Datasheet

Active Termination
3-5
THS6043EVM Applications
Now that the return impedance is corrected, forward voltage gain from input
to output is calculated. Equation 3 shows the simplified forward gain from
Vin to Vo.
(3)
A
V
+
V
O
"
V
in
"
+
1 )
ǒ
R
F
R
G
|| R
P
Ǔ
1–
ǒ
R
F
R
P
Ǔǒ
R
L
R
L
)R
S
Ǔ
iff R
L
tt R
P
Where:
R
L
+
R
LINE
2n
2
(4)
Where n is the turn ratio of the transformer.
The reader is cautioned that active termination is a very complex topic, with
many considerations. Carefully read the Texas Instruments application report
Active Output Impedance for ADSL Line Drivers, SLOA100 to gain a more
complete understanding of the topic and all of the subtle implications of active
termination.