le7920 Zarlink Semiconductor, le7920 Datasheet - Page 15

• Manufacturer Part Number: le7920
• Description: Subscriber Line Interface Circuit
• Manufacturer: Zarlink Semiconductor

TEST CIRCUITS (continued)
100 kHz to 30 MHz
80% Amplitude
Modulated
1.5 Vrms
GEN
HF
V
S
R
L
50 Ω
= 600 Ω
Z
Return loss = –20 log (2 V
D
: The desired impedance;
e.g., the characteristic impedance of the line
R
R
L
L
2
1
E. Loop-Detector Switching
D. Two-Wire Return Loss Test Circuit
Z
A(TIP)
B(RING)
D
F. RFI Test Circuit
Zarlink Semiconductor Inc.
V
M
M
V
CC
/ V
200 Ω
200 Ω
S
15
)
Z
IN
DET
E1
6.2 kΩ
C
C
2
1
A(TIP)
B(RING)
SLIC
50 Ω
50 Ω
RF
RF
15 pF
AGND
2
1
VTX
R
SN
CAX
33 nF
CBX
33 nF
R
R
T1
T2
A
under test
B
R
SLIC
RX
VTX
C
T1