Datasheet

Receive Path Implementation
3-6
3.3 Receive Path Implementation
Test points TP1 through TP4 are located on the EVM to facilitate the addition
of the receive signal path to the signal chain as shown in Figure 3−3. When
implementing the receive path, a hybrid must be used as ADSL is full duplex.
The hybrid cancels out the TX signal and allows the RX signal from the line to
come through. The THS6182DWEVM does not have receive or hybrid circuitry
included. Texas Instruments assumes that the customer has a proprietary
hybrid design, and therefore they would prefer to implement it. The user should
know their nominal line impedance characteristics and thus should be able to
match them better. Texas Instruments does have an EVM that contains a
THS6062 ADSL receiver, and this EVM can be purchased separately to
facilitate construction of a complete ADSL transmit/receive interface.
Figure 3−3. Implementation of the Receive Signal Path
4
3
2R
1
13
2
8
20
R2 = RF
R23=2 RG
R15 = Rs
TP1
C2
R3 = Rp
R6 = Rs
R12 = Rp
C1
+
−
U1B
THS6182
19
+V
R1
R10
Z1
R9
J2
Vin1
−V
+
−
U1A
THS6182
18
3
R11 = RF
R19
Z2 R18
J4
Vin2
TP4
1:n
TP2
Vout+
Line =
V Line
Vout−
Vo1
Vo
2
+V
−V
+
−
U2A
THS6062
8
5
6
+
−
U2B
THS6062
R
R
TP3
Vo2
2R
1
7
R
R
RX Vout+
RX Vout−
0 W 0 W
49.9 W
12.4 W
1.5 k W
2 k W
0.1 mF
750 W
2 k W
1.5 k W
12.4 W
0 W 0 W
49.9 W
100 W