• State
  • Locked Locked
  • Replies 4 replies
  • Subscribers 98 subscribers
  • Views 155 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

AM3874 pin handling

Michi Yama
Guru 10030 points
Other Parts Discussed in Thread: AM3874

Hi,

I would like to handle of the below pins of AM3874.

1) Reserved Pins : RSV18-RSV22      These pins is recommended to connect 1uF Capacitor. What for are these capacitance used?

2) AUX_CLKIN, UART0_RXD :  Our customer does not use these pins in their system.  I think NC is acceptable for these pins. Is my understanding right?

Please let me know.

Best regards,

Michi

  • 0
    TI__Guru**** 393215 points
    Hi Michi,
     
    1. These are load capacitors for internal power supplies. They are absolutely necessary.
    2. For unconnected pins, check AM387X Datasheet, Section 4.4. For AUX_CLKIN nothing more specific is mentioned, so it should be OK to leave it unconnected. For UART0_RXD the internal pullup is switched on by default, so no problem there too.
  • 0 in reply to Biser Gatchev-XID
    Guru 10030 points

    Dear Biser-san,

    Thank you for your support.

    I would like to know more information regarding AUX_CLKIN pin. If some noise is entered to the internal logic of AM3874 from AUX_CLKIN pin, is there any possiblity that AM3874 become to be  unstable? If it is no worry about unstableness, our customer would like to leave it unconnected.  Could you give me more adivces?

    Best regards,

    Michi

  • 0 in reply to Biser Gatchev-XID
    Guru 10030 points

    Dear Biser-san,

    Thank you for your support.

    If you can't claim that some noise from AUX_CLKIN pin is no problem for AM3874 stable,  I will recommend to our customer to add pin handling. Simple handling is to

    connect to GND. Is this way enough for AUX_CLKIN? Or is it needed to add pull-up/down?

    I appreciate your quick reply.

    Best regards,

    Michi

     

  • 0 in reply to Michi Yama
    TI__Guru**** 393215 points
    Hi Michi,
     
    Nothing specific is menioned in the datasheet about the AUX_CLKIN unused pin handling, so I don't think there is any danger in leaving it unconnected. Moreover it's on the package edge and can be easily surrounded by a GND island.