PEB3086 Infineon Technologies, PEB3086 Datasheet - Page 61

• Manufacturer Part Number: PEB3086
• Description: ISDN Subscriber Access Controller
• Manufacturer: Infineon Technologies

Protection Circuit for Transmitter
Figure 29
Figure 29
The external resistors (5 ... 10 W ) are required in order to adjust the output voltage to the
pulse mask on the one hand and in order to meet the output impedance of minimum 20 W
(transmission of a binary zero according to ITU-T I.430) on the other hand.
Two mutually reversed diode paths protect the device against positive or negative
overvoltages on both lines.
An ideal protection circuit should limit the voltage at the SX pins from – 0.4 V to V
+ 0.4 V. With the circuit In
V
becoming active if the 96 kHz test signal is applied while no supply voltage is present.
Data Sheet
DD
+ 0.7 V. The resulting forward voltage of 1.4 V will prevent the protection circuit from
illustrates the secondary protection circuit recommended for the transmitter.
SX1
SX2
External Circuitry for Transmitter
Figure 29
5 ... 10
5 ...10
Ohm
Ohm
the pin voltage range is increased from – 1.4 V to
61
Vdd
Description of Functional Blocks
1:1
21150_23
S Bus
PEB 3086
2003-01-30
ISAC-SX
DD