U4255BM-M Datasheet, PDF (25/32 Pages) ATMEL Corporation – AM / FM RECEIVER IC

Diagrams
U4255BM-M
The following data was measured with the application board (see Figure 20).
In the measurement setup, a 50-W generator is terminated by 50 W and connected to
the antenna input by a 50-W series resistor to achieve 75-W termination at the antenna
input. The generator level specified is the output voltage of this 50-W generator at 50 W
load. If the application board is replaced by a 75-W resistor, the voltage at this resistor is
6 dB below the specified voltage level of the 50 W generator.
Figure 12. FM Demodulator
Integrated bandfilter BW setting: 120 kHz, Bits 0 to 2 = 0, Bit 3 = 1;
1 kHz modulation frequency; 50 ms de-emphasis (THD)
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
0
1
MPX
0.9
0.8
+85°C
0.7
0.6
-40°C
0.5
THD
0.4
0.3
-40°C
0.2
+85°C
0.1
10 20 30 40
50 60
70 80
0
90 100
Frequency deviation ( kHz )
Figure 13. Multipath Sensor
AM modulation frequency 20 kHz; generator level 40 dBmV
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
0
+85°C
-40°C
+25°C
20
40
60
80
100
AM Modulation Depth (%)
25
4519C–AUDR–07/02