PEF 20954 HT V1.1 Infineon Technologies, PEF 20954 HT V1.1 Datasheet - Page 70

• 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

4.4
This sections shows you the correlation of the different SIDEC configuration registers
settings with the SIDEC operational functions and the effect of the settings on these
functions.
For further explanation or the exact values please refer to the detailed register
description.
4.4.1
The following tables give some more insight on the configuration options of the adaptive
filters.
4.4.1.1
Table 28
Register Addr. Value
AEEPD
ACONF
The transversal filter can be modified in length (amount of taps) and maximum coefficient
value / granularity.
ACONF.EMAF set to 1 results in an additional attenuation of the artificial by 6 dB, thus
the values of the coefficients are in bigger and the echo filter model more accurate.
4.4.1.2
Table 29
Register Addr. Value
AFSTC
Data Sheet
72H
79H
71H
Operational functions configuration
Adaptive filter function
Filter
Filter coefficient Adaptation Speed
Filter Parameter
Filter coefficient adaptation speed adjustment
DELAY
ACSPT Up
EMAF
CSPT
Mod.
Up
Down
Mod.
Up
Down decrease the (end echo path) filter length
0
1
Effect
increase the (end echo path) filter length
SIDEC works up to 0 dB echo attenuation
SIDEC works up to 6 dB echo attenuation,
granularity of the filter is doubled, quality of
artificial echo better
Effect
decrease damping effect on aux. coef.,
convergence speed "Up", stability "Down"
increase damping effect on aux. coef.,
convergence speed "Down", stability "Up"
decrease damping effect on main coef.,
convergence speed "Up", stability "Down"
70
Operational Description
Rev. 2, 2004-07-28
PEB 20954
PEF 20954