PEB2445NV1.2 Lantiq, PEB2445NV1.2 Datasheet - Page 10

• Manufacturer Part Number: PEB2445NV1.2
• Manufacturer: Lantiq

Specifications of PEB2445NV1.2

• Lead Free Status / Rohs Status: Supplier Unconfirmed

PEB 2445
Overview
The PCM samples of each input channel first pass through an input processing stage.
In this stage, an input attenuation level (0, 3, 6 or 9 dB) and a noise suppression
threshold can be programmed individually for each channel. Following the input
processing the PCM data is expanded according to the A- or -law encoding rules and
written to the Data Memory (DM). Additionally the PCM data of each input channel is
added to the Conference Sum Memory (CSM). The DM location (1 out of 64) is specified
by the Conference Control Address (CCA) and the CSM location (1 out of 21) is specified
by the conference number when writing to the Conference Control Memory (CCM).
The PCM data then passes through a substractor stage such that the resulting output
channel for a given subscriber contains the contribution of all the other channels in the
conference except its own. Finally the PCM data is forwarded to the output channel after
PCM compression and an optional output attenuation of 3 dB.
Attenuation
Attenuation is a new requirement for PBX switching systems. The purpose is to avoid
echo and noise problems on a PBX network for voice connections with access to the
public network. Further a certain loudness rating on a definite point for different terminals
and phones could be fixed (see figure 3).
Figure 3
Semiconductor Group
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