PSB2163T-V31TR Infineon Technologies, PSB2163T-V31TR Datasheet - Page 137

• Manufacturer Part Number: PSB2163T-V31TR
• Description: IC AUDIO RINGING CODEC 28-PDSO
• Manufacturer: Infineon Technologies
• Series: ARCOFI®r

Specifications of PSB2163T-V31TR

• Function: CODEC Filter
• Interface: IOM-2, PCI, Serial
• Number Of Circuits: 1
• Voltage - Supply: 5V
• Current - Supply: 900µA
• Power (watts): 1mW
• Operating Temperature: -25°C ~ 80°C
• Mounting Type: Surface Mount
• Package / Case: DSO-28
• Includes: Activation and Deactivation, B-Channel and D-Channel HDLC Controllers, D-Channel Priority Handler, Monitor Channel Handler
• Lead Free Status / RoHS Status: Request inventory verification / Request inventory verification
• Other names: PSB2163T-V31INTR; PSB2163T-V31TR

Semiconductor Group
Electrical Feedbacks
There are various electrical couplings which cause attenuated echoes with and without
delays. Referring to figure 1, couplings exist in the hybrid where the 4/2-wire conversion
is realized, and at the interfaces between analog and digital transmission lines.
External to the telephone case in pure digital connections electrical feedbacks do not
exist, but large delays can result from digital processing in the exchanges. Additional
delays may be introduced e.g. by an intercontinental link or by links via satellites. Though
these delays are very annoying, it is not possible to eliminate them. Moreover, in every
speakerphone they can generate enormous problems.
At the near-end hybrid (A
in a range between 6 - 20dB. In the worst case it can decrease to just 6 dB. Due to the
relative small distance between the speakerphone system and the near-end hybrid, the
delay is negligible.
At the far-end hybrid the attenuation (A
but via the analog line inserted, additional loss may be introduced. The still more
annoying effect is that the echo returns to the loudspeaker with some non-negligible
delay.
side uses also a speakerphone system, an additional loss of 3dB is required. This loss
has always to be provided because it must be admitted that a speakerphone device is
connected at the far-end side.
HN
) the attenuation of the echo varies from one link to another
HF
) of the generated echo can also reach 6 dB,
136
Speakerphone Implementation