Separate GNDx connection

[Olaf Iwert]

Dear CCD afficionados,


Thanks a lot for the recent help on my request concerning 
"Sharing of bias phases". In summary the answers point into the direction 
that practical experience in this matter is not always in agreement with the 
theory - quite a common phenomenon related to CCD behaviour
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Here it goes with another request :

Looking carefully at the SITe CCD data sheets, one finds a separate 
GND(a/b/c/d) connection to the bulk of each output transistor on-chip.

While we would really like to minimize the cross-talk between the different
readout channels, the following questions occur :


1.) Is the output amplifier really isolated from the rest of the substrate 
    this way ?

Clocks and Bias signals are generated versus a certain ground potential,
also the video chains have a certain reference potential.

2.) Has anyone of you done something different than connecting the individual
    output transistor GND(a/b/c/d) pins to the SUB / PKG GND ?

3.) Is anyone running this ground completely separated from the rest of the 
    other grounds - and, if yes : HOW ?


Thanks in advance


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  Olaf Iwert                        E-mail :               oiwert at eso.org  
  European Southern Observatory     Phone & Voice Mail :   +49-89-320-06-353  
  Optical Detector Lab              FAX :                  +49-89-320-23-62
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