Thanks for the replies Dan, Francois, and John,
We will be drawing power from the correlator.
We have 3.3 Volts at substantial current available.
5 Volts at limited current (less than an amp) so it would not be of use.
We can add a jumper to provide 48 Volts.
It was mentioned that the sequencing of the power was important. If we
use our existing 3.3V and the
48 V to generate 5V and 12V, then if the 48 V is unplugged there could
be only 3.3V. Would that be a problem?
I am tending towards using the 48V to a DC-DC converter to give 12V.
Then routing the 12V to the Pico device to supply all the power.
This would eliminate using the on-board 3.3V.
Too bad tthe Pico device doesn't come in a 48V model.
Thanks for all the help,
Joe
Dan Werthimer wrote:
hi joe,
the DC-DC converters are standard on the roach boards,
so you only need to supply 3.3, 5 and 12 volts to the ATX connector.
if you use john ford's $30 pico-PSU-90, then you only have to supply
one voltage: +12 Volts at 8 amps.
i'm not sure about the maximum currents for each of the
roaches three input voltages.
i'm cc'ing the casper lists - someone will know.
i can measure these currents with our clamp on amp-meter, but these will
change a bit, depending on how heavily you load the FGPA and what
ADC's are plugged into the roach board.
best wishes,
dan
On Thu, Jan 19, 2012 at 10:53 AM, Joseph Greenberg <[email protected]
<mailto:[email protected]>> wrote:
Hi Dan,
Thanks for the reply.
Dan Werthimer wrote:
hi joe,
can you leave the DC-DC converters on the roach board?
Yes. Are they standard on all Roach I boards or do we have to
specify them?
then you only need to supply the 12, 5 and 3.3 volts that
come from the ATX power supply.
What is the maximum current we would need to supply for each of
these Voltages?
Thanks,
Joe
best wishes,
dan
On Thu, Jan 19, 2012 at 10:28 AM, Joseph Greenberg
<[email protected] <mailto:[email protected]>> wrote:
We at NRAO are going to mount the Roach I board on a custom
board, rather than using the usual chassis.
We will have DC-DC converters on the board.
The Roach documentation states:
Voltages of 12V, 5V, 3.3V, 2.5V, 1.8V, 1.5V, 1V and 1.2V aux
rails.
Is there any specification of what maximum currents we need
to supply for each voltage?
Thanks,
Joe
