CPC5620/CPC5621
2. Application Circuits
LITELINK can be used with telephone networks
worldwide. Some public telephone networks, notably
in North America and Japan require resistive line
termination. Other telephone networks, as in Europe
and elsewhere, require a reactive line termination.
The application circuits below address both line
termination models. The reactive termination
application circuit
describes the
TBR-21 implementation. This circuit can be adapted
easily for other reactive termination needs.
2.1 Resistive Termination Application Circuit
Figure 3. Resistive Termination Application Circuit Schematic
3.3 or 5V
R23
2
10
C16
10μ
A
C1
1μ
FB1
600 Ω
200 mA
A
U1
R1
(R
TX
)
80.6K
C13
C2
0.1μ
0.1μ
1 VDD
2 TXSM
3 TX-
4 TX+
5 TX
6 MODE
A
LITELINK
REFL 32
TXF
ZTX
ZNT
TXSL
BR-
31
30
29
28
27
C9
0.1μ
BR-
TX-
TX+
R5
(R
TXF
)
60.4K
BR-
R75
(R
NTX
)
261K
7 GND
8 OH
9 RING
10 CID
NTS 26
GAT 25
NTF
24
R12
(R
NTF
)
499K
R15
(R
DCS2
)
1.69M
R16 (R
3
ZDC
)
8.2
BR-
R76 (R
HTF
)
200K
R8 (R
221K
HTX
)
BR-
C10
0.01μ
500V
R13
(R
NTS
)
1M
R22
(R
DCS1A
)
6.49 M
R21
(R
DCS1B
)
6.49M
C12
(C
DCS
)
0.027μ
BR-
OH
RING
CID
RX-
RX+
C14
C4
R14
(R
GAT
)
47
5%
Q1
CPC5602C
C15
0.01μ
500V
BR-
C21
100p
(C
GAT
)
DCS1 23
DCS2
22
0.1μ 11
RX-
0.1μ 12
RX+
13 SNP+
14 SNP-
15 RXF
16 RX
R2
(R
RXF
)
130K
ZDC 21
BR- 20
RPB
RXS
VDDL 17
19
18
R20
(R
VDDL
)
2
5%
+
DB1
TIP
-
R18
(R
ZTX
)
3.32K
BR-
BR-
R4
(R
PB
)
68.1
BR-
C18
15p
3
R10
(R
ZNT
)
301
BR-
SP1
1
RING
C7
(C
SNP-
)
4
220pF
R3
(R
SNPD
)
1.5M
C8
(C
SNP+
)
4
220pF
R6
(R
SNP-2
)
1.8M
R7
(R
SNP+2
)
1.8M
R44
(R
SNP-1
)
1.8M
R45
(R
SNP+1
)
1.8M
NOTE: Unless otherwise noted:
Resistor values are in Ohms
All resistors are 1%.
Capacitor values are in Farads.
¹This design was tested and found to comply with FCC Part 68 with this
Sidactor. Other compliance requirements may require a different part.
²Higher-noise power supplies may require substitution of a 220
μH
inductor,
Toko 380HB-2215 or similar. See the Power Quality section of Clare
application note AN-146,
for
more information.
³Optional for enhanced transhybrid loss.
4
Use
voltage ratings based on the isolation requirements of your application.
6
www.clare.com
R04
CLARE [ CLARE, INC. ]
