Shoutout to TI package designers! - Page 1
Forum section: electronics / general

author: Ice-Tea
author_rank: Super Contributor
timestamp: July 12, 2024, 11:03:19 am
content: If you're reading this, I'm sure you've had some seriousmoments when looking at some packages and footprints. There are Hall of Shames for those. But how often do you actually encounter works of art that make you go "well, that'll do!"? Not often, right?I present to you the LM73100 Ideal Diode.Those two wonky stripes in the middle? In- and output. This just makes me happy. Surely I can't be the only one?Cherry on top? It's called a "VQFN-HR". And "HR" stands for "HotRod".I am pleased.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: July 13, 2024, 09:23:30 am
content: I was surprised by the pinout of the RP2040.It does not have any GND pads on it's circumference. It "only" has the big GND pad in the bottom center of the package.So that is 4 extra I/O pins for free compared to a more traditional use of the package.Another unconventional part is that I/O pins are all "GPIO" and no division over ports.This is a weird beast. Dual Cortex M0+ and that I/O structure is probably related to the PIO state machines, which can do quite fast specialized IO things.

author: Uky
author_rank: Regular Contributor
timestamp: July 13, 2024, 03:32:45 pm
content: The "best" packages for a PCB designer are those that have the exposed center slug = GND and a surrounding ring of VCC/VDD etc pins around it.EasyPeasy to decouple on the secondary side of the PCB using copper filled through-hole vias. Fan-out from such packages are really easy.The prize for the worst package I have ever encountered was a BT chip (now long gone) from TI.That BGA chip had the GND and other supply pins spread out all around the package making fan-out nearly impossible, not to mentiontrying to acheive the shortest possible tracks to the decoupling capacitors.For the foot print designers (such as myself), I can see which manufacturers that knows the pain we face and that theypresent the foot print drawing in such a way that the drawing specifies pin pitch, pad dimensions and suggests suitablepad dimensions, specifying _CENTER_ dimensions instead of airgaps.To them: KudosTo all other: Take a PCB design training class and learn how we work.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: July 19, 2024, 02:42:42 pm
content: Perfectly normal and that's not even a very particularly exotic one.

author: Ice-Tea
author_rank: Super Contributor
timestamp: July 20, 2024, 11:31:10 am
content: You know many packages calledHotRodthen?

author: tszaboo
author_rank: Super Contributor
timestamp: July 20, 2024, 12:04:22 pm
content: Quote from: Uky on July 13, 2024, 03:32:45 pmUnless you want single sided assembly. I wanted to make a layout for the RP2040 using 0402 or bigger parts. Nope, I hate it.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: July 20, 2024, 01:58:05 pm
content: Quote from: tszaboo on July 20, 2024, 12:04:22 pmIsn't that the other way around? Center slug as GND is perfectly all right if you put the decoupling capacitors on the backside. If you only want footprints on one side, then GND and Vcc pins. On a dual layer (2 copper layers) having GND pads in addition to the center GND is convenient to break out routing to the GND pad, but for 4 or more layers and a continuous GND layer, GND pins in addition to the central pad are not very useful anymore.