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Altera_Forum's avatar
Altera_Forum
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12 years ago

EP1C12 high standby power consumption

Hello everyone!

I was a little bit surprised when I measured the standby (unconfigured state) current consumption of an EP1C12 device's VCCINT power rail. It was 44 mA. (VCCINT=1.5V, all VCCIO=3.3V)

My question: Is this normal?

I checked the Altera Cyclone Device Power Calculator Spreadsheet and it says 8 mA standby current as typical. Worst-Case is 55 mA, but I expect something closer to the typical value.

Does anybody has any idea what can cause this higher power consumption?

Thanks for your help in advance.

Peter

4 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    12 years ago

    I know Altera struggled with inrush on some of the earlier family members. (I know the original Stratix has this issue)

    Does the current drop once the device is configured?

    If I remember properly the issue was internal contention, due to the rams powering up in a random state. That could be why the spec has such a large window between typical and worse-case.

    Pete
  • Altera_Forum's avatar
    Altera_Forum
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    12 years ago

    sounds about right, you're between typical and maximum. i've found typical is an optimistic number

  • Altera_Forum's avatar
    Altera_Forum
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    12 years ago

    The numbers sound fine to me. Does the device behave as expected? Does it configure? If so, I'd suggest all is well...

  • Altera_Forum's avatar
    Altera_Forum
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    12 years ago

    Thanks for the replies!

    Yes, there is no problem with the device at all. It works as expected and it is configurable as well.

    We previously used EP1C6 devices on our boards and those chips consumed <10mA in standby. I know that EP1C12 devices are much more power hungry, but I did not expect as "high" value.

    I just wanted to ask others, because maybe I should start searching for some hardware errors.

    Thanks for the "random ram powering up" explanation, but it is a little bit strange that several EP1C12 consume approximately the same 44 mA value...