SLVAEP4 October   2023 BQ79600-Q1 , BQ79612-Q1 , BQ79614-Q1 , BQ79616 , BQ79616-Q1 , BQ79652-Q1 , BQ79654-Q1 , BQ79656-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1 Introduction
  5. 2 Receiver Topology and Common Mode Voltages
  6. 3 Signal Integrity Requirements
    1. 3.1 Receiver Timing Requirements
    2. 3.2 Receiver Threshold Requirements
  7. 4 Debug Fault Registers
  8. 5 Isolation Types
    1. 5.1 Transformer Isolation
    2. 5.2 Capacitor Only Isolation
    3. 5.3 Capacitor and Choke Isolation
  9. 6 Mixed Isolation Circuits using bq79600-Q1
  10. 7 Ring Architecture
  11. 8 Noise Immunity and Emissions
  12. 9 Daisy Chain Cable Selection
  13. 10References

9 Daisy Chain Cable Selection

Typically daisy chain testing is done with minimally short, symmetrical, matching impedance on-board pcb traces between devices or a 1 - 1.7m long twisted pair cabling between two separate pcbs or evaluation modules. However, depending on proper layout, isolation, and delay between commands - the communication protocol can support cabling up to 20-40m if needed but this would not be recommended for most robust solutions. The cabling material, twisting, and connectors can play a role in communication robustness but we do not provide strict requirements for these factors due to the flexibility provided to many different system architectures. However, testing has been completed with basic copper twisted pair wiring (no shielding) for many of our temperature and EMC testing. Although it may be best to use PP material rather than PVC material which changes the dielectric constant of the cable over time and temperature and thus has an impact on the transferred signals as opposed to more expensive, but better PP material. Typically for best practices is to support at least 1-2 twists per cable inch and start the twisting very close to the connectors. This will help reduce external effects of EMI interference.