256-KBPS LINE DRIVER (V.35, RS-530, OR X.21)
NOTE
In multipoint applications, do not use the
2.2.2MODULATION TIMING
This circuit supplies the transmit clock to the encoder. Three clock sources are available on the XMT CLK jumper (J3):
•
•
•
There is also an ASY (asynchronous) setting, but this has no function and should not be selected.
2.2.3SIGNAL LEVELS
Two options are available for the transmit and receive signal levels: 0 and
2.2.4RECEIVER
The receiver comprises several circuits, as shown in the block diagram (see Figure
•The RECEIVE FILTER, which removes all the
•The EQUALIZER, which comprises several equalizers activated according to data rate.
•The digital Automatic Gain Control (AGC), which automatically compensates for the attenuation of the line.
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