Rossi,
I’m a bit confused as to what you are asking. But here is
what I think you are asking. You are using the +5V line supplied by the
USB-6008 to power your LM385. You also are using the some of the 6008s analog
inputs that are configured to read a voltage in the range of 0-3V. You are
wondering if this 0-3V input range will affect your 5V supply that is powering
your LM385.
If this is your question, the answer is no. The input range
will have no effect on the +5V supply line on the device. The analog inputs go
through some gain amplifiers, that are configurable, hence the ability to
change the range. But the 5V supply line is a direct connection to the 5V that
powers the whole unit.
You also asked if it was a good idea to power the LM385 off
of the USB-6008. The only limitation that I can think of is limited current.
Since the USB-6008 is powered off of the USB port, which doesn’t supply that
much current to begin with, you will limited in this same respect for powering
anything. Take a look through the USB-6008 Data Sheet for specs like these, but
you will notice that at a max the 6008 can only source 200mA. So depending on
everything else you want do, and how many things you need to power you could potentially
run into a current limitation. So just be aware of your limits there.
Hope that was helpful.
-GDE
