USB superspeed peripherals Forum Discussions

[PraveenAmara]

Hi Team

We are facing a thermal issue in our FX3 design. 

Due to the board's small form factor, The IC is getting heated up to ~60deg. 

As of now, we are powering an FX3 I/O with 3.3V. ( Overall FX3 power supply is 3.3V).

My doubt is if we reduce the power supply from 3.3V to 1.8V of FX3. Whether this change will help to reduce the temperature on the board? 

[Rashi_Vatsa]

Hello,

Please refer to this thread with a similar query  Solved: CYUSB3014-BZXI - over heating issues - Infineon Developer Community  

[PraveenAmara]

Hi Rashi_Vatsa

Thanks for your reply. 

I checked that. But my doubt is specific. 

If we reduce the operating voltage of the Fx3, Is it improve a thermal issue? 

[Rashi_Vatsa]

Hi,

Can you please let me know which component on the PCB is causing the PCB to heat up? This will help us to understand what exactly is causing the thermal issue.

Also, please let me know when is the thermal issue seen. Is the device programmed with firmware or in USB boot i.e. Bootloader mode? The reason for this question is which all blocks of FX3 are enabled when the issue is seen as the FX3 core and U3TXVDDQ/U3RXVDDQ works  with 1.2V 

Please let me know the CVDDQ voltage 

[PraveenAmara]

Hi Rashi_Vatsa

FX3 is getting heat. 

The device is programmed with the example code USB bulk code. 

I can see the image running on the screen. 

The CVDDQ voltage is about 3.27 - 3.35

[Rashi_Vatsa]

Hi,

Please fill up the schematic and layout checklist from AN70707 https://www.infineon.com/dgdl/Infineon-AN70707_EZ-USB_FX3_FX3S_SX3_hardware_design_guidelines_and_sc...  and share.

This will help us to narrow down the issue

[PraveenAmara]

Hi Rashi_Vatsa 

Please find the check list attached below. 

[Rashi_Vatsa]

Hi,

Thank you for the details.

From the checklist, the Reset circuit and SS USB routing guidelines are not met. We recommend following all the guidelines mentioned in AN70707.

Please let me know if the heating issue is seen in multiple boards or is it only seen with one particular board. The current testing is being done using the default USBBulkSrcsink example of the SDK Is my understanding correct? If now, please check if the issue is reproducible with default USBBulkSrcSink example of SDK.

One more test that can be done is using a firmware (like GpioApp) which doesn't uses USB lines / block of FX3 so that we can narrow down further.

[PraveenAmara]

Hi Rashi Vatsa

Sorry for the late reply. 

Yes, We are facing a heating issue on the multiple boards. 

Do you think reset circuit may create the heating issue?  I will update you regarding the test in the following reply. 

[Rashi_Vatsa]

Hello,

We have seen similar issues when the FSLC setting or the clock is not proper.

[PraveenAmara]

Hi Rashi_Vatsa

This is our 4th version, Even previous version we followed the same FSLC setting. 

Only on this version, we are facing a thermal Issue. 

• FSLC[0]: HIGH
• FSLC[1]: LOW
• FSLC[2]: HIGH

Also, I have a doubt that we are not using a pullup and pulldown resistor in the FSLC line. Are there any possibilities? 

[Rashi_Vatsa]

Hello,

From FSLC and clock , I meant that thermal issue could be due to clock not meeting the specs or the routing of clock is not as per AN70707.

I understand the latest version of the board, only size is being reduced and other components or the schematics are same. Is my understanding correct? If yes, please refer to the layout guidelines in AN70707

CVDDQ power domain is related to clock. Is it possible for you to try changing CVDDQ from 3.3 > 1.8V?