® 8k/4k CL
30
UM 8k/4k CL – REVA – 01/13
e2v semiconductors SAS 2013
6.3.4
Gain and Offset
Analog Gain in the ADC
The only analog Gain available in
the is located at the
sensor level, in the ADC
converter.
This “Preamp Gain” is in fact a
variation of the ramp of the
comparator of the ADC.
Then 3 Values are available :
x1, x2 and x4
•
Preamp Gain
: (
Gain
with
GainSelector
=
AnalogAll
)
Set the Pre-amplification Gain
.
This command is available in the CommCam “Gain & Offset” section.
Read function : “
r pamp
”;
Returned by the camera : Integer corresponding to one of the 3 different step values :
•
0 : x1 (0dB)
•
1 : x2 (6dB)
•
2 : x4 (12dB)
Write function : “
w pamp
” <int> ;
x4
x2
x1
LSB
255
1024
Comparator Ramps
at different
Gains
Clamp (Black Ref)
Setting
512
10 bits
conversion
8 bits
conversion
Value issued
from the Pixel
OUT
Pixel
X
Preamp
Gain
X
Amp
Gain
+
X
FFC
Offset Gain
X
FFC
Adjust
+
X
LUT
or
Contrast Exp
.
Offset Gain
FPGA
Sensor
X
Sensor
Tap
Gains
Action on whole line
Action per pixel
Action per Sensor’s Tap