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

5.3 Capacitor and Choke Isolation

If the system uses capacitive based isolation, then it can be required for longer daisy chain cable lengths or highly noisy applications to use an additional common-mode choke filter in series with the capacitors. For these applications, it is recommended use an automotive grade 100 μH common-mode filter minimum for proper operation. To achieve the best performance in noisy environments, use dual common-mode filters (100 μH and 470 μH). For single common-mode filter applications, the TDK 51 μH 2.8kΩ choke (ACT45B-510-2P-TL003) is recommended. For dual common-mode filter applications, the TDK 100 μH 5.8 kΩ choke (ACT45B-101-2P-TL003) and Wurth 470 μH 2.2 kΩ (744242471) are recommended. Note that the common mode impedance specification is most critical to suppressing the higher noise sources. The same principle can be applied when determining choice of a ferrite bead.

GUID-05E7FBC6-36EA-4EFC-941F-7FBA9A1DB8C9-low.gif Figure 5-4 Capacitor and Choke Across PCBs