CPC5604
Snoop Mode Distortion
signals coupled through the snoop circuit are either
20Hz ring signals or FSK CID signals. A graph of
THD+N for the snoop mode is shown in Figure 9B.
Figure 9A can be used for the snoop mode distortion
test. Snoop mode operation requires that the DAA be in
—
the on-hook state and the CID pin asserted (driven
Low). Distortion in the snoop mode is not critical since
Figure 9A Snoop Mode Distortion Setup
RX+
IN1
Audio
TIP
Precision
AP1
100K
V
System One
Analyzer
RX
Audio
Precision
Generator
IN2
600
LITELINKTM DAA Circuit
V
RX-
T/R
-13dbm
1800Hz
RING
CID
Figure 9B Snoop Mode THD + N
dBm
500
1K
1.5K
2K
2.5K
3K
3.5K
4K
XXX
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