W742S819 Datasheet, PDF (10/11 Pages) Winbond – 4-BIT TELEPHONE CONTROLLER

W742S819
9. APPLICATIONS INFORMATION
9.1 Operating Voltage
The chip can be operated from 2.4V-5.5V. If users have much consideration for low power operation,
lower voltage supply system can be a better choice.
9.2 Drive Abilities of OP-AMPs
The OP-AMPS have 2 types according to their drive abilities. OP2 and OP3 have weaker drive
abilities than which OP1 does, so OP2 and OP3 are provided for driving input port like RC.n.
9.3 FSK Signal Detection and FSK Demodulation
9.3.1 FSK Signal Detection
Figure 10-1 is a typical application circuit for FSK signal detection and FSK demodulation. For purpose
of signal detection, user should enable both OP1 and OP2, output low to control and sense the signal
by RC.n.
9.3.2 FSK demodulation
For purpose of FSK demodulation, user should enable both OP1 and OP2, output high to control, and
sense the FSK signal by RC.n. and demodulate FSK by software.
Figure 9-1 Application Circuit for FSK Signal Detection and FSK demodulation
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