PSB 21373 H V1.1 Infineon Technologies, PSB 21373 H V1.1 Datasheet - Page 131

• Manufacturer Part Number: PSB 21373 H V1.1
• Description: IC SPEECH AND VOICE MQFP-44
• Manufacturer: Infineon Technologies
• Series: SCOUT™r

Specifications of PSB 21373 H V1.1

• Function: CODEC
• Interface: IOM-2, SCI
• Number Of Circuits: 1
• Voltage - Supply: 5V
• Current - Supply: 97.5mA
• Mounting Type: Surface Mount
• Package / Case: 44-BQFP
• Includes: Activation and Deactivation, Channel Handler, DTMF / Tone / Ringing Generator, HDLC Controller, Speakerphone, Voice Monitoring
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power (watts): -
• Operating Temperature: -
• Other names: PSB21373HV1.1XT; PSB21373HV11XT; SP000007602

PSB 21373
Figure 67
Speech Comparator at the Line Side
The Gain of the Line Echo (GLE) directly corresponds to the echo return loss of the link.
Generally, it is specified to 27 dB. However, the worst case loss can be estimated to
10 dB. This means, the echo returns at least attenuated by 10 dB.
Similarly to the acoustic side, GDLE at the line side features the reserve above GLE
which is necessary to control the echo via the decrement PDLE. GDLE and PDLE are
t
interdependent. Exactly
[ms] after the end of RX-speech the level enhancement VLE
must be at least GLE to prevent clipping.
Two pairs of coefficients are available: GDSLE/PDSLE while speech is detected and
GDNLE/PDNLE in case of noise. This offers the possibility to control separately the far-
end echo during speech and the near-end echo while noise is detected. However, this
requires an attenuation between the speech detectors SDX and SDR: If the SDX does
not recognize any speech, the SDR must not detect speech due to the far-end echo.
Note, that LIMX and LIMR are also influencing the sensitivity of the speech detection.
ETLE [ms] after the final speech detection the parameter sets are switched. If both sets
are equal, ETLE has no meaning.
Data Sheet
131
2002-05-13