Layout Peer Review - SMPS

Community PCB Design
1

Afternoon everyone,

I’m new to this form. Well, new to posting. I have been reading for some time now.

Instead of tackling my entire project at one time, I am creating the layout and BOM for different functional blocks.

Please post your thoughts.

[[u]Schematic[/u]

[[u]Layout[/u]

BOM

C14

0.01uF, X7R, 10%, 50V, Ceramic

06035C103KAT2A (Mouser)

C15

4.7uF, X7R, 10%, 50V, Ceramic

81-GRM32R71H475KA88L (Mouser)

C16

4.7uF, X7R, 10%, 50V, Ceramic

81-GRM32R71H475KA88L (Mouser)

C17

220uF, 10%, 10V, Tantalum

B45197A2227K509 (Digikey)

D2

Schottiy, 40V, 3A

621-B340A-F (Mouser)

R8

1/10W, 10k, 1%, ThickFilm

71-CRCW0603-10K-E3 (Mouser)

R9

1/10W, 3.24k, 1%, ThickFilm

71-CRCW0603-3.24K-E3 (Mouser)

L2

22uH, 3.6A, 50mOhm, Power Inductor

MSS1278-223MLB (Coilcraft)

U$4

TPS5430

Sample from TI

Thanks

2

Greetings Joseph,

MrPotatoHead:
Instead of tackling my entire project at one time, I am creating the layout and BOM for different functional blocks.

Looks like you are using EAGLE? If so, can you

post the *.sch and *.brd files?

With live files instead of a snapshot it will be easier

to review your design (which looks good by the way).

Comments Welcome!

3

Substantial ground planes are needed for switching regulators, to avoid EMC problems. Manufacturers usually have detailed application notes on PCB design for their chips.

Leon

4

bigglez:
Looks like you are using EAGLE? If so, can you

post the *.sch and *.brd files?

Yup, Eagle it is. How do I post a file?

leon_heller:
Substantial ground planes are needed for switching regulators, to avoid EMC problems.

The entire bottom and a big chunk of the top are ground planes. Vin and Vout are planes also.

leon_heller:
Manufacturers usually have detailed application notes on PCB design for their chips.

The layout is basically a slight modification of the EVM board layout.
5

I don’t think this board allows posting files, but many websites let you upload files. I’ve seen people use Google Pages here to host their Eagle files before.

It may be worth hitting the “ratsnest” button before making the image of the PCB, it fills in the polygons (your ground planes) so it’s obvious where they are and that they exist.

6

I just added the ability to store and share design files (particularly gerbers) on CircuitPeople.com. You’ll need to register before you can share the design, but once you do you’ll see the “share” button below the images of the gerbers.

Let me know if it sucks, please.

7

MrPotatoHead, (that just doesn’t sound right…)

Next time you export an image of a board, hit ratsnest so that the polygons will get filled.

I don’t know if it will matter but I’d rotate the chip to the left and the inductor to the right to reduce the distance between the inductor and PH pin. If that is the reference layout though, never mind…