With the system fully explained it is time to look at how all these parts mesh together as well as look at some test data from a couple different implementations of these designs. Figure 5-1, Figure 5-2, Figure 5-3, and Figure 5-4 show the schematics of the THVD8000 (TX/RX), line driver interface, protection/filtering/high voltage interface, and the power tree respectively.

Figure 5-1 THVD8000 Schematic

Figure 5-2 THS6222 Schematic

Figure 5-3 Protection/Bandpass/HV Interface Schematic

Figure 5-4 Power Tree Schematic

This application uses a data rate of 2KHz, 110VAC line, modulation frequency of 125 KHz, a 16 V power supply for the THS6222 (±8 V), and a 3.3 V power supply for MCU and THVD8000. Test results are shown in Figure 5-5 through Figure 5-9 where TX and RX are the input/output of the THVD8000 respectively.

Figure 5-5 THVD8000 RX and TX signals; THS6222 Transmitting Signals

Figure 5-6 THVD8000 RX and TX signals; THS6222 Transmitting Signals - Zoomed Out

Figure 5-7 TX/RX data Overlaid on VAC Signal

Figure 5-8 TX/RX data Overlaid on VAC Signal Zoomed In

Figure 5-9 THVD8000 RX Signal on "A" Pin