23, 2019, 04:20:27 pm
content: 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.

author: NickWolfe
author_rank: Contributor
timestamp: February 23, 2019, 04:28:12 pm
content: 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* XDSendt fra min SM-G930F med Tapatalk

author: NickWolfe
author_rank: Contributor
timestamp: February 23, 2019, 05:20:49 pm
content: Bingo! Found this referenced to the vxpx question.Thanks for all your help!Sendt fra min SM-G930F med Tapatalk

author: asmi
author_rank: Super Contributor
timestamp: February 26, 2019, 02:18:26 pm
content: 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).