PSB 2134 H V2.2 Infineon Technologies, PSB 2134 H V2.2 Datasheet - Page 79

• Manufacturer Part Number: PSB 2134 H V2.2
• Description: IC CODEC FILTER 4CHAN MQFP-64
• Manufacturer: Infineon Technologies
• Series: SICOFI®r

Specifications of PSB 2134 H V2.2

• Function: CODEC Filter
• Interface: IOM-2 PCM, SPI
• Number Of Circuits: 4
• Voltage - Supply: 5V
• Current - Supply: 26mA
• Power (watts): 130mW
• Mounting Type: Surface Mount
• Package / Case: 64-QFP
• Includes: Level Metering Function, Tone Generation
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Operating Temperature: -
• Other names: PSB2134HV2.2X; SP000007389; SP000007390

The TAS 2100 emulates subscriber line lengths from 0 to 6 kft in 1 kft increments. 1 kft
is equivalent to 0.3 km.
The SICOFI2/4-TE is programmed with the file TEST.SUC for operation with the
Harris-SLIC HC 5502 and the specification for Germany. The file TEST.SUC is a
component part of the QSICOS software.
After that the SICOFI2/4-TE is programmed with the file LMch1b.SUC of appendix C.
The task of this file is to program the bandpass filters at 1516 Hz and to increase the
amplification by programming the AR and AX filters. With the second part of the file
LMch1b.SUC the Level Metering Function is activated and the offset register is loaded.
The read command reads out CR2 with bit LMR. Bit LMR shows if the level detected is
higher or lower than the reference stored in the offset register.
By changing the line length with the Loop Emulator the levels of appendix D are
measured by using the procedure described in paragraph 2.1. The values of the metered
levels are depending on the line lengths.
That means, that it is possible to determine the state of a connected telephone as well
as the subscriber line length very comfortably due to the help of the Level Metering
Function and the built-in tone generators.
8.10.2 Improvement of Transhybrid Balancing
The Level Metering Function can also be used for an improvement of transhybrid
balancing. This can be very useful after calculating the filter coefficients via QSICOS
software and getting a too low transhybrid loss because of too long (or too short)
subscriber lines. With the knowledge of the subscriber line impedance and the telephone
impedance an optimization of the transhybrid loss is possible.
For it a configuration like in figure 38 is used. The transhybrid filter is enabled with bit
TH=1 of configuration register 0.
The tone generator 1 is programmed for sending a test frequency in the range between
300 and 3400 Hz, e.g. 300 Hz. The via Level Metering Function measured level (dBm0)
minus the send level (dBm0), minus the value RLR (dB) and plus the value RLX (dB) is
equivalent to the negative transhybrid loss.
Transhybrid loss/dB = send level/dBm0 + RLR/dB + RLX/dB - measured level/dBm0
In order to get information about the transhybrid loss over the whole frequency band
measurements at some other frequencies are necessary. In appendix E is a list of some
frequencies and assigned tone generator coefficients.
If the transhybrid loss measurement results are to low, another coefficient set has to be
used for the respective channel. Either a transhybrid filter set of another channel can be
used or a new coefficient set can be written to the coefficient RAM.
For calculating a transhybrid filter coefficient set via QSICOS producing a high
transhybrid loss the value of the subscriber line impedance und the telephone
Semiconductor Group
79
Application Note: Level Metering
PSB 2132
PSB 2134
09.97