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DESCRIPTION

ST70134 is the Analog Front End of the STMicroelectronics

ASCOTTM ADSL chipset and when

coupled with ST70135A or ST70235 (DMT

modem) allows to get a T1.413 Issue 2 or G.dmt

compliant solution.

The ST70134 analog front end handles 2 transmission

channels on a balanced 2 wire interconnection;

a 16 to 640Kbit/s upstream transmit

channel and a 1.536Mbit/s to 8.192Mbit/s downstream

receive channel.

This asymmetrical data transmission system uses

high resolution, high speed analog to digital and

digital to analog conversion and high order analog

filtering to reduce the echo and noise in both

receivers and transmitters.

External low noise driver and input stage used

with ST70134 guarantee low noise performances.

The filters, with a programmable cutoff frequency,

use automatic Continuous Time Tuning to avoid

time varying phase characteristic which can be of

dramatic consequence for DMT modem.

It requires few external components, uses a 3.3V

supply. It is packaged in a 64-pin TQFP in order to

reduce PCB area.