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TA0313

STMicroelectronics Solutions for ADSL Line Interfaces

The line interface - ADSL remote terminal (RT)

Figure 2 shows a typical analog line interface used for ADSL. The upstream and downstream signals are

separated from the telephone line by using an hybrid circuit and a line transformer. On this note,

emphasis will be placed on the emission path.

The emission path

The features of the TS613 and TS612 drivers are shown in Table 1 below.

In order to shrink the line interface size, the TS613 comes in the classic SO8 plastic package as well as

the SO8 ExposedPAD plastic package, capable of dissipating 1.7W at room temperature. While this

circuit does not feature a power-down function, it does have the advantage of featuring a standard pin-

out.

Figure 2: Typical ADSL Line Interface

Table 1: Features of drivers

GBP

(MHz)

BW

Gain=4

MHz)

SR

(V/µs)

Iout typ.

(mA)

Noise

(

nV/

√Hz)

Icc per

op.

(mA)

(dBc)

1) Single ended 4Vpp/100kHz on 25

Ω//15pF

Vout

diff.

(Vpp

min)

Packages

TS613

VFA

130

34

40

320

3

11

74/79

18

SO8

SO8 Exposed Pad

TS612

VFA

130

34

40

320

3

14

74/79

18

SO20 Batwing

HYBRID

POTS

SPLITTER

line

TRANSMISSION

RECEPTION

TS613

TS612

AFE

25

Ω

12.5

Ω

TX

RX

DMT

12.5

Ω

HYBRID

POTS

SPLITTER

line

TRANSMISSION

RECEPTION

TS613

TS612

AFE

25

Ω

12.5

Ω

TX

RX

DMT

12.5

Ω