U4255BM-MFN Atmel, U4255BM-MFN Datasheet - Page 13

• Manufacturer Part Number: U4255BM-MFN
• Description: IC RCVR AM/FM FRONT-END 44-SSOP
• Manufacturer: Atmel

Specifications of U4255BM-MFN

• Frequency: 70MHz ~ 160MHz
• Modulation Or Protocol: AM, FM
• Applications: AM/FM Radio Receiver
• Current - Receiving: 50mA
• Data Interface: PCB, Surface Mount
• Antenna Connector: PCB, Surface Mount
• Voltage - Supply: 7.5 V ~ 10 V
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-SSOP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Features: -
• Sensitivity: -
• Memory Size: -
• Data Rate - Maximum: -

Deviation Sensor
4519A–AUDR–03/02
Table 22. Search Stop Detector Measurement Time
Table 23. Search Stop Window
Table 24. Signals Available at Digital Output Pin 21
The deviation sensor is active in AM and FM/WB mode and measures the modulation of
the signal. It is implemented as a peak detector of the lowpass-filtered MPX signal (see
Figure 7). The output voltage at Pin 31 is proportional to the frequency deviation in
FM/WB or the modulation depth in AM respectively.
Figure 7. Deviation Sensor
Time Window for Stop Signal
Bit 88
0
0
1
1
63 3.1969 ms
1 3.1969 ms
Search Stop Window
.....
MPX
± 0.5 kHz
± 1.1 kHz
± 2.3 kHz
± 4.8 kHz
± 10 kHz
± 20 kHz
± 40 kHz
± 80 kHz
1 (FM/WB)
1 (FM/WB)
0 (AM)
0 (AM)
Bit 92
Bit 78
0
1
Bit 77
0
1
NOT (STOP AND NOT MPINT)
+
25k
Bit 87
4k
Bit 76
0
0
0
0
1
1
1
1
0
1
INT (Pin 21)
NOT MPINT
NOT STOP
1
Pin 31
Bit 75
U4255BM-M
0
1
Bit 86
0
0
1
1
0
0
1
1
Bit 74
0
1
Bit 85
Bit 73
0
1
0
1
0
1
0
1
1
1
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