CXA1994 SONY [Sony Corporation], CXA1994 Datasheet - Page 6

• Manufacturer Part Number: CXA1994
• Description: M-ary FSK Demodulating Comparator
• Manufacturer: SONY [Sony Corporation]

Description of Operation
M-ary (M = 2- or 4-level) FSK emodulation system
Polarity discrimination output and MSB comparator output are used to demodulate the 4-level waveform shown
below.
4-level FSK demodulating waveform
Polarity discrimination output
MSB comparator output
The 4-level FSK demodulating data is divided into a polarity discrimination output and a MSB comparator
output shown above. Here, the polarity discrimination output corresponds to a conventional NRZ comparator
output. The MSB comparator output is made comparing to the optional level setting between MSB and LSB
levels as reference.
For the 2-level FSK demodulation, it corresponds to a conventional NRZ comparator output.
Take care that the polarity of NRZ output is inverted in CXA1484A.
POS
NEG
1.6kHz
4.8kHz
+4.8kHz
+1.6kHz
–1.6kHz
–4.8kHz
01
1
0
00
0
0
– 6 –
10
0
1
11
1
1
01
1
0
10
0
1
00
0
0
CXA1994AM/BM