<s>
A	O
constant	B-Algorithm
fraction	I-Algorithm
discriminator	I-Algorithm
(	O
CFD	O
)	O
is	O
an	O
electronic	O
signal	O
processing	O
device	O
,	O
designed	O
to	O
mimic	O
the	O
mathematical	O
operation	O
of	O
finding	O
a	O
maximum	O
of	O
a	O
pulse	O
by	O
finding	O
the	O
zero	O
of	O
its	O
slope	O
.	O
</s>
<s>
A	O
discriminator	B-Device
without	O
that	O
constant	O
fraction	O
would	O
just	O
be	O
a	O
comparator	O
.	O
</s>
<s>
(	O
namely	O
for	O
an	O
FM-demodulator	O
)	O
.	O
</s>
<s>
Often	O
the	O
logic	B-General_Concept
levels	I-General_Concept
are	O
shifted	O
from	O
-15	O
V	O
<	O
low	O
<	O
0	O
<	O
high	O
<	O
15	O
V	O
delivered	O
by	O
the	O
comparator	O
to	O
0	O
V	O
<	O
low	O
<	O
1.5	O
V	O
<	O
high	O
<	O
3.3	O
V	O
needed	O
by	O
CMOS	O
logic	O
.	O
</s>
<s>
If	O
the	O
discriminator	B-Device
triggers	O
a	O
sampler	O
with	O
a	O
following	O
comparator	O
this	O
is	O
called	O
a	O
single	O
channel	O
analyzer	O
(	O
SCA	O
)	O
.	O
</s>
