Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
18 years ago

Cyclone III using 3.3V power supply

Hi there,

my embedded system is based on a Cyclone III powered using an external 3.3V power supply. I already found the solution used in DK-DEV-3C120N to drive 1.2V (core) and 2.5V (PLLs) using a 3.3V supply.

But I'm still locking for a smart solution (i.e., low price and small area) to supply a smaller device (i.e., EP3C40F484C6N) with a lower power consumption efficiently.

Can anyone help me with that?

Thanks in advance

Modellpilot

4 Replies

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

    For 500 mA from 3.3V, a LT1963A in DD-Pack could be used, a synchronous switcher would give lower power dissipation. All major manufacturers have suitable devices, I have used TI TPS62040 previously, see appended circuit.

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

    To give a ballpark figure, we are talking about 300..500 mA. Do you have any suggestions regarding the voltage regulator (maybe including a schematic)?

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

    The best soultion depends mainly on the power demand of your application, particularily for core supply. It may range from a few 10 mA to several A. Linear voltage regulator solution may be suitable up to at least some 100 mA, it's clearly the cheapest solution.