PSB21473FV13XT Infineon Technologies, PSB21473FV13XT Datasheet - Page 388

• 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

Data Sheet
expected acoustic level enhancement V. This level enhancement is divided into two
parts: G and GD. A block diagram of the SC is shown in figure 20-13.
Figure 20-13 Speech Comparator - Block Diagram
At both inputs, logarithmic amplifiers compress the signal range. Hence, only logarithmic
levels are on both paths and after the signals have been processed, logarithmic levels
on both paths are compared.
The main task of the comparator is to control the echo. The internal coupling due to the
direct sound and mechanical resonances is covered by G. The external coupling, mainly
caused by the acoustic feedback, is controlled by GD/PD. An example for direct sound
(1) and acoustic feedback (2) is illustrated in figure 20-14.
Figure 20-14 Speech Comparator - Acoustic Echoes
The base gain G corresponds to the terminal couplings of the complete telephone. Thus,
G is the measured or calculated level enhancement between the receive and the
transmit inputs of the SC.
SR
SX
Log. Amp.
Log. Amp.
Base Gain
G
2
1
Gain Reserve
388
GDN
GDS
Peak Decrement
Peak Decrement
PDS
PDN
PDS
PDN
Digital Signal Processor
PSB 21473
2003-03-31
INCA-D