Tiva Launch pad gets heated

Hi Sai,

     I don't have a Tiva Launchpad. I think it is normal for a microcontroller to heat up a bit when running. If the heat is unbearable, then there might be a problem. 

    It would be helpful, if you are able to compare this "IC heating problem" to another Tiva Launchpad. 

-kel

sai surya teja said:

Can someone explain this strange behavior. Is there anything that i can do to stop the controller getting heated.

 Again can someone explain me how to get the winner of a lottery???

 Which power supply do you use and where you are connecting to?

 What is connected to launchpad?

 How you measured 400mA?

what is hot?

Markel Robregado said:

     I don't have a Tiva Launchpad. I think it is normal for a microcontroller to heat up a bit when running. If the heat is unbearable, then there might be a problem. 

    It would be helpful, if you are able to compare this "IC heating problem" to another Tiva Launchpad. 

 Hi Kel, mine is cold and current drain is in the order of few tens mAmp too.

 The worst condition are the two shorted pin by R9-R10 zero Ohm, when both port are enabled some fight might occour but again current drain is not so high... It is time to remove this threat from that board...

Hi Roberto,

I have used micro USB provided on the launchpad to give the supply.

No other hardware is connected to launchpad.

400mA regulator is mentioned in

'Tiva™ C Series TM4C123G LaunchPad Evaluation Board user's guide'

Hot = temperature > 50 C (approx)

Thank You 

Hi Sai,

Just because the TIVA device is getting hot does not mean that due to the current draw the Voltage regulator should also be heated.

As per the electrical section on the Current Consumption, the max current for a simple loop in Flash is ~45mA at 25C. Assuming that you run the device with an application that moves up the current to a higher value, then from the regulator perspective it is still a fraction of its maximum rating, and ther emay not be any noticable temperature. Other than do look how the thermal dissipation of the devices are. Some devices have good thermal dissipation which allows them to work at higher current w/o significant temp rise.

Regards

Amit

Hi,

You can determine the current consumption by measuring the voltage between H121-H122 and divide by the value of R34 (0.1ohm) in Launchpad.

Petrei

@Sai,

A heating microcontroller chip with only blinking code running is unusual.

There has been a couple of usb cable related problems for tiva launchpad lately. Just to isolate that the problem is caused within the board, try a different usb cable and see if you still get the same response.

-kel

    

sai surya teja said:

400mA regulator is mentioned in

 Ok, so if what I understood is you never measured current and that is max regulator current, otherwise USB at that rate tend to shut down, try open usb diag and see current drain from receptacle, I suppose is in the range of tens of mAmp.

sai surya teja said:

Hot = temperature > 50 C (approx)

 Which processor, JTAG controller or Target? Again both processor after a while on are both at Tamb. How did you measured temperature?

 Is the room where you are using wet? Are you wearing right clothes? Are they of cotton and shoe antistatic too? Otherwise may be you damaged some port by static discharge.

I may have the same problem with the EK-TM4C1294XL. My problem is intermittent. It goes away if I press the RESET button and re-load my firmware. I have not found a reliable way to reproduce the problem, but any time I do not get the expected debugging log information through the UART, I now have a habit of testing the ARM for heat and quickly resetting the board to avoid damage.

My hypothesis is that the processor has jumped into a while (1); loop, such as the default interrupt handlers for NMI and Fault. I tried rewriting those default handlers to print a message and return, rather than loop forever, but I'm not seeing the output so far. I'm not really sure what is causing this, but I do know that it is possible to run my firmware without it overheating - it's just that when I cycle through many slight iterations of my code (in progress), it sometimes seems to crash and overheat.

Does anyone have any idea of what's going on? Could my hypothesis explain the original poster's problem as well as my own?

Brian

p.s. The heat is abnormal and alarming, not the usual level of heat for a processor that is doing work. Is there any diagnostic in Code Composer Studio that could shed some light on the situation, perhaps by querying the chip via JTAG?

Hello Brian

Are you using USB on the main device?

Regards
Amit

Yes, I'm definitely seeing this when using the USB to power a 300 mA Device. I'm powering the whole LaunchPad from its USB input. I believe that the circuits should be able to handle this, even though that's quite a bit of current.

I've certainly been able to run the board with my current firmware and a 300 mA Device attached without the overheating. I have not determined yet what triggers the overheating.

Note that I also experienced this heating when using only the Ethernet port. However, I may have been running some of the USB example code at that time, but without any USB Device attached. The Ethernet phase of my development was a few months ago, though, so I can't recall what firmware was running when it first got really hot.

Hello Brian,

One potential issue could be an IO Latch on the USB pins. This is a known issue on TM4C129 and requires the use of caps on the USB DP-DM lines.
Another item could be that a large current draw to the external devices may be starving TM4C129 and hence with reduced voltage it may try to draw a larger current as well. Might I suggest using an external power supply.

Regards
Amit

Thank you, Amit.

This does seem like it could be a latch-up problem. I will try to find ways to prevent that.

Are you referring to Errata GPIO#09 ?

That errata is limited to USB0_ID (PB0) and USB0_VBUS (PB1). I am using the TM4C1294 as a USB Host, so perhaps this is less of an issue? It still seems that I should disconnect USB0_VBUS.

If there is another Errata specific to USB_D_P and USB_D_N, particularly with specific recommendations for the capacitance needed, then please elucidate.

I will also test the voltage near the TM4C1294 if the heating occurs again. That should tell whether the current draw is starving the chip.

By the way, I am using the TM4C1294 on the EK-TM4C1294XL. Is this chip very similar to the TM4C129? The Errata seem to be cross linked between the parts, so I'm assuming the family is related.

Hello Brian

Yes, the chip is the same and yes, i am referring to GPIO#09. You can force the USB Controller to be in Host Mode and ensure that the pins are connected to GND or as GPIO inputs.

Regards
Amit

Thank you!

In case anyone is reading this thread who is in a similar situation - forced Host mode with random overheating of the TM4C129x - open up pinout.c in your project and make the following edit:

#ifdef IGNORE_ERRATA_GPIO_09
        ROM_GPIOPinTypeUSBAnalog(GPIO_PORTB_BASE, GPIO_PIN_0 | GPIO_PIN_1);
#else
        ROM_GPIOPinTypeGPIOInput(GPIO_PORTB_BASE, GPIO_PIN_0 | GPIO_PIN_1);
#endif

This will treat PB0 and PB1 as GPIO inputs instead of enabling the USB Analog functions that allow the overheating.

After making the above code changes, I still get an overheated TM4C1294 sometimes. Should it be sufficient to not put those pins in USBAnalog mode? ... or do I need to physically cut the traces on my LaunchPad?

Hello Brian,

Add the capacitor on the bus instead of cutting the trace.

Regards
Amit

Hi Amit,

I faced the similar problem. I was using Ek-TM4C123GXL launchpad from couple of months. Initially it was working fine, meanwhile i noticed some I/O latchup problem (means i was unable to set their values to 1 even in debugger register showed its value is one ). I considered i may have damaged certain pins (specially PB3 n PF4) while testing and avoided using them. But from couple of days i noticed main tm4c123 controller (not debugger one) getting hot while running the program n sometimes it was unbearable hot sometime normal.

Suddenly, I am unable to program/erase it. Controller and voltage regulator becomes very hot when connected with USB cable. I also checked by connecting it with external power source, but same response. I measured the current by removing jumper it is about 520mA.

I am unable to figure out what actually caused this, so that i can be careful while using the new launchpad in future. I think my current launchpad can't be recovered. Please comment what may have caused this damage.

Thanks

Hello Sham,

From the description it sounds as if the device was stressed too much that it has hit a hard failure. Extended latch up conditions like the one which resulted in PF4 and PB3 being unusable may be affecting the reliability of the device.

Regards
Amit

Dear Amit,

I got the new Launchpad TM4C123GXL everything is fine but i noticed the voltage regular is getting heated. I measured the current by removing the jumper given on launchpad its around 28 mA which seems normal. I don't understand why regulator is getting heated with such low current. Even with removed jumber (it means controller is not supplied and current will not flow to the main controller) the regulator is getting heated. So i don't think it is normal it was not the case with my previous launchpad. Can you please rectify what can be the problem.

Thanks

Hi Amit and others,

I am having the same issue with the launchpad, when connecting it to an external power supply it draws up to 500mA (the Current limiter max). I have tried setting both PB0 and PB1 to input and setting device as USB host without improvement. Also erasing the flash didn't work.

Maybe the device is already damaged by the prolonged current consumption, although the firmware and USB device communication both work fine.

Hello Fransisco

If the Flash erase is not working, then most probably, the device is no longer "fine". Did you try to run Unlock Sequence (in case you have changed the erase property)

Regards
Amit