SLLA646 August   2024 ISO6520 , ISO6521

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
    1. 1.1 Where are Digital Isolators Commonly Used?
    2. 1.2 What is Functional Isolation?
    3. 1.3 Key Benefits of Functional Isolation
  5. 2Application Use Cases
    1. 2.1 Telecom Power Supplies
      1. 2.1.1 48V Isolated DC-DC
      2. 2.1.2 48V Non-Isolated DC-DC
    2. 2.2 Server Power Supply
      1. 2.2.1 Totem-Pole Power Factor Correction Stage
      2. 2.2.2 Half-Bridge LLC Stage
    3. 2.3 AC - DC Power Supply in Pluggable Wall-Chargers
      1. 2.3.1 Introduction
      2. 2.3.2 Topology Details
      3. 2.3.3 Using ISO65xx for Reliable PWM Signaling
    4. 2.4 Semiconductor Test and Measurement
  6. 3Conclusion
  7. 4References

2.3.3 Using ISO65xx for Reliable PWM Signaling

A functional isolator like ISO65xx can be used between the controller and high-side FET for reliable system operation.

The ISO65xx family of devices are an excellent fit for this application. Functional isolators like ISO65xx can be used between ACF controller and the Power FET to block a high common mode and faithfully communicate PWM signal across the barrier under high-voltage transient conditions.

Functional Isolation working voltage (VIOWM) needed for this application can be typically 400V, depending on the voltage input from AC Mains. Momentary high voltage transients may get induced in the system due to variants in the AC mains input or line surges, which the isolator needs to withstand.

Common mode transient immunity (CMTI) robustness is also essential to account for high-voltage switching activity from power FETs, as high as 100kV/μs.