Guys i’m just an amateur at PCB designing, asked someone to design a board for me for the IC "AAT3673"http://analogictech.com/products/produc … hp?PID=297
He designed a board, can someone check this please? It’s like an better alternative to the Lipo Charger Sparkfun has.
Also, can someone tell me in layman terms what ENO, EN, and ENBAT are for?
Thanks so much.
Those signals are described in the data sheet on page 2!
It also helps if you mention what software the PCB design is in, and provide either images, PDFs, or gerbers of the layout as not everyone has “Software X” installed.
The software used was Protel 99SE. I’ve put a pic below. Whoever designed it should read the datasheet, pages 23-24 in particular. I would suggest following the reference design on page 24:
High current traces should be much wider.
A bunch of vias should be used to connect the “paddle” on the bottom of the chip to the groundplane, for thermal reasons.
A few other observations:
The input power connector has holes the same diameter as the pads. Pads need to have a minimum “annular ring” size.
Vias connecting to planes should not normally have thermal reliefs - there is no need for them, and in the case of the vias that should be underneath the chip, thermal reliefs would negate their main purpose (ie to remove heat).
Not sure why the connectors have the signals doubled-up like that. Normally a battery connector would have one ground pin and one pin for battery voltage.
Depending on the power input used, additional overvoltage protection may be advisable.
In addition to what was mentioned above, there’s a silkscreen dot under the U1 package that will likely interfere with soldering the paddle.
/mike
I don’t know if the silk screen pattern hanging out of the board edge will bother your board company or not. Using BatchPCB I would suspect it might increase the calculated price.
I expect that those capacitor pads are that way to accommodate two different sizes of caps. I would try to leave a bigger gap there myself to accommodate my marginal hand soldering.
I don’t see a problem with the U1 dots.
The traces that go respectively from C1, R3, and C2 to OUT, BAT, and TS connector pads seem to be shorted between the connector pads.
I agree that the oval pads on P2 should be bigger in their small dimension to leave copper around the holes.
I prefer leaving a 0.020 or more spacing on my geometric copper pours in a low-speed low-frequency design, but your narrower spacing should work fine. I am in the minority on this one I presume.
I would try to increase the font character spacing on the component designations a tad, if it is easy to do. Your P8 silk label seems particularly compressed. If you want to save space, you could use a smaller font for those. A 4 font size would be very readable to somebody already doing close work.
Guys I really appreciate the help, I will tell him to make the changes, or I’ll wait until my exams are over and learn Electronics and change it myself.
Just out of curiosity though, if I ask someone to make exactly what I sent you guys, would it work?
My initial motive was to make a Mighty Minty Boost http://www.instructables.com/id/How-to- … aka-Might/, which has a 6Ah battery http://www.sparkfun.com/commerce/produc … ts_id=8484.
I found that the sparkfun charger http://www.sparkfun.com/commerce/produc … cts_id=726 took too much time to charge fully. So I found this alternative. Will it work the way I want it to? Just like Mighty Minty Boost?
Again, I really appreciate it, I see you guys really put your efforts into the replys and I am so glad. 
Can you just use this MCP73833 charger from adafruit:
Just out of curiosity though, if I ask someone to make exactly what I sent you guys, would it work?
If your project title is “How to make a LIPO battery Catch Fire” then yes this design will work nicely for you.
Assuming you are using a single cell Lipo battery with a standard 2 pin JST connector and plug it into the BAT connector then you have just shorted the battery terminals together. The battery probably won’t actually catch fire because it should have short circuit protection built in, but if it doesn’t then you might want to have a fire extinguisher handy.
Wayne
