Adapt default parameters for PSI46digV2 chips according to Hans-Christians
suggestions to Jan (ETH):

"Hans-Christian has new recommendations for some DAC settings to get rid of
the multi dimensional PH DAC optimization. The new DAC settings are:

Vbias_sf = 6
VoffsetOp = 85
VIon = 128
VComp_ADC = 100

With these settings only VIref_ADC and VoffsetRO need to be optimized which
makes the procedure a lot easier. I have tested it and I was able to cover
the full ADC range within the dynamic range of these two DACs (see attached,
plotted range VIref_ADC [50..250] and VoffsetRO [20..140] ). An automatized
optimization of these two DACs has been implemented by Marco as part of the
pretest.

Covering the full ADC range with optimizing VIref_ADC and VOffsetRO only is
also possible for irradated ROCs (tested up to 120 Mrad). However, an
additional increase of Vdig is required for proper address decoding and
sufficient PH gain."