SLLA590 May   2022 THVD8000 , THVD8010

 

  1.   Abstract
  2.   Trademarks
  3. 1Introduction
  4. 2THVD80x0 Devices Theory of Operation and Limitations of Use
    1. 2.1 Overview and Similarities between Standard RS-485 Transceivers and THVD80xo Devices
    2. 2.2 Differences between Standard RS-485 Transceivers and THVD8000/8010
    3. 2.3 Standard Approach to Using THVD80xo Devices to Communicate over Power Lines
    4. 2.4 Drawbacks to Standard Approach with Higher Voltage Systems
  5. 3Integration of Line Driver with THVD80x0 Devices to Drive Low Impedance Loads
    1. 3.1 Overcoming Drive Strength Requirement with A Line Driver Amplifier
    2. 3.2 Modification to Typical System Signal Chain Path Through Integration of Line Driver
  6. 4High Voltage Interface and Communication Interface Power Supply
    1. 4.1 Line Driver Output and Input RX signal Protection Circuit
    2. 4.2 High-Voltage Interface
    3. 4.3 Receive Path Optional Bandpass
  7. 5System Level View and Relation to Higher Voltage Implementations
    1. 5.1 Powering the Powerline Communication System
    2. 5.2 System Overview with Selected Test Results
    3. 5.3 Changes to Design for Higher Voltage AC or DC Applications
  8. 6Summary
  9. 7References

5.1 Powering the Powerline Communication System

One remaining challenge is presented with this type of circuit implementation – how to power it. There are two different power supplies used in this application:

  1. The Line Driver and Protection Circuitry Source.
  2. The THVD8000/THVD8010 + MCU/Related Devices VCC. Since this system is directly attached to a power line – the power should be sourced from here.

The first option is an offline converter which will take a rectified signal (AC) and step it down to the line driver voltage. The line driver power supply voltage is going to be larger than what the MCU/THVD8000/8010 can handle so another SMPS must be added to provide power for these objects as well. An optional LDO can also be used to get a smoother power signal for the MCU/THVD8000/THVD8010 devices. Some good devices to look at are the UCC28880 Offline Converter for the first stage of the power tree and then have that feed into a TPS62177 to generate the low VCC voltage for the THVD8000/THVD8010 and the MCU. The UCC28880 EVM also comes with a rectifier that can be used for AC applications. Check these device datas heets for instructions on how to set your voltages.