version 2.0 rev 18 Feb 2021
25
The method of combining signals from two 11-bit ADCs can be divided into four basic steps.
1. Attheendoftheanalogchainthe“Signal”voltageisappliedtotwoindependentampliers:thehigh
gainamplierandthelowgainamplier.Thisresultsintwoseparatedigitaldatastreamsfromthe
sensor
2. The camera selects which data stream to use on a pixel per pixel, frame by frame basis using a
threshold method
3. ThedataisthencompensatedforDCosetandgain.Again,thisisdoneonapixelbypixelbasisusing
the compensation data associated with the data stream. The gain corrects for pixel to pixel relative
sensitivity,pixelnodeamplierandthehighandlowamplierrelativegains
4. The pixels are then combined into a single 16-bit image for transfer to the PC
The user maintains the choice of opting to stay with 12-bit single gain channel data if dynamic range is not
critical,resultinginsmallerlesizes.Thisinturnoersfasterframerateswhencontinuouslyspoolingthrough
the Camera Link interface and writing to hard disk.
Table 4: Typical performance of supported gain settings of the Zyla 5.5 (Jan 2012 onwards)
AmplierGain
(Current Andor SDK / Solis description)
Mode
Sensitivity e
-
/
ADU (typical)
Data
Range
Eectivepixelsaturation
limit / e
-
Spooling File Size
(per frame)
12-bit (high well capacity) GS/RS 7.5 12-bit 30,000 8 Mb
12-bit (low noise) GS 0.42 12-bit 1,700 8 Mb
12-bit (low noise) RS 0.28 12-bit 1,100 8 Mb
16-bit (low noise and high well capacity) GS 0.45 16-bit 30,000 10.5 Mb
16-bit (low noise and high well capacity) RS 0.45 16-bit 30,000 10.5 Mb
Table 5: Typical performance of supported gain settings of the Zyla 4.2
AmplierGain
(Current Andor SDK / Solis description)
Mode
Sensitivity e
-
/
ADU (typical)
Data
Range
Eectivepixelsaturation
limit / e
-
Spooling File Size
(per frame)
12-bit (high well capacity) RS 7.5 12-bit 30,000 6.1 Mb
12-bit (low noise) RS 0.28 12-bit 1,100 6.1 Mb
16-bit (low noise and high well capacity) RS 0.45 16-bit 30,000 8.1 Mb
Figure 13: Highcontrastimageofxedlabelledcell.Intensitylineprolethroughsinglerowdemonstratespixelregionsthatwere
sampledbyhighgain(lownoise)andlowgain(highcapacity)ampliers.