PEB2465H View Datasheet(PDF) - Infineon Technologies

Part Name

Description

Manufacturer

PEB2465H

4-channel codec filter

Infineon Technologies 

SICOFI-4

PEB 2465

Functional Description

Transmit Path

The analog input signal has to be DC-free connected by an external capacitor because

there is an internal virtual reference ground potential. After passing a simple antialiasing

prefilter (PREFI) the voice signal is converted to a 1-bit digital data stream in the Sigma-

Delta-converter. The first downsampling steps are done in fast running digital hardware

filters. The following steps are implemented in the micro-code which has to be executed

by the central Digital Signal Processor. This DSP-machine is able to handle the workload

for all four channels. At the end the fully processed signal (flexibly programmed in many

parameters) is transferred to the IOM-2 interface in a PCM-compressed signal

representation.

Receive Path

The digital input signal is received via the IOM-2 interface. Expansion, PCM-Law-pass-

filtering, gain correction and frequency response correction are the next steps which are

done by the DSP-machine. The upsampling interpolation steps are again processed by

fast hardware structures to reduce the DSP-workload. The upsampled 1-bit data stream

is then converted to an analog equivalent which is smoothed by a POST-Filter (POFI).

As the signal VOUT is also referenced to an internal virtual ground potential, an external

capacitor is required for DC-decoupling.

Loops

There are two loops implemented. The first is to generate the AC-input impedance (IM)

and the second is to perform a proper hybrid balancing (TH). A simple extra path IM2

(from the transmit to the receive path) supports the impedance matching function.

Test Features

There are four analog and five digital test loops implemented in the SICOFI-4. For

special tests it is possible to ‘Cut Off’ the receive and the transmit path at two different

points.

Data Sheet

17

2000-02-08

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