3.5.2.2 Modulation Type

The ATA8510/15 provides two basic modulation types that can be selected by setting the FSCR.SFM register bit:

• FSCR.SFM = 0: ASK modulation
• FSCR.SFM = 1: FSK modulation

The ASK modulation is implemented as pure ON/OFF keying (OOK). The power amplifier is switched off at a logic 0 and switched on at a logic 1 of the modulation data signal. The transmitted carrier frequency corresponds to the FFREQ1L/M/H setting.

In FSK mode, the power amplifier is constantly on. The modulation data signal switches between two frequencies, corresponding to the FFREQ1L/M/H and FREQ2L/M/H settings.