TPS659037: Ball OSC16MCAP (C1) is grounded, correct?

John11513

Part Number: TPS659037
Other Parts Discussed in Thread: TMDXIDK5718

Hi,

In our AM571X EVM (TMDXIDK5718) schematic, the C1 ball (OSC16MCAP) is grounded. My customer follow this design however found that the VCC is shorted to GND. The root cause was determined to be the grounded OSC16MCAP ball. The shorting issue disappeared once the ball was floated. I read the datasheet it says this ball should be bypassed to GND through a 2.2uF cap or floating. And I think it should not be grounded as an output pin. I am wondered why our EVM is designed with this ball grounded? and why my customer's board VCC is shorted to GND with same design?

Thank you,

John

over 7 years ago

0 Krishnamurthy Hegde over 7 years ago

TI__Expert 8730 points

Hi John,

I have assigned your request to concerned Applications Engineer and we will get back to you as soon as possible. Please note that this is vacation time in US and there may be some delay in answering your question.

Regards,

Murthy

0 Karl Wallinger over 7 years ago in reply to Krishnamurthy Hegde

TI__Genius 16410 points

Hello John,

You are right that grounding the OSC16MCAP pin will cause VCC to be shorted - this pin is internally connected to VCC. So the customer should not do that on their board.

I'm checking with the AM571x team to see how or why it was designed this way - hopefully we can get the documentation corrected.

Regards,
Karl

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TPS659037: Ball OSC16MCAP (C1) is grounded, correct?