e-stlc3095 STMicroelectronics, e-stlc3095 Datasheet - Page 14

• Manufacturer Part Number: e-stlc3095
• Description: Integrated Pots Interface For Home Gateway And Wll
• Manufacturer: STMicroelectronics

Functional description
3.2.4
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Once in Active mode (D1=1) the SLIC can operate in different states setting properly D0 and
D2 control bits (see also
Table 8.
Polarity reversal
The D2 bit controls the line polarity, the transition between the two polarities is performed in
a “soft” way. This means that the TIP and RING wire exchange their polarities following a
ramp transition (see
The transition time is controlled by an external capacitor CREV. This capacitor also sets the
shape of the ringing trapezoidal waveform. When the control pins set battery reversal the
line polarity is reversed with a proper transition time set via an external capacitor (CREV).
Figure 5.
Ringing
When this mode is selected the STLC3095 self generates an higher negative battery (-64V
typ.) in order to allow a balanced ringing signal of typically 59Vpeak.
In this condition both the DC and AC feedback loops are disabled and the SLIC line drivers
operate as voltage buffers. The ring waveform is obtained toggling the D2 control bit at the
desired ring frequency. This bit controls the line polarity (0=direct; 1= reverse).
As in the ACTIVE mode the line voltage transition is performed with a ramp transition,
creating a trapezoidal balanced ring waveform (see
The shaping is defined by the CREV external capacitor.
D0
0
0
Input impedance synthesis: can be real or complex and is set by a scaled (x50 or
x25) external ZAC impedance.
Transmit and receive: The AC signal present on the 2W port (TIP/RING) is transferred
to the TX output with a -6dB or -12dB gain and from the RX input to the 2W port with a
0dB or +6dB gain.
2 to 4 wire conversion: The balance impedance can be real or complex, the proper
cancellation is obtained by means of two external impedance ZA and ZB
D1
SLIC states in ACTIVE mode
TIP/RING typical transition from direct to reverse polarity
1
1
Figure 5
D2
0
1
Table 8
GND
TIP
RING
Active Normal Polarity
Active Reverse Polarity
).
).
dV/dT set
by CREV
4V typ.
Figure 6
Operating mode
38 V typ
ON-HOOK
).
STLC3095