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Altera_Forum's avatar
Altera_Forum
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14 years ago

Temperature affects output frequency

Hi all,

I have a problem with a Cyclone III FPGA. I generate a frequency around 40MHz by PLL but the frequency drifts +/- 500kHz depending on the FPGAs temperature. The frequency rises by cooling and decreases by heating the chip. The temperature range I tested was in the field of +60°C to +10°C. Is the PLL affected by temperature that much?

Has anyone an idea what the problem could be?

Greets,

cappuMUC

2 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    14 years ago

    What is the clock source that feeds the PLL? Are you sure it's not the source that's drifting?