SLVAF44 April   2021 TPS5432

 

  1.   Trademarks
  2. 1Introduction
  3. 2Load Release Characteristics of SoC Chipset
  4. 3Unexpected Protection Behavior During the Load Release of SoC Chipset
  5. 4Investigation on a Long-Term Reliability
  6. 5Design Approaches to Improve the Load Release Characteristics of SoC Chipset
  7. 6Conclusion
  8. 7References

6 Conclusion

This application report shows the load release characteristics of SoC chipset using in FHD TV application. For the severe overshoot voltage on PH node in TPS5432 application which is for 1.2 V SoC rail, it can be caused by an unexpected OVT (Overvoltage transient protection) and RCP (Reverse current protection) under TV SoC load release condition.

In addition, when applying repetitive overshoot voltages to devices, LSFET gets softly damaged after 84,000 times as the worst case. therefore, the excessive overshoot voltage can impact a long-term device reliability.

A feasible approach is to add a RC snubber on the switch node (PH) to reduce the peak voltage level. Furthermore, in case the loop bandwidth is extended up to 37 kHz, an unexpected OVT and RCP is not observed. In the application, optimizing compensation network to extend the loop bandwidth is recommended approach.