MT9300B Ver la hoja de datos (PDF) - Zarlink Semiconductor Inc
Número de pieza
componentes Descripción
Lista de partido
MT9300B Datasheet PDF : 39 Pages
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MT9300B
Data Sheet
Sin
echo
path A
Rout
PORT2
echo
path B
channel A
+
-
Adaptive
Filter (64 ms)
channel A
E.C.A
Optional -12dB pad
channel B
+
-
Adaptive
Filter (64 ms)
channel B
E.C.B
Optional -12dB pad
a) Normal Configuration (64 ms)
Sout
Rin
PORT1
channel A
Sin
+
Sout
-
echo
path A
Adaptive Filter
(128 ms)
Rout
PORT2
channel A
E.C.A
Optional -12dB pad
Rin
PORT1
b) Extended Delay Configuration (128ms)
Sin
echo
path
Rout
PORT2
+
-
Optional -12dB pad
Adaptive
Filter (64 ms)
Adaptive
Filter (64 ms)
-
+
E.C.A Optional -12dB pad E.C.B
Sout
echo
path
Rin
PORT1
c) Back-to-Back Configuration (64 ms)
Figure 6 - Device Configuration
Narrow Band Signal Detector (NBSD)
Single or dual frequency tones (i.e., DTMF tones) present in the receive input (Rin) of the echo canceller for a
prolonged period of time may cause the Adaptive Filter to diverge. The Narrow Band Signal Detector (NBSD) is
designed to prevent this by detecting single or dual tones of arbitrary frequency, phase, and amplitude. When
narrow band signals are detected, adaptation is halted but the echo canceller continues to cancel echo.
The NBSD can be disabled by setting the NBDis bit to “1” in Control Register 2.
Offset Null Filter
Adaptive filters in general do not operate properly when a DC offset is present at any inputs. To remove the DC
component, the MT9300B incorporates Offset Null filters in both Rin and Sin inputs.
The offset null filters can be disabled by setting the HPFDis bit to “1” in Control Register 2.
ITU-T G.168 Compliance
The MT9300B has been certified G.168 compliant in all 64 ms cancellation modes (i.e. Normal and Back-to-Back
configurations) by in-house testing with the DSPG ECT-1 echo canceller tester.
It should be noted that G.168 compliance is not claimed for the 128 ms Extended Delay mode, although
subjectively no difference can be noticed.
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Zarlink Semiconductor Inc.
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