28
4883B–AUDR–01/06
ATR4255P
8. Diagrams
The following data was measured with the application board (Figure 8-9 on page 32).
In the measurement setup, a 50Ω generator is terminated by 50Ω and connected to the antenna
input by a 50Ω series resistor to achieve 75Ω termination at the antenna input. The generator
level specified is the output voltage of this 50Ω generator at 50Ω load. If the application board is
replaced by a 75Ω resistor, the voltage at this resistor is 6 dB below the specified voltage level of
the 50Ω generator.
Figure 8-1. FM Demodulator
Note: Integrated bandfilter BW setting: 120 kHz, bits 0 to 2 = 0, bit 3 = 1;
1 kHz modulation frequency; 50 µs de-emphasis (THD).
Figure 8-2. Multipath Sensor
Note: AM modulation frequency 20 kHz; generator level 40 dBµV.
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
0 10203040 5060708090100
Frequency Deviation (kHz)
MPX Output Voltage (Vrms)
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
THD
%
MPX
THD
+85˚C
-40˚C
+85˚C
-40˚C
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
020406080100
AM Modulation Depth (%)
Sensor Output Voltage (V)
-40˚C
+25˚C
+85˚C
