TDA7200 Datasheet, PDF (27/49 Pages) Infineon Technologies AG – ASK/FSK Single Conversion Receiver

TDA7200
Applications
asymmetrical offset for the demodulation of long zeros the lower of the two FSK
frequencies should be chosen in the transmitter as the zero-symbol frequency.
In the following figure the shape of the above mentioned bandpass is shown.
gain (pin19)
v
v-3dB
3dB
0dB
DC
20dB/dec
f1
f2
-40dB/dec
f
f3
Figure 10
0.18mV/kHz
2mV/kHz
Frequency characteristic in case of FSK mode
The cutoff frequencies are calculated with the following formulas:
1
f₁
=
2π
R1× 330kΩ
R1+ 330kΩ
× C13
f₂ = v × f₁ = 11× f₁
f₃ = f_3dB
f₃ is the 3dB cutoff frequency of the data filter - see Section 3.2.
Example:
R1 = 100kΩ, C13 = 47nF
This leads tof₁ = 44Hz and f₂ = 485Hz
Data Sheet
27
V 1.0, 2007-05-02