AM3352: AM3352 Design Review

John DeCesare

Part Number: AM3352

Hi!

I have a design using the AM3352 and the TPS65218D PMIC. I have requested a design review for the TPMIC which is underway (thanks!) but I would also like for TI to review the AM3352 since this is a new part for me. I have reviewed many documents including the following:

Datasheet
Eval Schematic (sprr164)
AM3352 Schematic Checklist (SPRABN2A)
AM3352 Hardware Design Guide (SPRABU5)

So I'm fairly confident with the design but I would appreciate if I could provide a schematic (privately) for TI to review.

Thanks so much!

John

9 months ago

0 Kallikuppa Sreenivasa 9 months ago

TI__Guru**** 232565 points

Hello John,

Thank you for the review request.

We will support to the best.

Can you help me confirm if you are working with TI SALES/Support teams?

Regards,

Sreenivasa

0 John DeCesare 9 months ago in reply to Kallikuppa Sreenivasa

Intellectual 420 points

Hi Sreenivasa,

I just simply entered this ticket as I often do. I don't know what you mean about TI sales team.
Thanks!

John

0 Kallikuppa Sreenivasa 8 months ago in reply to John DeCesare

TI__Guru**** 232565 points

Hello John,

Thank you.

The schematics review are typically supported through TI filed team (TI sales or support) you are may have been working.

The question here is are you working with any TI sales or support team.

Regards,

Sreenivasa

0 Kallikuppa Sreenivasa 8 months ago in reply to Kallikuppa Sreenivasa

TI__Guru**** 232565 points

Hello John,

In case you are not working with any TI sales team, i would suggest sharing the schematics over private chat.

I can have a look and suggest the next steps.

Regards,

Sreenivasa

0 John DeCesare 8 months ago in reply to Kallikuppa Sreenivasa

Intellectual 420 points

Hi Sreenivasa,

Yes. I have been working with TI with the associated PMIC and provided Sarah the schematic via her email privately. Is this some thing we can do?

Thanks!!

John

0 Kallikuppa Sreenivasa 8 months ago in reply to John DeCesare

TI__Guru**** 232565 points

Hello John,

Thank you.

I assume you are working with Sarah over E2E.

I was checking if you are working with any of the TI sales teams.

Please share the schematics over private chat.

Regards,

Sreenivasa

0 John DeCesare 8 months ago in reply to Kallikuppa Sreenivasa

Intellectual 420 points

Hi Sreenivasa,

How do I do this over "private chat"? Is there an email I can forward the schematics to you?

Thanks!

John

0 Kallikuppa Sreenivasa 8 months ago in reply to John DeCesare

TI__Guru**** 232565 points

Hello John,

Thank you.

Please check if you were able to receive a friend request.

If not please look for private message section on the E2E page and send over a message.

Regards,

Sreenivasa

0 Kallikuppa Sreenivasa 8 months ago in reply to Kallikuppa Sreenivasa

TI__Guru**** 232565 points

Hello John,

Thank you.

I acknowledged over E2E.

Regards,

Sreenivasa

0 Kallikuppa Sreenivasa 8 months ago in reply to Kallikuppa Sreenivasa

TI__Guru**** 232565 points

Hello John,

I shared the review comments over the chat.

Regards,

Sreenivasa

0 Kallikuppa Sreenivasa 8 months ago in reply to Kallikuppa Sreenivasa

TI__Guru**** 232565 points

Hello John,

Please refer below FAQ for additional information:

https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1189177/faq-am3351-am3352-am3354-am3356-am3357-am3358-am3359-custom-board-design-collaterals-to-get-started

https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1384494/faq-am3351-am3352-am3354-am3356-am3357-am3358-am3359-custom-board-design-e2e-faq-references-and-design-guidelines-for-reference-during-custom-board-design

Regards,

Sreenivasa

0 John DeCesare 7 months ago in reply to Kallikuppa Sreenivasa

Intellectual 420 points

Hi Sreenivasa,

Sorry but I cannot find where your schematic review comments are? Is the "chat" the links above? I don' see anything else.

John

0 Kallikuppa Sreenivasa 7 months ago in reply to John DeCesare

TI__Guru**** 232565 points

Hello John,

Please check the chat.

Regards,

Sreenivasa

0 John DeCesare 7 months ago in reply to Kallikuppa Sreenivasa

Intellectual 420 points

Hi Sreenivasa,

Thanks for such a thorough review!! I da have a few questions:

1. The RTC_KALDO_ENn signal is confusing to me. I want to support RTC-Only Mode but with the lowest power consumption. So I THINK I should pull RTC_KALDO_ENn low (R19) and feed CAP_VDD_RTC with VDD_1V0 via R142. If I want to use the internal LDO, then I pull RTC_KALDO_ENn high (R143) and do NOT drive CAP_VDD_RTC with 1V. Is this correct?

2. You mention open-drain in WARMRSTN yet in the document (SLVUAA9B) it shows connecting GPIO3 of the PMIC connected directly to WARMRSTN. What would be the requirement for the open-drain buffer?

3. EMMC reset and clock. For the reset, you refer me to the Beagle Board which is where I copied that. You mention a pulldown on Clock but on the beagle board, it is pulled high, as is what I did in the schematic.

4. Is DDR CLK_P/N termination required?

5. You mention a large RC on the JTAG connector so I think you are referrring to the 100ohm/0.1uf? If so, this is the same RC as used on the Beagle Board.

Thanks!!

John

0 Kallikuppa Sreenivasa 7 months ago in reply to John DeCesare

TI__Guru**** 232565 points

Hello John,

Thank you.

John DeCesare said:
4. Is DDR CLK_P/N termination required?

With proper trace impedance, we have never required that the differential clock be terminated for single device DDR3 designs with AM335x

John DeCesare said:
EMMC reset and clock. For the reset, you refer me to the Beagle Board which is where I copied that. You mention a pulldown on Clock but on the beagle board, it is pulled high, as is what I did in the schematic.

Please follow the beagle bone green implementation.

eMMC_CLK has an internal pulldown, To be safe and immune to noise, provision for external pulldown is recommended. You could make the clock pullup DNI.

John DeCesare said:
You mention open-drain in WARMRSTN yet in the document (SLVUAA9B) it shows connecting GPIO3 of the PMIC connected directly to WARMRSTN. What would be the requirement for the open-drain buffer?

Reference section:

Inputs related to cold and warm reset

Please follow the beagle bone green schematic

Regards,

Sreenivasa

0 Kallikuppa Sreenivasa 7 months ago in reply to Kallikuppa Sreenivasa

TI__Guru**** 232565 points

Hello John,

Refer below section for the allowed configurations:

John DeCesare said:
1. The RTC_KALDO_ENn signal is confusing to me. I want to support RTC-Only Mode but with the lowest power consumption. So I THINK I should pull RTC_KALDO_ENn low (R19) and feed CAP_VDD_RTC with VDD_1V0 via R142. If I want to use the internal LDO, then I pull RTC_KALDO_ENn high (R143) and do NOT drive CAP_VDD_RTC with 1V. Is this correct?

Inputs related to connection of signals for RTC functionality

I suspect you will have to disable the internal LDO of the processor.

Since you have the provision, may be it works best to perform some tests.

Regards,

Sreenivasa

Processors

Processors forum

AM3352: AM3352 Design Review