14

Am79574 Data Sheet

TEST CIRCUITS

VTX

RSN

AGND

RSN

AGND

VTX

A. Two- to Four-Wire Insertion Loss

B. Four- to Two-Wire Insertion Loss and Balance Return Signal

VTX

RSN

AGND

S2 Open, S1 Closed:

SLIC

SLIC

SLIC

SLIC

2

B(RING)

A(TIP)

B(RING)

A(TIP)

S1

B(RING)

A(TIP)

S2

1/

ωC << R

L

C

S2 Closed, S1 Open:

C. Longitudinal Balance

R

R

900

Ω

B(RING)

A(TIP)

RSN

AGND

VTX

D. Two-Wire Return Loss Test Circuit

Note:

characteristic impedance of the line).

IDC

2

2

2