PEB3265 Infineon Technologies Corporation, PEB3265 Datasheet - Page 50

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

Preliminary
Figure 23
3.4.1
The current sense signal (ITAC) is converted to a voltage by an external resistor. This
voltage is first filtered by an anti-aliasing filter (pre-filter), that stops producing noise in
the voiceband from signals near the A/D sampling frequency. A/D conversion is done by
a 1-bit sigma-delta converter. The digital signal is down-sampled further and routed
through programmable gain and filter stages. The coefficients for the filter and gain
stages can be programmed to meet specific requirements. The processed digital signal
goes through a compander (CMP) that converts the voice data into A-law or -law codes.
A time slot assignment unit outputs the voice data to the programmed time slot.
SLICOFI-2x can also operate in 16-bit linear mode for processing uncompressed voice
data. In this case, two time slots are used for one voice channel.
3.4.2
The digital input signal is received via the IOM-2 or PCM interface. Expansion (EXP),
PCM low-pass filtering, frequency response correction and gain correction are
performed by the DSP. The digital data stream is up-sampled and converted to a
corresponding analog signal. After smoothing by post-filters in the SLICOFI-2x, the AC
signal is fed to the SLIC, where it is superimposed on the DC signal. The DC signal has
been processed in a separate DC path. A TTX signal, generated digitally within
SLICOFI-2x, can also be added.
Data Sheet
Transmit Path
Receive Path
Signal Flow in Voice Channel (A)
ACP
ACN
ITAC
SLICOFI-2x
Channel B
TTX
filter
Impedance
matching
+
Channel A
Pre-
filter
Post-
filter
Teletax
generator
D/A
A/D
Impedance
matching
+
50
Amplify
transmit
receive
Amplify
Transhybrid
filter
+
Frequency
response
transmit
Transmit
Frequency
response
Receive
receive
Functional Description
+
CID generation
CMP
TG 1
EXP
DTMF detection
TG 2
PCM out
PCM in
ezm14026.emf
2000-07-14
DuSLIC