• State
  • Locked Locked
  • Replies 3 replies
  • Subscribers 102 subscribers
  • Views 411 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Dual chip ( 2x AM335x) system - how to solve powering ?

Jaroslaw Karwik
Prodigy 205 points
Other Parts Discussed in Thread: AM3352, TPS65217

I am designing system with two SItara AM335x processors ( most likely AM3352 )

My original idea was to use separate TPS65217C chips and just combine PGOOD from them - to avoid non-sequencial power of cpu's ( which do have interconnections) . This plus slaved external 3.3V dc/dc converter ( I need quite much for peripherials - almost 2A )

But is there a better way ? Is there a chip which could handle both CPU at once (TPS65217x does not hint it could be used like that) ? 

I will not be using any sleep mode - basically full power from the start, no sleep modes.

  • 0
    TI__Guru**** 393215 points

    Hi Jaroslaw,

    If you want to take advantage of the dynamic frequency/power scaling features that AM335X supports you will need to use two separate PMICs - one for each processor.

  • 0 in reply to Biser Gatchev-XID
    Prodigy 205 points

    I will have two identical CPU's configured (after startup) to maximum frequency. Once and forever.

    So basically this is fixed frequency scenario and I could use same voltages for both.

    But I have never seen any reference design which would show how to safely implement such design once power sequence is quite sensitive.

    Power comsumption from http://processors.wiki.ti.com/index.php/AM335x_Power_Consumption_Summary shows that single TPS65217C should be capable for running two processors with 1GHz frequency, but I am not sure about its safety margins as most likely nobody tried that.

    Well I could try to adapt  something higher power - e.g. TPS659113 , but this would be non-trivial - with no reference I would rather copy 1:1 part of Beaglebone Black as good proven reference.

  • 0 in reply to Jaroslaw Karwik
    TI__Guru**** 393215 points

    I agree with your last comment. A single TPS65217 powering two processors @1GHz is risky in my opinion too.