U4255BM-MFN Atmel, U4255BM-MFN Datasheet - Page 9

• 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: -

Integrated FM Band Filter
4519A–AUDR–03/02
Table 13. FM Band Filter Center Frequency Correction
For FM reception a band filter with variable bandwidth is integrated in front of the
demodulator to provide channel selectivity on the 2
be adjusted by Bit 0 to 3 (see Table 14) to be suitable for the present receiving condi-
tion. In WB mode, the bandwidth of the integrated filter is shifted to lower bandwidth
values, while the necessary channel selectivity is achieved by an external ceramic filter.
The center frequency of the integrated FM band filter can be adjusted by means of
Bit 14 to 17 (Bit 4 set to 1). The field strength after the integrated FM band filter that is
available at Pin 20 (Bit55 = 1) can be used for this purpose.
Table 14. Bandwidth of the Integrated FM Band Filter.
+ 0 kHz (default)
IF Correction
+ 12.50 kHz
+ 18.75 kHz
+ 25.00 kHz
+ 31.25 kHz
+ 37.50 kHz
+ 43.75 kHz
- 12.50 kHz
- 18.75 kHz
- 25.00 kHz
- 31.25 kHz
- 37.50 kHz
- 43.75 kHz
+ 6.25 kHz
IF Bandwidth
- 6.25 kHz
- 0 kHz
200 kHz
190 kHz
180 kHz
170 kHz
160 kHz
150 kHz
140 kHz
130 kHz
120 kHz
100 kHz
110 kHz
90 kHz
80 kHz
70 kHz
60 kHz
50 kHz
Bit 17
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
Bit 3
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
Bit 16
nd
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
Bit 2
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
IF. The bandwidth of this filter can
Bit 15
U4255BM-M
Bit 1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
Bit 14
Bit 0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
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