AM3871 AUX_CLKIN Connection

Ajesh Prabhu

Other Parts Discussed in Thread: AM3871

Hi,

I am designing a custom PCB which has AM3871 on it. We are not planning to use any audio or video functionality and so don't have a need to add the additional crystal or a oscillator to source the AUXOSC_MXI/AUX_CLKIN pin.

The question is, since this function is optional, can I just pull the pin up?

Thanks,

-Ajesh

over 9 years ago

0 Biser Gatchev-XID over 9 years ago

TI__Guru**** 393215 points

Moving this to the AM387X forum.

0 Pavel Botev over 9 years ago

TI__Guru**** 170625 points

Hi Ajesh,

For how to handle unused pins, refer to the AM387x datasheet, section 4.4 Handling Unused Pins

Regards,
Pavel

0 Ajesh Prabhu over 9 years ago in reply to Pavel Botev

Prodigy 30 points

Hi Pavel,

Thanks, I did read that section and it says that if the signal pins are unused, they can be left open unless otherwise noted in section 3.2 Terminal Functions.

In section 3.2, nothing is mentioned for the AUX_CLKIN, other than to say it is optional. I am afraid to leave it open as it does not have an internal pull-up or pull-down, but also is an analog signal, so I guess it is okay.

Regards,

-Ajesh

0 Pavel Botev over 9 years ago in reply to Ajesh Prabhu

TI__Guru**** 170625 points

Ajesh,

In the 4.4 section we have this statement: For unused input pins, the internal pull resistor should be enabled, or an external pull resistor should be used, to prevent floating inputs.

So, for unused input pins, you should use internal/external pull resistor, for unused output pins, you can leave unconnected (unless otherwise noted in section 3.2).

AUX_CLKIN is input pin.

Regards,
Pavel

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AM3871 AUX_CLKIN Connection