Re: [Discuss-gnuradio] Maximum DC supply voltage for USRP

[Eric Blossom]

On Tue, Jul 31, 2007 at 04:07:14PM -0400, Marcus Leech wrote:
> What is the maximum DC supply voltage for the USRP?
> 
> I've been running it off of a 5V switched supply, but I wanted to move
> all power
>   supplies outside of the USRP cabinet that I have, so I'm using an
> external 13.8V
>   supply, with a LM7805 regulator.  The regulator is sagging due to high
> current
>   demand, so I'm thinking of supplying 13.8V directly to the USRP--is
> this safe?

No, the on board regulator can't dissipate the resulting power.

You really should feed the USRP with 6.0V, not 5.0V.  Some
daughterboards take 6.0V and produce a local 5V analog supply from it.
In a pinch, you could probably feed it 5.5V, but I wouldn't go any lower.

Eric