MTC-20144TQ-I AMI Semiconductor, Inc., MTC-20144TQ-I Datasheet - Page 13

• Manufacturer Part Number: MTC-20144TQ-I
• Description: Integrated ADSL CMOS Analog Front-End Circuit
• Manufacturer: AMI Semiconductor, Inc.

TX Pre-driver Capability
The pre-driver drives an external line
power amplifier which transmits the
required power to the line.
TX Filter
The TX filters act not only to suppress the
DMT sidebands but also as smoothing
filters on the D/A convertor’s output to
suppress the image spectrum. For this
reason they are realised in a time
continuous approach.
ATU_R-TX Filter
The purpose of this filter is to remove
out-of-band noise of the ATU_R-TX path
echoed to the ATU_R-RX path. In order
to meet the transmitter spectral response,
an additional filtering is (digitally)
performed. The integrated filter has the
following nominal characteristics :
Phase characteristic:
Note: The total TX path (including
DAC) group delay distortion is 8 µs
TX drive level to the external line driver for max AGC setting
External line driver input impedance :
Pre-driver characteristics :
closed loop gain :
output offset voltage (0 dB) :
input noise voltage (0 dB):
output common mode voltage :
Description
Input refered noise
Max. input level
Max. output level
Type
Frequency band
Frequency tuning
Max. in-band ripple
Description
Total RX filter group delay
Total RX filter group delay distortion
ATU_C-TX Filter
Same filter as ATU_R-RX. Its purpose is
now is to remove image frequency of
the transmitted signal according the
ANSI definition.
13
resistive
capacitive
-15dB...0 dB with step=1dB
<10 mV
<20 nVHz- 1/2 @ f > 250k
<50 nVHz -1/2 @ 34.5k<f< 138k
1.6V < Vcm < 1.7V
Value/Units
220 nV/Hz
1 Vpd
1 Vpd
4th order chebychef
138 KHz (f0)
f0/1.23 -> 1.25*f0
1 dB
Value/Units
<50 us
<8 us
1/2
@ 34.5kHz < f < 138kHz
@ 34.5kHz < f < 138kHz
MTC-20144
1.5 Vpdif
>500Ω
<30pF