6 Summary

The THVD8000 and THVD8010 are excellent devices when trying to communicate over a power line. Lower voltage systems (< ~30 V) with line to ground impedance’s of 375 Ω benefit from the standard approach outlined in both the THVD8000 and THVD8010 data sheets as well as the THVD8000 design guide. Higher-voltage systems with line to ground impedance’s of less than 375Ω can benefit from the implementations detailed in this application note. To integrate the THVD8000/THVD8010 into a higher voltage and/or lower impedance systems modifications to the standard approach must be made. By utilizing a line driver such as the THS6222 in addition to the THVD8000 and THVD8010 to transmit RS-485 data; lines with less than 375 Ω to ground can be used as a transmission medium. With the addition of a protection circuit with a robust high-voltage interface not only can lines with less than 375 Ω be driven, but the high voltage signal pathway is isolated away from the communication circuit allowing for communication over the powerlines of any voltage if the interface can block and or filter out the high voltage signal. The THVD8000 and THVD8010 devices are excellent parts for transmitting RS-485 data over power lines and with a few modifications can be expanded to fit in most power line communication-based applications.