Le7920
Data Sheet
TEST CIRCUITS (continued)
ZD
A(TIP)
VTX
RT1
R
SLIC
VS
VM
AGND
RSN
R
ZIN
CT1
RT2
B(RING)
Z : The desired impedance;
D
RRX
e.g., the characteristic impedance of the line
Return loss = –20 log (2 V / V )
M
S
D. Two-Wire Return Loss Test Circuit
VCC
6.2 kΩ
A(TIP)
DET
15 pF
RL = 600 Ω
B(RING)
E1
E. Loop-Detector Switching
C1
L1
200 Ω
200 Ω
50 Ω
A
B
RF1
CAX
33 nF
RF2
HF
50 Ω
CBX
33 nF
GEN
VTX
C2
L2
50 Ω
SLIC
under test
1.5 Vrms
80% Amplitude
Modulated
100 kHz to 30 MHz
F. RFI Test Circuit
15
Zarlink Semiconductor Inc.