This is the schematic of the TDA5051A Power Line Modem (PLM) stand-alone demo board. The reference oscillator is provided by an 8.0000 Mega Hertz crystal at pins 7 and 8 of the TDA5051A. The 8.0000 Mega Hertz reference oscillator yields a carrier frequency of 125 kilo Hertz. The carrier frequency is the reference oscillator of 8.0000 Mega Hertz divided by 64, or 125 kHz. The +5 VDC supply is provided from an external source at pin 1 of the PLM_IF connector. The DATAIN and DATAOUT I/Os are pin 4 and pin 6 respectively of the PLM_IF connector. The TXOUT and RXIN data signals are filtered and isolated from the AC power line by T1, the converter transformer and the filter circuit components. The vendor and part number for the converter transformer is a Murata 78250. All components in the power line interface circuitry should be UL approved for AC operation from 0 to 230 V and DC operation from 0 to 48 Volts.