FEC83
-----

Used in Japan.
Do not work any longer.
Brought to Lund 20140702 to Lund by Katsumasa IKEMATSU.

The card draw too much current:
0.7A when PCA16 is shutdown.

The PCA16 regulator can not give enough current:
It has the old regulator 
MIC29372 1.5V  PCA16 max current: 1.1A typical

Other regulators are 
MIC39151 2.5V Altro Dig
MIC39301 2.5V Altro Ana

The PCA16 regulator should be changed to MIC2941
which has lower drop voltage and higher current capability
(1.25 A gauranteed).

Tests done
==========

The tests are done by taking pedestal runs and looking at the
pedestals. Channels with pedestals that deviate from working
channels are considered not working.


Two plots in the files:
first one with PCA16 on, second with PCA16 in shutdown mode.

The plots in the files show the pedestal (red, left scale)
and rms of pedestals (blue, right scale).

Power through voltage regulator:
combined-fec83-shutdown-2.8V.pdf

To be compared with working FEC77:
combined-fec77-shutdown-2.8V.pdf

To be able to provide enough current was the regulator bypassed,
by connecting PS ground to FEC connector ground and 1.5V to
PCA16 1.5V test point.

Measured current: 1.2A

The pedestal plot in this mode,
where only the first plot is relevant:
combined-fec83-shutdown-1.5V.pdf

the plot show that:
chip 4 channels   4,5,6,12,13,14
chip 5 channels 3,4,5,6,      14
are not working

These two chips (4 and 5) should be replaced.