U4255BM-MFNG3 Atmel, U4255BM-MFNG3 Datasheet - Page 15

• Manufacturer Part Number: U4255BM-MFNG3
• Description: IC RCVR AM/FM FRONT-END 44-SSOP
• Manufacturer: Atmel

Specifications of U4255BM-MFNG3

• 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: Lead free / RoHS Compliant
• Features: -
• Sensitivity: -
• Memory Size: -
• Data Rate - Maximum: -

Multipath Sensor
4519A–AUDR–03/02
Table 27. Output Voltage of Adjacent Channel Sensor for Different Receiving
The multipath sensor is active in FM mode only and measures the disturbance due to
multipath reception. The multipath sensor detects drops in the field strength after the
integrated band filter by calculating the difference between an averaged maximum field
strength and the current field strength. The maximum depth of these drops is repre-
sented by the voltage of the peak detector at Pin 40 (MULTIP). The level of this voltage
represents the degree of disturbance in the received signal.
Figure 9. Multipath Sensor
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 29), the MPX signal may be muted and this situation (MPINT) can be signal-
ized at Pin 21 (INT) according to Table 24. Muting of the MPX signal during multipath
disturbances can be activated be setting Bit 8.
Table 28. Multipath Noise Canceller
Adjacent Channel Disturbance
Conditions and Center Frequencies
Multipath Noise Canceller
above
below
no
Not active
Active
+
300 kHz
high
high
low
4k
Pin40
450 kHz
high
high
low
U4255BM-M
Bit 8
0
1
600 kHz
high
high
low
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