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DownInFlames's avatar
DownInFlames
Icon for New Contributor rankNew Contributor
2 years ago

When does the tRAMP timing begin for Cyclone 5 Power Supplies?

Hi All,

I am currently designing a power supply setup for a Cyclone 5 FPGA.

In the datasheet, it is stated that if power supplies do not reach operating conditions within the maximum tRAMP time allowed (100ms in my scenario with standard POR delay) the device will remain tri-stated.

My question is, does the tRAMP spec apply to each different supply individually? Or, does it apply to each supply as a whole? e.g. Can I switch on the Vcc supply (ramps within say 10ms) and then wait a few seconds and switch on another supply? Or, must they all turn on within 100ms after the first supply begins to ramp?

The image below is an extract from the datasheet, Figure 10-4 of the Cyclone V Handbook Volume 1, and seems to imply they can be timed individually?

Configuration
Power

2 Replies

  • Farabi_Altera's avatar
    Farabi_Altera
    Icon for Regular Contributor rankRegular Contributor
    2 years ago

    Hello,


    Yes, the tRAMP should be counted individually for each power rail. POR(Power One Reset) circuitry is monitoring each of this power rails individually.


    regards,

    Farabi


  • Ash_R_Altera's avatar
    Ash_R_Altera
    Icon for Regular Contributor rankRegular Contributor
    2 years ago

    Hi,

    I hope the query was answered by Farabi to your satisfaction. Hence, I am closing the case. However, it will be open for the community members to comment on.


    Thanks and regards