I have made a pcb of this circuit and my 12v to 5v voltage regulator is getting too hot and the atmega328p pu is not working properly ,
Please check
Hi, @mayankgangwani
Welcome to the forum.
How much current is going through the 12V to 5V converter?
The converter you are using appears to be a linear voltage regulator, these are not very efficient and will get hot if the current through them is too high.
Have you got a heatsink on the regulator?
Did you have this problem when you prototyped it?
Can you please post jpg EXPORTS of your PCB patterns so we can see your component layout?
How do you mean the 328 is not working properly?
What is the application?
Thanks.. Tom.. 
hi
it works fine for a few seconds but then 328 starts malfunctioning
i combined driver and 328 ckt. , it was not a problem when i did it with arduino uno and l298n driver by shorting their inputs and outputs as shown in the pcb ckt. but this fabricated pcb has problems
You didn't answer all the questions, please go back and read.
Also, since you're asking for a comprehensive review, can we please have more than a fuzzy jpeg to work with?
The layout is an even smaller image, not useful at all.
i am not sure about the current, i thought that if prototyping with the readily available parts went good , i could use the same parts.
application is driving 1 775 dc motor from l298n( shortes out4-1 and out2-3 for greater power) and another 5v small dc motor from h bridge from transistors using pins of atmega328 .
Heat sink tab is connected to 5v output , as mentioned in datasheet https://datasheet.lcsc.com/lcsc/1809200041_onsemi-NCP1117ST50T3G--_C17314.pdf
I did not have a problem when i connected uno and l298n and modified them according to this circuit
how should i post the image of pcb layout
Higher resolution. Both images..
That was not the question. It was about the physical connection of traces and pads. Does the IC tab have a large "pour" or area, thermally connected to draw heat away from it?
Or is there an external heat sink, additional part?
If you had posted a readable layout I wouldn't have to ask...
Do you have any ground plane, or ground pour?
That is no change, same as the first one you posted... oh sorry, that is better.
sorry but this is the best ss i could manage , NCP1117ST50T3G onsemi | C17314 - LCSC Electronics
this is the link of regulator used
Now the layout, please...
already posted
Oh, a forum software delay... thanks.
U3 looks pretty "bare" in place... can you please answer my questions about the heat sink? Fully, not just a passing comment?
You chose the SOT223 package, it looks like you have almost no heatsink area on your layout.
Hi,
The capacitors associated with U3, should be as close to U3 as possible.
C3 and C16 and C17 are too far away from U3, they are to bypass and enhance stability of the regulator as well as frequency compensation.
Have you measured the 5V when the regulator gets hot?
Use your DMM to measure the current going in at 12V?
Then calculate the power being dissipated in U3.
Thanks.. Tom...
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the voltages seem fine , at 11.60 input voltage, the Vin and gnd voltage is 10.16v and output gnd is 4.93v
ok noted , what could be the solution now that i have made the pcb
Look at page 8 of the data sheet to learn how to provide a heat sink.
https://www.farnell.com/datasheets/2236912.pdf
Throw it away and do your research next time. Figure 21.