PEB3265 Infineon Technologies Corporation, PEB3265 Datasheet - Page 53

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

Preliminary
ringer period. This causes the integration result to represent the DC component of the
ring current. If the DC current exceeds the programmed ring trip threshold, SLICOFI-2x
generates an interrupt. Ring trip is reliably detected and reported within two ring signal
periods. The ringing signal is switched off automatically at zero crossing by the
SLICOFI-2x. The threshold for the ring trip DC current is set internally in SLICOFI-2x,
programmed via the digital interface. The DC offset for ring trip detection can be
generated by the DuSLIC chip set and the internal ring trip function can be used, even if
an external ringing generator is used.
AC Ring Trip Detection
For short lines (< 1 k loop length) and for low-power applications, the DC offset can be
avoided to reduce the battery voltage for a given ring amplitude. Ring trip detection is
done by rectifying the ring current I
comparing it to a programmable AC ring trip threshold. If the ring current exceeds the
programmed threshold the HOOK bit in register INTREG1 is set accordingly.
Most applications with DuSLIC are using DC ring trip detection, which is more reliable
than AC ring trip detection.
3.5.3
There are two methods of ringing:
• Balanced ringing (bridged ringing)
• Unbalanced ringing (divided ringing)
Internal balanced ringing generally offers more benefits compared to unbalanced
ringing:
• Balanced ringing produces much less longitudinal voltage, which results in a lower
• By using a differential ringing signal, lower supply voltages become possible
The phone itself cannot distinguish between balanced and unbalanced ringing. Where
unbalanced ringing is still used, it is often simply a historical leftover. For a comparison
between balanced and unbalanced ringing see also ANSI document T1.401-1993.
Additionally, integrated ringing with the DuSLIC offers the following advantages:
• Internal ringing (no need for external ringing generator and relays)
• Reduction of board space because of much higher integration and fewer external
• Programmable ringing amplitude, frequency and ringing DC offset without hardware
• Programmable ring trip thresholds
• Switching off the ringing signal at zero-crossing
Data Sheet
amount of noise coupled into adjacent cable pairs
components
changes
Ringing Methods
TRANS
53
, integrating it over one ringer period and
Functional Description
2000-07-14
DuSLIC