Atmega chip burns when connected to POWER

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Hello! I'm studying electronic and I tried to make H-bridge motor drive circuit for experience. 

but I got a problem. 

I am not an expert in this field and I am learning.

 

I ordered PCB board twice because of this problem.

Right after I connected the board with STK500 and laptop through the ISP terminal,

Atmega128 chip is suddenly burned !

 

I don't know the exact location where is burning exactly.

I guess VCC and AREF is burned.

 

you can see the picture. 

 

On PCB picture, the thick white line is +5V Power, it 's from 7805. 

I don't know why this hardware problem is happening. 

 

Please help me. Thank you all!

 

 

 

 

 

Attachment(s): 

Hi! AVR

Last Edited: Wed. Feb 12, 2020 - 01:19 PM
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This does seem a bit ambitious for a beginner - what have you done in preparation for this?

 

I ordered PCB board twice because of this problem.

You really need to have proved the design before you commit to PCBs!

 

How did you do that?

 

Your 'circuit.png' just shows the AVR in isolation:

 

That's no help to anyone!

 

You need to post your full schematic!

 

Also post some good, clear, in-focus photos of your setup.

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if "vr1"  on the PCBB picture is supposed to be the LM7805 then you have a small problem if you have put in a TO220 package chip. You seem to have grounded pin1 which is the input of the regulator.

 

But post at least a full schematic such that we can check.

I think you might be glad you did not blow up your STK500 board......

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I'm really sorry if my hurry was uncomfortable.

 

While I redesigned the board, 

I thought the thickness of the pattern is small problem and i changed it from 0.4mm to 0.5mm , but it was useless

 

 

I repost it with full schematic and entire PCB picture .

The picture pcbb is a part which i expected to have a problem. 

 

thank you for replying.

Hi! AVR

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thank you for replying.

 I reposted it with full schematic and entire PCBs.

and "vr1" is T93YA to adjust brightness of letters 

Hi! AVR

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You have not considered the inductance and resistance of many of your tracks. The board needs to be redesigned.

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The Vcc/Ground pins on the micro and the AVcc/Ground pins both need a by-pass cap, 0.1 uF, across them.

This should be mounted as close to the micro's pins as possible.

 

Do NOT connect ARef to Vcc.

As a general rule, ARef should have only a cap to ground.

Again, 0.1 uF, will work fine for this.

 

There are some designs where one might connect the ARef pin to an external voltage reference, but your design does not require that.

Connecting the ARef pin to the Vcc rail can damage the chip if the software tries to assign a different voltage as the reference voltage inside the micro.

 

You might wish to put a 200 ohm resistor in series with the I/O pins and the pushbutton switches.

If the software mistakenly makes a pin an output, and high, while the user is pressing the push button switch, then the switch will short the V+ to ground.

A series resistor will limit the current so that the I/O pin isn't damaged.

 

I rarely see it done, but I usually put a footnote on my schematics that states which I/O pins need to have their internal pull-up resistors enabled.

That way when someone is looking at the schematic and writing code for the board they don't forget to do that.

In your case the four push button switches all need their I/O pins' pull up resistors enabled.

 

JC

 

Edit: typo

Last Edited: Wed. Feb 12, 2020 - 10:18 PM
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The IRF2101 is not the best chip for you...it is rated to 600V, but you don't need that

 

What you DO need is a driver chip that will not allow the high & low side fets to come on at the same time (regardless of the provided logic signal condition)....look for synchronous driver chips...they prevent "shoot-through" in their design...they ensure the controller can never cause such a problem.   Even if your software is completely messed up there will be no damage from shoot through.

 

Forget running the ENTIRE motor board using a 1n4007 1 amp diode....get something beefy....use an MBRD540 diode and live long.

 

Use a higher oreder filer to monitor the cureernt  (RCRC instead of RC...you will be much happier.

 

Your little switches need ESD protection...at least an RC, (minimum) to catch spikes.  There are 100000 nice chips that have diodes and everything ready to use to halt ESD

 

This is a motor board...you need to add a pot or a pot input to an ADC...you will want to turn a knob and see things happen.  You will grow old using buttons for everything.

 

 

When in the dark remember-the future looks brighter than ever.   I look forward to being able to predict the future!

Last Edited: Wed. Feb 12, 2020 - 11:02 PM
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There are plenty of things wrong with the board (as others have mentioned.)  But I don't really see anything obvious that would "burn" the ATmega chip (whatever that means.)  Do you have a photo of a built board?

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Remove the 10uF capacitor on the reset line...... You will never ever be able to program the chip with that mounted.

make it 10nF or something like that or else the programmer will not be able to attach to your chip.

 

and please explain the "burn"  bit as I also do not see anyth9ing wrong with the schematic.

I assume you have triple checked that the processor is mounted correctly so pin1 is at the right location.

 

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As well, having a 1Ohm current sense resistor isn't a good idea - the motor may consume more than the 0.8A you expect and the voltage drop across the resistor will cause the lower mosfets a smaller Vgs value. Mix in some inductance and you have an oscillator. 0.1R or lower might be a much better idea, but you might need to add some gain in order to get a useful reading via the adc.

 

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WHERE are your high current power traces for Q5 (& others)...all that is shown are some signal lines going to the 3 pins!!!  It give the impression you aren't paying attention during your layout.  You probably can use this as a learning, before you start over with a new layout

When in the dark remember-the future looks brighter than ever.   I look forward to being able to predict the future!

Last Edited: Thu. Feb 13, 2020 - 01:34 PM