PEF2091 Siemens Semiconductor Group, PEF2091 Datasheet - Page 250

• Manufacturer Part Number: PEF2091
• Description: ICs for Communications(ISDN Echocancellation Circuit)
• Manufacturer: Siemens Semiconductor Group

Semiconductor Group
7.1.2
Note 70: The requirements for the power spectral density of the transmitted
Note 71: This change will be in force from January, 2000 onward. After this date
Figure 93
2B1Q signal on the U-interface has been changed by ETSI. This change
aims to reduce interference between basic rate 2B1Q signals on the one
hand and ADSL and VDSL signals on the other. All of these signals will
be transmitted on the same kind of lines in the future. For more
information, refer to the ETSI document “Technical Specification
101080" (1999).
To meet the new specification some modifications of the hybrid
recommended in previous IEC-Q versions are required. Figure 93 below
illustrates the hybrid circuit needed to meet these new ETSI
requirements.
systems with the old hybrid will not comply to ETSI standards at this
point.
U-Interface
U-Interface Hybrid Circuit
C
3.01 k
6.8 nF
681
k
619
619
10 k
10 k
24
24
250
10 k
10 k
22 nF
22 nF
22 nF
1:1.6
Application Hints
Data Sheet 01.99
PEB 2091
PEF 2091
1µF U