11

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Twisted Pair Driver

The high output current and low distortion, of the

CLC451, make it well suited for driving transformers.

Figure 13 illustrates a typical twisted pair driver utilizing

the CLC451 and a transformer. The transformer

provides the signal and its inversion for the twisted pair.

Figure 13: Twisted Pair Driver

s

s

Select the transformer so that it loads the line with a

frequency and can also affect the return loss. The return

loss, shown below, takes into account an ideal

CLC451’s maximum output voltage and current by:

From the above current relationship, it is obvious that an

amplifier with high output drive capability is required.

R

R

n

eq

L

2

=

Return Loss(dB)

20log

n

R

Z

10

2

o

o

≈−

⋅

Vn V

I

I

n

o

max

L

max

≤⋅

≤

+

-

UTP

1:n

V

n

4

AV

v in

=

V

-n

4

AV

v in

=

V

1n

2

AV

ov in

=

1

CLC451

7

6

8

5

3

4

2

1k

Ω

1k

Ω

0.1

µF

6.8

µF

+