extended dynamic range for CCD instruments.

[Craig D Mackay]

Posted to CCD-world:
-+-+-+-
Dear Chris

The use of dual ADCs to increase dynamic range was, I think, first used
in the AstroCam 4220 controller that was first marketed around 1990.  
The way of using two ADCs was described in a paper I wrote for the Feb
93 Jan Jose meeting, and can be found in SPIE vol 1900, p12.

The method you describe is exactly what we used.   It works well
provided you merge the two 16-bit values carefully where they overlap.

The method is particularly used by laboratory spectroscopists who do
full parallel binning into the output register and can easily get a full
well in excess of 1,000,000 electrons with CCDs that have a read noise
of 3 or 4 electrons.

Best Wishes

Craig D Mackay


Chris Stubbs wrote:
> 
> Posted to CCD-world:
> -+-+-+-
> 
> Greetings.
> 
> A while ago there was some exchange of messages about realizing the
> full dynamic range of CCD's... We have a very brief write-up on
> a scheme that should allow read-noise and shot-noise limited performance
> up to the entire binned full well depth of a CCD detector, using dual
> A/D converters.
> 
> I have put a PDF file of the write-up at the very bottom of my
> web page, http://www.astro.washington.edu/stubbs.
> 
> Christopher Stubbs
> University of Washington.
> 
> -+-+-+-
> For information about CCD-world, send email to owner-CCD-world at cfht.hawaii.edu.
-+-+-+-
For information about CCD-world, send email to owner-CCD-world at cfht.hawaii.edu.