AM3352: VDDS_RTC issue

WU YISYUAN

Part Number: AM3352

Hi,

I used AM3352 in my product have some question.

After the product was tested from the factory, after sampling the product, it found no output.

After confirming, it was found that VDDS_RTC (D7) was short-circuited.
I want to know what causes the pin to be damaged.
In addition, the specification defines D7 maximum current withstand 5mA, want to confirm whether it is only 5mA?
The schematic of this part is as follows:
Thanks.

over 6 years ago

0 Biser Gatchev-XID over 6 years ago

TI__Guru**** 393215 points

Hi,

You have errors in your schematic:

VDDS_OSC is not connected. This is the oscillator power supply and must be connected to 1.8V.

Check your RTC connection as described in section 2.14 of http://www.ti.com/lit/an/sprabn2/sprabn2.pdf You have errors there too.

0 WU YISYUAN over 6 years ago in reply to Biser Gatchev-XID

Expert 2165 points

Hi Biser,

I updated my schematic as shown in the article.

In fact, VDDS_OSC has connected power supply 1.8V.

Please help to confirm what other causes VDDs? RTC (D7) damage?

thanks.

0 Biser Gatchev-XID over 6 years ago in reply to WU YISYUAN

TI__Guru**** 393215 points

I cannot say from these partial schematics. I suggest you compare your schematic to one of the reference designs:

http://www.ti.com/tool/TMDSSK3358#technicaldocuments

http://www.ti.com/tool/TMDXEVM3358#technicaldocuments

The AM335x schematic checklist is also useful: www.ti.com/.../sprabn2.pdf

0 WU YISYUAN over 6 years ago in reply to Biser Gatchev-XID

Expert 2165 points

Hi Biser,

            Thank you for your feedback and suggestions,
            However, the English reference specification you provided has more than 5000 pages. We are not sure what we need to focus on,
            And it is easy to be missed in the confirmation process. Can you tell us what are the important specifications or parts that need our special attention so that we can speed up the analysis?

thanks.

0 Biser Gatchev-XID over 6 years ago in reply to WU YISYUAN

TI__Guru**** 393215 points

On the reference design links above you will find schematics in PDF format. None of them are 5000 pages. The AM335x schematic checklist is also 10 pages long.

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AM3352: VDDS_RTC issue