TPS562200: TPS562200 harmonies and thermal shot down

Hi,

I didn't find the attached SCH, Could you help share the sch and layout for us to review ?

and how many layers of this pcb ?

BRs,

Young

Hi Jafar, 

Ripple is too large. Could you share Vin, Vout and SW waveform to debug? If you can provide more detail information, such as schematic, layout, waveform, abnormal behavior picture, we can help quickly find some clue. 

BRs, 

Edwin. 

Hello Young,

Thanks for the answer.

here is the Schematic:

This is the TPS562200 output (5V)

How can I share the layout with you?

Hello Edwin, Its a 6-Layer PCB. I share more Screenshots. please have a look.

3D_View_TopLayer:

TPS562200_Toplayer_1:

TPS562200_TopLayer_2:

3D_View_BottomLayer:

BottomLayer:

EMC_Result:

Hi Jafar, 

It looks no problem for schematic and layout. Could you share the waveform of thermal shut down(Vin, Vout and SW)? 

BRs, 

Edwin. 

Hello Edwin,

here are the waveforms.

Input:

SW:

Output:

Thanks for your support

Hi Jafar, 

The waveform is not regular working waveform. how do you think it trigger thermal shut down? did you test thermal of the IC? 

BRs,

Edwin. 

Hello Edwin,

yes, we measured the temperature on the IC. the temperature goes up to 150!

so, basically, we have 3 problems, one is the noisy waveforms, the second is a failure in EMC (please see the screenshot result in my previous messages) which probably is coming from problem #1, and the third problem is thermal shot down at 1.9A output current. I was wonder if by solving problem #1, the other 2 problems may be solved or be better eventually. 

Regards,

Jafar

one more thing, when the thermal shutdown happens, a voltage pick around happens at the output for a short time. this pick may defect some other components. here is a screenshot of the output waveform when the shot down happens:

Hi Jafar, 

could you plot Switching, Vin, and Vout in one figure when Vout has a spike voltage? and does the circuit do anything to trigger this happen? 

BRs, 

Edwin. 

Hello Edwin,

here are the waveforms all together:

Yellow: 12V input

Blue: SW output

Purple: 5V output

The module gets too warm at 1.9A output. Does it related to the functionality? how to solve it?

Regards,

Jafar

Hi Jafar

Edwin is looking into this and will feedback to you soon.

BR

Ruby

Hi Jafar, 

The waveform should test at light loading. could you help to plot at 1.5A or 1.9A loading waveform. and could you help to plot the waveform with issue happening. 

BRs, 

Edwin. 

Hello Edwin,

Here is the requested waveform under the 1.5A load. the result for the 1.9A load is also the same.

Yellow: 12V input

Blue: SW output

Purple: 5V output

Regards,

Jafar

Hi Jafar, 

From this waveform, it looks like no problem. Could you help to take a picture of how you test the board? The switching noise is big. I would like to see how you use probe to test the board. 

Could you help to plot the waveform of moment that happen thermal shut down? 

BRs, 

Edwin. 

Hello Edwin, I already sent you a plot of the thermal shutdown before, please see the history on this page. Here are photos of how I put the probe on the PCB. I have soldered a wire on the pin and measure using an osiloscope. If I put the probe directly on the pin, the result will be the same.

Regards,

Jafar

Hi Jafar, 

The ground line is too long. It's still suggested to probe to board to test. I mean the waveform with all signal Vin, SW, Vout? By the way how many board do you test? and how many board does it have this kind of thermal shutdown? 

BRs, 

Edwin. 

Hello Edwin,

Yes, I measure all the parameters like this. I have tested more than 10 boards, all of them have this thermal shutdown when the output load is more than 1.9A. the shutdown happens in around 15 min of operation time. another problem is the noisy waveforms that I already sent you some photos about.

Regards,

Jafar

Hi Jafar

Edwin is looking into this and will feedback to you soon.

BR

Ruby

Hi Jafar, 

Got it. It's suggested to share more waveforms for me to debug, especially the issue waveform. or is it ok to have a meeting to discuss? Based on current waveforms, the information is small. It's difficult to find the root cause. 

BRs, 

Edwin.