The AMC1303 uses an on-off keying (OOK) modulation scheme to transmit the modulator output bitstream across the capacitive SiO2-based isolation barrier. The transmitter modulates the bitstream at TX IN in Figure 44 with an internally-generated, 480-MHz carrier across the isolation barrier to represent a digital zero and sends a no signal to represent the digital one. The receiver demodulates the signal after advanced signal conditioning and produces the output. The symmetrical design of each isolation channel improves the CMTI performance and reduces the radiated emissions caused by the high-frequency carrier. Figure 44 shows a block diagram of an isolation channel integrated in the AMC1303.
Figure 45 shows the concept of the on-off keying scheme.