TXC-02050CIPL ETC1 [List of Unclassifed Manufacturers], TXC-02050CIPL Datasheet - Page 22

• Manufacturer Part Number: TXC-02050CIPL
• Description: MRT Device 6-,8-,34-Mbit Line Interface TXC-0250C
• Manufacturer: ETC1 [List of Unclassifed Manufacturers]

Line Side Output Characteristics
The line side output of the MRT switches from “rail to rail” on both of its output leads, TPO and TNO. This pro-
vides the maximum voltage swing, and makes the output voltage depend on the +5 volt power supply input to
the chip. The external circuit design must therefore be done with care in order to assure meeting the amplitude
requirements.
Line Side Output Circuits
Figure 13 illustrates the output circuit required for operating the MRT device in a 34368 kbit/s application with-
out a socket. The transformer and resistors shown assure that the output waveform meets the ITU-T mask for
34368 kbit/s transmission and that the MRT device is operated within the current limits of the TTL24mA output
parameters. The 1:2 transformer should have a frequency response of 0.2 MHz < f < 80 MHz with an insertion
loss of 1dB, maximum (suitable devices include Coilcraft part no. WB-1040 and Pulse Engineering part no.
PE-65969).
Figure 14 shows a variation of the circuit in Figure 13. This circuit improves performance in applications when
a plastic device is mounted in a socket. The additional low-pass filter compensates for possible overshoot
caused by inductance created by the device/socket interface. The 1:2 transformer should have a frequency
response of 0.2 MHz < f < 80 MHz with an insertion loss of 1dB, maximum (suitable devices include Coilcraft
part no. WB-1040 and Pulse Engineering part no. PE-65969).
The peak voltage and current output requirements for 6312 and 8448 kbit/s operation are different from those
for 34368 kbit/s operation. Figure 15 illustrates the output circuit required for 6312 kbit/s and 8448 kbit/s opera-
tion. The 1:1 transformer should have a frequency response of 0.2 MHz < f < 80 MHz with an insertion loss of
1dB, maximum (suitable devices include Coilcraft part no. WB-1010 and Pulse Engineering part no.
PE-65966). The transformer, drivers and resistors assure that the output waveform meets the pulse mask
requirements for these rates and that the MRT device is operated within the current limits of the TTL24mA out-
put parameters.
Proprietary TranSwitch Corporation Information for use Solely by its Customers
Transmit
Output
Data
Figure 13. Line Side Output Circuit Outline - No Socket (34368 kbit/s)
Figure 14. Line Side Output Circuit Outline - Socket (34368 kbit/s)
Transmit
Output
Data
1 : 2
DATA SHEET
1 : 2
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100
100
150
150
18 pf
18 pf
75
75
34
33
TXC-02050C
34
33
Device
MRT
TXC-02050C
Device
MRT
TXC-02050C
TXC-02050C-MB
Ed. 1, May 2002
MRT