MTC20154-TQ-C2 ST Microelectronics, Inc., MTC20154-TQ-C2 Datasheet - Page 9

• Manufacturer Part Number: MTC20154-TQ-C2
• Description: Integrated Adsl CMOS Analog Front-end Circuit
• Manufacturer: ST Microelectronics, Inc.

ATU-C Side Block Diagram
The transformer at the ATU-C side has a 1:2 ratio. The termination resistors are 12.5Ω in case of 100Ω
lines. The hybrid bridge resistors should be < 2.5 kΩ for low-noise.
An HP filter must be used on the TX path to reduce DMT sidelobes and out-of-band noise influence on the
receiver.
On the RX path, a LP filter must be used in order to reduce the echo signal level and to avoid saturation
of the input stage of the receiver.
The POTS filter is used in both directions to reduce crosstalk between ADSL signals and POTS speech
and signalling.
Figure 4. ATU-C AFE Schematics (For detailed schematics see MTB-20150-EBC reference design.)
RXT1
Pots Filter
line driver
Gtx
RXT2
H
P
F
Pots Filter
RXN [0:1]
POTS
RXP [0:1]
LP
TXP
TXN
P
F
L
-15.. 31db
-g..+6db
LNA
P. D .
VCODAC
MTC-20154
LP 138 KHz
LP 1.1 MHz
35.328 MHz or 17.664 MHz
VCXO
Master clock 35.328 MHz
Word 8.832/4.416 MHz
convertor
convertor
Nibbles 17.664 MHz
D/A
D/A
13bits
8.832 MS/s
4.416 MS/s
12bits
8.832 MS/s
4.416 MS/s
LTNT=1
RESETN
CTRLIN
4
4
MTC20154
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