TYPICAL APPLICATION

Line Interface - Differential Duplexor

22k

W

22k

W

100pF

VCM

22k

W

22k

W

100pF

680pF

13.2k

W

13.2k

W

OUT-

OUT+

C'

1.2k

W

1.2k

W

2.2nF

VCM

2.2nF

C

2R

Z0/2

C

2R

Z0/2

R

R

Phone

Line

C : Improve the low frequency response.

Its value depends on the transformer inductance.

C' : Reduces the DC offset gain.

Z0 : Nominal line impedance

IN+

IN-

R'

r

R'

Figure 10

All capacitor, resistor and impedance values are provided for indication only. These values must be

readjusted according to line transformer characteristics and also telecommunication regulations in force in

individual countries.

Refer to Application Note AN930 for more detailed information. Contact your local representative.

STLC7550

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