PEB3265 Infineon Technologies Corporation, PEB3265 Datasheet - Page 59

• Manufacturer Part Number: PEB3265
• Description: (PEB326x / PEB426x) Dual Channel Slicofi-2 / Slic Duslic
• Manufacturer: Infineon Technologies Corporation

Preliminary
In both balanced and unbalanced ringing modes, SLICOFI-2 automatically applies and
removes the ringing signal during zero-crossing. This reduces noise and cross-talk to
adjacent lines.
3.5.7
SLICOFI-2x supports external ringing for higher unbalanced ringing voltage
requirements above 85 Vrms with all SLICs. For a detailed application diagram of
unbalanced ringing see
Since high voltages are involved, an external relay should be used to switch the RING
line off and to switch the external ringing signal together with a DC voltage to the line.
The DC voltage has to be applied for the internal ring trip detection mechanism which
operates for external ringing in the same way as for internal ringing.
The SLICOFI-2x has to be set to the external ringing mode by the REXT-EN bit in
register BCR2. A synchronization signal of the external ringer is applied to the
SLICOFI-2x via the RSYNC pin. The external relay is switched on or off synchronously
to this signal via the IO1 pin of the SLICOFI-2x according to the actual mode of the
DuSLIC. An interrupt is generated if the DC current exceeds the programmed ring trip
threshold.
3.6
Signaling in the subscriber loop is monitored internally by the DuSLIC chip set.
Supervision is performed by sensing the longitudinal and transversal line currents on the
Ring and Tip wires. The scaled values of these currents are generated in the SLIC and
fed to the SLICOFI-2x via the IT and IL pins.
Transversal line current:
Longitudinal line current:
where
Off-hook Detection
Loop start signaling is the most common type of signaling. The subscriber loop is closed
by the hook switch inside the subscriber equipment.
• In Active mode, the resulting transversal loop current is sensed by the internal current
Data Sheet
sensor in the SLIC. The IT pin of the SLIC indicates the subscriber loop current to the
SLICOFI-2x. External resistors (
current information to a voltage on the ITA (or ITB) pin.
The analog information is first converted to a digital value. It is then filtered and
processed further which effectively suppresses line disturbances. If the result exceeds
a programmable threshold, an interrupt is generated to indicate off-hook detection.
I
R
,
I
T
External Unbalanced Ringing
Signaling (Supervision)
are the loop currents on the Ring and Tip wires.
Figure 100
I
I
TRANS
LONG
= (
= (
I
I
R –
R
and
R
IT1
+
I
T
I
,
Figure 101
T
)/2
)/2
R
59
IT2,
see
Figure
on
Page 372
97,
Functional Description
Page
and
368) convert the
Page
373.
2000-07-14
DuSLIC