Instruction manual
Guppy Technical ManualV7.4.0
91
Description of the data path
White balance does not use the so-called PxGA® (Pixel Gain Amplifier) of the
analog front end (AFE) but a digital representation in the FPGA in order to mod-
ify the gain of the two channels with lower output by +9.5 dB (in 512 steps) rel-
ative to the channel with highest output.
The following screenshot is taken from the datasheet of the AFE and illustrates
the details:
The analog color signal, coming in pulse amplitude modulation from the sensor,
is in the form of the BAYER™ color pattern sequence. It is initially processed in
the CDS (correlated double sampler) then bypasses the PxGA before further
amplification and digitization.
Figure 55: Block diagram of AFE (Source: Analog Devices)