Datasheet

ST7538Q Functional description
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5 Functional description
5.1 Carrier frequencies
ST7538Q is a multi frequency device: eight programmable Carrier Frequencies are available
(see Ta ble 5).
Only one Carrier could be used a time. The communication channel could be varied during
the normal working Mode to realize a multifrequency communication.
Selecting the desired frequency in the Control Register the Transmission and Reception
filters are accordingly tuned.
5.2 Baud rates
ST7538Q is a multi Baud rate device: four Baud Rate are available (See Table 6.).
Table 5. ST7538Q Channels List
FCarrier F (KHz)
F0 60
F1 66
F2 72
F3 76
F4 82.05
F5 86
F6 110
F7
(1)
132.5
Table 6. ST7538Q mark and space tones frequency distance vs baud rate and deviation
Baud Rate [Baud]
∆F
(1)
(Hz)
1. Frequency deviation.
Deviation
(2)
2. Deviation = ∆F / (Baud Rate)
600 600
1
(3)
3. Deviation 0.5 Not Allowed
1200 600
1200
0.5
1
2400
(4)
4. Default value
1200
(4)
2400
0.5
1
4800 2400
4800
0.5
1