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Altera_Forum's avatar
Altera_Forum
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10 years ago

Current from on board voltage sources

Does anyone know how much current can be drawn from the +5V and +3.3V supplies that are available on the expansion headers of the DE0 board?
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
10 years ago

The board has a 1A regulator for 3.3V and two 1A regulators (that are diode OR'd together - not very elegant) for 5V.

However, the 3.3V regulator feeds all the on-board circuitry - FPGA, memory, LEDs etc - as well as the expansion headers. So, you'll have to make a judgement as to how much of that 1A current capacity you 'lose' to that circuitry.

Furthermore, the 3.3V rail is derived from the 5V rail. So, the 5V rail is responsible for sourcing all the current consumed by the 3.3V rail. So, whatever current you're already losing to the 3.3V rail, you're losing from the 5V rail too.

Cheers,

Alex