PSB4860HV4.1 Lantiq, PSB4860HV4.1 Datasheet - Page 29

• Manufacturer Part Number: PSB4860HV4.1
• Manufacturer: Lantiq

Specifications of PSB4860HV4.1

• Lead Free Status / Rohs Status: Supplier Unconfirmed

2.1
In this section the functional units of the are described in detail. The functional units can
be individually enabled or disabled.
2.1.1
The speakerphone unit (figure 11) is attached to four signals (microphone, loudspeaker,
line out and line in). The two input signals (microphone, line in) are preceded by signal
summation points.
Figure 11 Speakerphone - Signal Connections
Internally, this unit can be divided into an echo cancellation unit and an echo suppression
unit (figure 12). The echo cancellation unit provides the attenuation G
suppression unit provides the attenuation G
speakerphone is therefore ATT=G
Figure 12 Speakerphone - Block Diagram
The echo cancellation unit estimates that part of the signal at the microphone that
originates from the loudspeaker. This part is then subtracted from the signal at the
microphone. This technique allows a full-duplex speakerphone.
Data Sheet
loudspeaker
microphone
S
11
I
I
1
2
Functional Units
Full Duplex Speakerphone
loudspeaker
microphone
Cancellation
o
u
d
a
c
s
c
s
e
Echo
t
i
i
G
c
Speakerphone
C
+G
s
.
29
s
. The total attenuation ATT of the
n
e
s
d
e
l
i
i
Suppression
Echo
G
line out
line in
S
c
while the echo
PSB 4860
S
I
I
line out
line in
3
4
12
2000-01-14