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Altera_Forum's avatar
Altera_Forum
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15 years ago

power supply requirement for cyclone II

we are in design process for our new design using cyclone II series FPGA,

We have a doubt regarding a power supply requirements.

In EP2C5 datasheet it is given that 1.2V as AVDD(analog supply)

and another 1.2 V as DVDD(digital supply), our question is whether

we can use single 1.2V supply for Avdd and DVdd or we have to use seperate 1.2V supplies.

Waiting for your reply

1 Reply

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

    You should implement the suggested passive filtering for PLL supply VCCA. Some development kits actually use a separate voltage regulator for VCCA, but I never used it. You should consider however, that besides high frequency interferences also mid frequency ripple of the PLL supply can cause excessive jitter and even loss of lock.