PSB21473FV13XT Infineon Technologies, PSB21473FV13XT Datasheet - Page 395

• Manufacturer Part Number: PSB21473FV13XT
• Manufacturer: Infineon Technologies

Specifications of PSB21473FV13XT

• Operating Supply Voltage (typ): 3.3V
• Operating Supply Voltage (min): 3.135V
• Operating Supply Voltage (max): 3.6V
• Operating Temp Range: 0C to 70C
• Operating Temperature Classification: Commercial
• Mounting: Surface Mount
• Pin Count: 144
• Lead Free Status / RoHS Status: Compliant

1.
2.
With the first condition, adaption to small signals can be avoided. The second condition
avoids adaption during double talk. The parameter ATT represents the echo loss
provided by external circuitry. The adaption stops if the power of the received signal (I2)
exceeds the power of the expected signal (I1-ATT) by more than the margin MGN.
Figure 20-18 Line Echo Cancellation Unit - Superior Mode with Shadow FIR
The basic idea of the superior mode is shown in figure 20-18. The shadow FIR filter on
the left hand side gets its coefficients adapted similarly to the adaptive filter of the Line
Echo Canceller in normal mode. For cancelling the line echo, however, the FIR filter on
the right hand side is used. When the quality of this FIR filter is excelled by the quality of
the shadow FIR filter, the coefficients of the shadow FIR filter are copied to the FIR on
the right hand side. More formally, the coefficients of the shadow FIR filter are adapted
if similar to normal mode, the following two conditions hold:
1.
2.
In this case, ATT is already the difference between external echo loss and margin
(ATT
normal mode. The parameter ATT should be adjusted accordingly. Note that ATT can
now be negative.
The coefficients are copied from the shadow FIR filter to the actually used FIR filter if
1. currently the adaption of the shadow FIR filter is in progress
and at least one of the following two conditions holds:.
Data Sheet
I
2
I1 MIN
I1 I2
I1 MIN
I1 I2
superior
–
–
Shadow
–
–
Filter
FIR
ATT
ATT
= ATT
+
MGN
0
normal
- MGM
0
adapt
coeff.
normal
) so that the condition is actually the same as for
395
copy
coeff.
Digital Signal Processor
Filter
-
FIR
+
PSB 21473
2003-03-31
INCA-D
S
I
1
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