psf2115 ETC-unknow, psf2115 Datasheet - Page 86

• Manufacturer Part Number: psf2115
• Description: Isdn Adapter Circuit Ipac
• Manufacturer: ETC-unknow

PSB 2115
PSF 2115
Functional Description
Protection Circuit for Receivers
Figure 28 illustrates the external circuitry used in combination with a symmetrical
receiver. Protection of symmetrical receivers is rather comfortable.
Note: Capacitors are optional for noise reduction (up to 47 pF)
Figure 28
External Circuitry for Symmetrical Receivers
Between each receive line and the transformer a 10 k
resistor is used. This value is
split into two resistors: one between transformer and protection diodes for current limiting
during the 96 kHz test, and the second one between input pin and protection diodes to
limit the maximum input current ot the chip.
With symmetrical receivers no difficulties regarding LCL measurements are observed;
compensation networks thus are obsolete.
In order to comply to the physical requirements of CCITT recommendation I.430 and
considering the national requirements concerning overvoltage protection and
electromagnetic compability (EMC), the IPAC needs additional circuitry.
Semiconductor Group
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11.97