Help! Why my AT90USB162 heats up when power is applied?

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Hi,

I have been trying to wire up the AT90USB162, but I have had no luck, because the AT90USB162 heats up when I apply power. Yes, I have searched the web and saw examples of wiring up the AT90USB162, such as the Teensy. But I would like know why my wiring is causing the micro-controller to heat up. Please advice or point out anything I have done wrong or missed.

Please see the attached schematic.

Thanks!

Attachment(s): 

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Doesn't USB use 3.3V? Feeding +5V regulated into a +3.3v circuit might be the cause. Aside from that, I don't see any issues.

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Simonetta wrote:
Doesn't USB use 3.3V? Feeding +5V regulated into a +3.3v circuit might be the cause. Aside from that, I don't see any issues.

Hi,

USB uses 5V with max 500mA output for USB 2.0. And it's pretty stable 5V supply from the computer.

I did think about that, but the AT90USB162, according to the datasheet, can take up to 5.5V. The Teensy, for example, uses 5V.

Interesting, I switched to 3.3V and it does a take a while to heat up.

Plus Atmel's Flex can't see my AT90USB162. :!:

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If I didn't know any better, I would suspect that the power is reversed to the chip, in which case they always get hot and the programmer never wants to talk to the chip. I note that MCU's often work quite OK after that but .....who knows!
Since power is proportional to square of the voltage, it will take 2.5 times longer to get just as hot at 3.3 V than 5 V.

Charles Darwin, Lord Kelvin & Murphy are always lurking about!
Lee -.-
Riddle me this...How did the serpent move around before the fall?

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LDEVRIES wrote:
If I didn't know any better, I would suspect that the power is reversed to the chip, in which case they always get hot and the programmer never wants to talk to the chip. I note that MCU's often work quite OK after that but .....who knows!
Since power is proportional to square of the voltage, it will take 2.5 times longer to get just as hot at 3.3 V than 5 V.

I double checked and double checked that all the power wires are not reversed. The AT90USB162 is soldered to the TQFP-PDIP adapter and the pins are correctly lined up.

Oh, well...Either more coffee or more sleep. Until then...

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I suspect there is a pin number counting problem (wrong chip key orientation, wrong USB connector pin numbering etc.)

Warning: Grumpy Old Chuff. Reading this post may severely damage your mental health.

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Another possibility: Solder bridge / short.

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JohanEkdahl wrote:
Another possibility: Solder bridge / short.

Checked all of the below:

1. Chip orientation is correct. Upper-left corner with the dot of the chip is aligned to pin 1.

2. I double-checked a numerous times under the soldering microscope to make sure that there is no shorts. But, I think having a buddy to look over under the microscope would also help.

I have done this with the ATMEGA8/168 TQFP-32 pins no problem.

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Quote:
I double-checked a numerous times under the soldering microscope to make sure that there is no shorts. But, I think having a buddy to look over under the microscope would also help.

Maybe use a DVM to check for shorts btw adjacent pins?

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How much current does the whole board draw?
How much should it draw?
What is the supply voltage?
What should it be?
The MCU is either sourcing or sinking a lot of current!
I note that if USB connector schematic layout not the same as the physical layout of the connector. Transposition?

Tip: While you are working on this fault, power the USB device under test from a powered USB hub. Blowing up a USB power driver in a PC/Notebook is not nice. They are suppose to be current limited, but I have seen the limiting not work!

Attachment(s): 

Charles Darwin, Lord Kelvin & Murphy are always lurking about!
Lee -.-
Riddle me this...How did the serpent move around before the fall?

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LDEVRIES wrote:
How much current does the whole board draw?
How much should it draw?
What is the supply voltage?
What should it be?
The MCU is either sourcing or sinking a lot of current!
I note that if USB connector schematic layout not the same as the physical layout of the connector. Transposition?

Tip: While you are working on this fault, power the USB device under test from a powered USB hub. Blowing up a USB power driver in a PC/Notebook is not nice. They are suppose to be current limited, but I have seen the limiting not work!

LDEVRIES@: Thanks for the response. Obviously, the AT90USB192 is drawing too much, thus, the heat. I can't tell how much it's drawing, but it should be drawing no more than what's the spec says. Note I have not given it any work/load, that is, do stuff, as per the schematic.

That's very good that you noticed the schematic layout of the USB part (pin wise) is not exactly like the physical connector itself. Don't worry the pins are correct. That EagleCAD USB part is from Sparkfun.com, by the way.

I actually use a USB power dongle (if you will) to power the USB. That dongle is as specified by the schematic, and I have been using that dongle, and it's fine. I tested with the ATMEGA8, with some simple LEDs, with my homebrewed ASPUSB programmer board, etc.

Thanks, all, again for all your comments.

Last Edited: Mon. Nov 22, 2010 - 04:56 AM
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Has the uC been programmed before?
I assume Switch 2 is open, and PortD.7 is an input.
It it was an output, high, shorted to ground via the switch, you would also have problems.

JC

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DocJC wrote:
Has the uC been programmed before?
I assume Switch 2 is open, and PortD.7 is an input.
It it was an output, high, shorted to ground via the switch, you would also have problems.

JC

This is interesting response...No, the uC is brand new. In fact, I don't want to program it now, because to test out that the built-in bootloader to work with Flex. Yeah, according info from the net and Atmel, both the switches are input and are open and active low.

I don't quite understand what you are hinting at, but, having working on projects with buttons before, the switches should be fine, and they are turned on when pressed causing a logical zero.

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I am out of ideas, other than you have the probes connected to your multimeter correctly haven't you?
What is the reason you can't measure the currents & voltages. They are key values to get a handle on this problem.
Perhaps put a 100 resistor in line with Vcc from the USB connector % measure voltage drop across it. I would be most surprised if you don't measure 5V.

Charles Darwin, Lord Kelvin & Murphy are always lurking about!
Lee -.-
Riddle me this...How did the serpent move around before the fall?

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Herewith my 2 cents.

If you do not want to re-program the uP, can you at least read the fuse bits? If not I would think it is a layout issue as previously suggested.

I notice you have AVCC connected to +5V. Is your ADC reference (REFS1 and REFS0 in ADMUX) setup correctly? If not then the uP might draw a lot of current.

Have you tried removing +5V from UVCC to see if the current consumption goes down?

Do you have a second uP to try? If the uP was damaged because of the excessive current drawn, you might fix the issue, but the uP being damaged still draws more current that it should.

There is a special place in Hell reserved for engineers whose code works the first time.

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ettienne wrote:
Herewith my 2 cents.

If you do not want to re-program the uP, can you at least read the fuse bits? If not I would think it is a layout issue as previously suggested.

I notice you have AVCC connected to +5V. Is your ADC reference (REFS1 and REFS0 in ADMUX) setup correctly? If not then the uP might draw a lot of current.

Have you tried removing +5V from UVCC to see if the current consumption goes down?

Do you have a second uP to try? If the uP was damaged because of the excessive current drawn, you might fix the issue, but the uP being damaged still draws more current that it should.

Removing the UVCC does indeed NOT causing the uC to overheat! :o Uhmm...Interesting. All the schematics on the AT90USB162 that I know of (Teensy and Olimex's) do have the UVCC connected to 5V.

But cant read the fuse bits with OR without the UVCC connected to 5V. I tried many times. I have another uC but no more to-PDIP adapter board. Ordered some. I guess the truth comes when put in the new uC WITHOUT the UVCC connected. A good chance the uC might have been blown previously.

The datasheet shows that the UVCC is fed into an internal 3.3V regulator and the output goes out to the UCAP pin that is connected to the 1uF IN PARALLEL to GND. See Figure 2.1 of the datasheet. BUT, Figures 7-1 and 7-2 show the UVCC CAN be connected to a 5V and the UCAP is connected to the 1uF in series!

Figure 19-3 is like what my schematic is. (See my original post for the schematic image.) That is: UCAP in series with the 1uF and VCC and UVCC are connected to 5V.

Throwing both hands in the air.

c:\AVR\projects\fuses>avrdude -p usb162 -c usbasp -u -U lfuse:r:lfuse.txt:h -U hfuse:r:hfuse.txt:h -F

avrdude: error: programm enable: target doesn't answer. 1
avrdude: initialization failed, rc=-1
avrdude: AVR device initialized and ready to accept instructions
avrdude: Device signature = 0x000000
avrdude: Yikes!  Invalid device signature.
avrdude: Expected signature for AT90USB162 is 1E 94 82

avrdude done.  Thank you.

Thanks!

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I have 2 90USB1287 sitting on my desk and they have all Vcc interconnected as your schematic shows.
And a 1µF cap connected from UCAP to GND.
I see no problem with that.

OTOH my chips are in Host mode and thus sending out 5v through USB connector, not having power supplied from a Host.

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Lennart wrote:
I have 2 90USB1287 sitting on my desk and they have all Vcc interconnected as your schematic shows.
And a 1µF cap connected from UCAP to GND.
I see no problem with that.

OTOH my chips are in Host mode and thus sending out 5v through USB connector, not having power supplied from a Host.

I give up with Atmel's uCs with USB support. The whole damn datasheet does not even show one complete schematic of a typical app! :evil: It's time to move to another uC with USB.

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Quote:
I give up with Atmel's uCs with USB support. The whole damn datasheet does not even show one complete schematic of a typical app!

None of the data sheets show how to do a Blinky or interface a switch either.That is not thr purpose of the data sheets.
Application notes should show that sort of detail ATMEL have application notes on USB and they use the STK525 for their demo platform. So go to AVR tools in AVRStudio, dial up STK525 & select schematics and you have hardware examples.
Or the AT90USBkey http://www.atmel.com/dyn/resources/prod_documents/doc7627.pdf

All the development systems can be reverse engineered this way to get hardware interfacing ideas.

So...don't throw the baby out with the bathwater yet!

As far as software goes, look to LUFA!

PS. Make sure that Ucap is not shorted to ground or that a tantalum/electro cap has been put in reverse. That would cause overheating!
(If you think I am telling Grannies how to suck eggs, thats because I don't know which grannies have sucked an egg!)

Charles Darwin, Lord Kelvin & Murphy are always lurking about!
Lee -.-
Riddle me this...How did the serpent move around before the fall?

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LDEVRIES wrote:
Quote:

Application notes should show that sort of detail ATMEL have application notes on USB and they use the STK525 for their demo platform. So go to AVR tools in AVRStudio, dial up STK525 & select schematics and you have hardware examples.
Or the AT90USBkey http://www.atmel.com/dyn/resources/prod_documents/doc7627.pdf

That's the problem. Most of Atmel's appnotes refer to their costly dev tool products. They dont do a very simple schematic of a product.

Quote:

So...don't throw the baby out with the bathwater yet!

As far as software goes, look to LUFA!

Yeah, I know of LUFA and see a lot of supports and boards made using LUFA.

Quote:

PS. Make sure that Ucap is not shorted to ground

All the figures and schematics I have seen so far have the UCAP pin connected in series to the 1uF to GND.

I'll give it a try and leave it unconnected.

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unebonnevie wrote:
LDEVRIES wrote:
Quote:

Application notes should show that sort of detail ATMEL have application notes on USB and they use the STK525 for their demo platform. So go to AVR tools in AVRStudio, dial up STK525 & select schematics and you have hardware examples.
Or the AT90USBkey http://www.atmel.com/dyn/resources/prod_documents/doc7627.pdf

That's the problem. Most of Atmel's appnotes refer to their costly dev tool products. They dont do a very simple schematic of a product.

Quote:

So...don't throw the baby out with the bathwater yet!

As far as software goes, look to LUFA!

Yeah, I know of LUFA and see a lot of supports and boards made using LUFA.

Quote:

PS. Make sure that Ucap is not shorted to ground

All the figures and schematics I have seen so far have the UCAP pin connected in series to the 1uF to GND.

I'll give it a try and leave it unconnected.

EUREKA!!!!!!

The problem was the 1uF UCAP should be connected parallel to the pin, which is connected to VCC. The 1uF connected in parallel to GND.

BAM! It works! NO OVERHEATING! The uC is as "Cool Hand Luke" operating at 5V. As soon as I plugin, using my USB dongle, WINDOWS Vista detected new USB hardware and installed the Flip drivers!

See attached images, which include the updated schematic.

Atmel Flip works fine, able to read fuse bits, etc.

And the overheated (repeatedly) uC still survives!

Thank you, all! Imagine just one connection! :D :D :D X 1000

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So you figured out removing UVCC does not cause overheat. This pin is only used for 3.3V LDO. You do not need to use it, so simply leave USB and LDO disconnected for now. Try ISP, write some code to test IO pins.

No RSTDISBL, no fun!

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Quote:
All the figures and schematics I have seen so far have the UCAP pin connected in series to the 1uF to GND.

And that is the way that it should be, but with a blob of solder acceoss both pins of the cap, it will be grounded.
Quote:
That's the problem. Most of Atmel's appnotes refer to their costly dev tool products. They dont do a very simple schematic of a product.

But they provide very good documentation, which is free and you can copy to your hearts content.

Charles Darwin, Lord Kelvin & Murphy are always lurking about!
Lee -.-
Riddle me this...How did the serpent move around before the fall?

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unebonnevie wrote:

The problem was the 1uF UCAP should be connected parallel to the pin, which is connected to VCC. The 1uF connected in parallel to GND.

Tiny mistake on the above. The "connected to VCC" should be Vout 3.3V. So, for folks who want to use the posted schematic, please make note of this.

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ok, one tiny problem: I can't still read the fuse bits of the AT90USB with my USBASP programmer.

I read on the net and avrfreaks.net that Atmel shipped this uC with the lock bits set, thus, not able to read anything off the uC.

So, I thought I would try to read the fuses bits and from there turn off the lock bit, but I can't read the fuse bits.

My AVRDude keeps saying the below. ATMEL's Flip recognizes the device without any problem, including displaying the correct device id.

Tips?

c:\AVR\projects\fuses>avrdude -p usb162 -c usbasp -u -U lfuse:r:lfuse.txt:h -U hfuse:r:hfuse.txt:h -F

avrdude: error: programm enable: target doesn't answer. 1
avrdude: initialization failed, rc=-1
avrdude: AVR device initialized and ready to accept instructions
avrdude: Device signature = 0x000000
avrdude: Yikes!  Invalid device signature.
avrdude: Expected signature for AT90USB162 is 1E 94 82

avrdude done.  Thank you. 
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unebonnevie wrote:
ok, one tiny problem: I can't still read the fuse bits of the AT90USB with my USBASP programmer.

I read on the net and avrfreaks.net that Atmel shipped this uC with the lock bits set, thus, not able to read anything off the uC.

So, I thought I would try to read the fuses bits and from there turn off the lock bit, but I can't read the fuse bits.

Found the below answer.

http://groups.google.com/group/d...

1. I need to erase the chip
2. Disable/reset the lock bits
3. Install back Atmel's bootloader or one of my choice, e.g., LUFA