Tagged Questions
8
votes
1answer
189 views
Is there a PCB-layout related reasoning behind DDR memory package and footprint?
BGA DDR packages have a unique footprint. There are two columns of pads on both sides of the device, and an empty column in between.
Is there a reasoning behind the placement of these pads (in ...
5
votes
1answer
229 views
How good is my xtal design on my pcb?
I'm designing a board for a school project using eagle. I thought I could get away with using the onboard clock of the PIC18 since it's not doing a whole lot (mostly just LEDs), but one of its tasks ...
1
vote
2answers
249 views
How is it possible to make Eagle parts containing multiple components?
Is there any way to achieve the following (or something equally helpful) in Eagle?
I would like to create a library Part that itself consists of multiple components pre-connected and pre-routed (by ...
1
vote
2answers
133 views
Ground copper pour for Crystals and Real time clocks
I am laying out a (2-layer) board, with a standard SMD Crystal as well as a Real-time clock placed on the top-side of the board.
What are guidelines regarding ground copper pour under the Crystal and ...
4
votes
1answer
657 views
How critical is the layout of USB data lines / how does my layout look?
I'm laying out the USB data lines on my board at the moment, and I'm just trying to get an idea of how well off my design is gonna fare. Here are the particulars:
4 layer board (from the top: ...
6
votes
1answer
358 views
How is my crystal layout looking?
I've done a preliminary layout of my crystals. I've never designed a board with crystals so this is just a rough first pass based on my small set of working knowledge of crystal layout. How am I ...
10
votes
2answers
468 views
Mixed signal PCB layout for PSoC
I am developing a PCB for an analogue sensing application. It uses the internal ADC on a PSoC3. As usual, the application is very space constrained (11mm x 21mm), so I have had to make some ...
2
votes
2answers
243 views
Questions About PCBs
I understand what they are but i have a few questions...
What are the multi layers on a pcb (i understand 1 and 2 is front back but what about 3, 4 ,5 etc.)
In ...
4
votes
3answers
1k views
Blind/buried vs. through hole vias?
I'm trying to learn PCB design and, from what I've read and seen, there appear to be three different types of vias:
Through hole - goes all the way through the board
Blind - goes from the top or ...
4
votes
5answers
925 views
Can a trace connect to a pad on the top layer?
I'm making my first two layer PCB and have am unsure of whether it's ok to connect a trace to a pad on the top layer (if the pad is on the bottom layer, that is). Here's a picture to show what I'm ...
6
votes
3answers
643 views
Want my PCB design to work right the first time!
Just finished a design of a 8-Layer PCB, the highest frequency is 125MHz.
I want this design to work right the first time, how should I revise the design and what should I take care of?
Something ...
13
votes
4answers
1k views
Standard PCB Layout Book
Are there any good references on advanced PCB design/layout/routing? There seems to be a large wealth of circuit design books, books about RF PCB design, and books dealing with high-speed digital ...
1
vote
1answer
363 views
Criticize SMPS PCB Design
Yes, it is me again with a PCB Design. I am learning a lot thanks to you. This time, the specs are;
10-32 V input
35V 4A output
Boost converter
The controller IC is LM3478.
Schematic & PCB:
...
2
votes
3answers
307 views
Guidelines on branching of a PCI express signal
We have 3 PCIe slots on a board, let's call them A, B and C. On this board, slot A will always be populated with a PCIe device, however, among slots B and C, only one of them will be populated.
There ...
1
vote
1answer
673 views
SMPS PCB Design Critic 3
Can you critique my design?
After finishing my 5v part, I've added the 35V part, too.
10-32V to 5V 1.2A SMPS Buck Regulator, the IC is IFX91041 from Infineon.
10-32V to 35V 4A SMPS Boost ...
1
vote
1answer
333 views
SMPS PCB Design Critic 2
Thanks for your patient help, I am learning a lot. This is my (final, I hope) re-designed layout. What do you think?
10-32V to 5V 1.2A SMPS Buck Regulator Design.
The IC is IFX91041 from infineon.
...
2
votes
1answer
800 views
How do I look at all the footprints in a KiCAD library?
In the KiCAD PCBnew layout editor,
is there some way to see what a footprint looks like before I place it?
Or am I forced to select a footprint that has a plausible-sounding (ASCII text) name,
place ...
2
votes
2answers
686 views
What are the drawbacks to a Vcc (positive voltage) plane?
I'm familiar with using ground planes when designing circuit boards. I've started used power planes for the predominant voltage in a couple of my designs, and I'm wondering if that's a bad idea. I'm ...
3
votes
3answers
853 views
VCC trace routing on a two-layer board with TQFP chip
I'm just trying to layout a PCB with CY7C68013A (100-pin TQFP) on it. It's a sort of experiment, so I'd like to use 2-layer PCB, 4 layer PCBs are just too expensive. This leads to some interesting ...
10
votes
4answers
844 views
Can I run traces through “No Connection” pins?
Several ICs are manufactured in packages with more pins than it supports. For example, the LM317 in an SO8 package has 4 VOUT pins and 2 N/C (no connection) pins. I often want to run traces through ...
