PEF 20954 HT V1.1 Infineon Technologies, PEF 20954 HT V1.1 Datasheet - Page 19

• Manufacturer Part Number: PEF 20954 HT V1.1
• Description: IC ECHO CANCELLER DGTL TQFP144
• Manufacturer: Infineon Technologies

Specifications of PEF 20954 HT V1.1

• Function: Smart Integrated Digital Echo Canceller (SIDEC)
• Interface: PCM, Serial, UCC
• Number Of Circuits: 1
• Voltage - Supply: 3 V ~ 3.6 V
• Current - Supply: 350mA
• Power (watts): 900mW
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 144-LFQFP
• Includes: Double Talk Detection
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: PEF20954HTV1.1; SP000007505

Figure 5
Due to voice compression and error correction the one way transmission time for
wireless voice signals is typically 90 ms. With 180 ms roundtrip time the 50 ms roundtrip
time for echo free transmission is exceeded by at least 130 ms. Hence, the speaker on
the mobile phone will hear any kind of echo generated in the hybrid next to the POTS or
the acoustical echo of the POTS. The SIDEC suppresses those two kinds of echoes if it
is incorporated in the MSC. Depending on the individual call the end echo path can differ
dramatically. In Europe the end echo path could even go to different countries causing
strong dispersion of the echo. Only a high quality echo canceller with long end path delay
options guarantees compensation of the strongly varying echoes.
Data Sheet
POTS
POTS
POTS
POTS
Echo
SIDEC in a Wireless System
E1/T1
TRAU:
MSC:
SIDEC
Transcoder Rate Adaptor Unit
Mobile Switching Center
MSC
TRAU
19
TRAU
BTS
BSC:
BTS:
Base Station Controller
Base Transceiver Station
BSC
round trip time: 180 ms
BTS
BTS
SIDEC in a WL System
Rev. 2, 2004-07-28
Introduction
PEB 20954
PEF 20954
BTS