ATR4258 Datasheet, PDF (19/38 Pages) ATMEL Corporation – AM/FM RECEIVER IC

ATR4258
A Multipath Noise Canceller (MNC) is implemented to reduce disturbance of the
received signal in multipath reception conditions. If the difference between the momen-
tary and the averaged field strength falls below a threshold adjustable by bit 81 to 84
(see Table 32), the MPX signal may be muted and this situation (MPINT) can be signal-
ized at pin 21 (INT) according to Table 29 on page 17. Muting of the MPX signal during
multipath disturbances can be activated be setting bit 8.
Table 31. Multipath Noise Canceller
Multipath Noise Canceller
Active
Not active
Bit 8
0
1
Table 32. Sensitivity of the MNC
Sensitivity MNC (Threshold)
Off
Low
...
(-33 dB)
...
Normal (-14 dB)
...
High (-9 dB)
Note: Valid in FM or WB mode (bit 92 = 1)
Bit 84
0
0
...
0
...
0
...
1
Bit 83
0
0
...
0
...
1
...
1
The Multipath interrupt can also be switched on/off by bit 4.
Bit 82
0
0
...
1
...
1
...
1
Bit 81
0
1
...
1
...
1
...
1
Table 33. Multipath Interrupt (MPINT)
MPINT (Pin 21)
Off
On (MPINT active)
Bit 4
0
1
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