SLLA573 May   2022 THVD8000

 

  1.   Trademarks
  2. 1Introduction
  3. 2Tests and Setup
    1. 2.1 Test 1: 4-Node Star Network Test
    2. 2.2 Test 2: 4-Node Terminated Star Network Test
    3. 2.3 Test 3: 4-Node Loaded and Terminated Star Network Test
    4. 2.4 Test 4: 4-Node Loaded and Terminated Star Network Test with Line Driver
  4. 3Summary

3 Summary

In summary, several tests are presented for the star network systems. Specifically, two techniques are discussed in detail. First, terminating every stub of non-daisy chain network can greatly improve signal integrity, which will widely expand the use cases of RS-485 systems. Second, high speed amplifiers can be used as line drivers for PLC applications to drive low-impedance systems. Other than the heavy load system discussed here, outlet AC power line usually has low impedance, where this technology can be applied too. The measurement data presented in this application note hopefully will give the designers more ideas about special RS-485 and PLC systems.