SLVA478C October   2013  – November 2022 TPS62120 , TPS62122

 

  1.   Using the TPS62120 in an Inverting Buck-Boost Topology
  2.   Trademarks
  3. 1Inverting Buck-Boost Topology
    1. 1.1 Design Considerations
    2. 1.2 Concept
    3. 1.3 Output Current Calculations
    4. 1.4 VIN and VOUT Range
  4. 2Digital Pin Configurations
    1. 2.1 Enable Pin
    2. 2.2 SGND Pin
    3. 2.3 Power Good Pin
  5. 3Startup Behavior and Switching Node Consideration
  6. 4External Component Selection
    1. 4.1 Inductor Selection
    2. 4.2 Input Capacitor Selection
    3. 4.3 Selecting L and COUT for Stability
  7. 5Typical Performance and Waveforms
  8. 6Conclusion
  9. 7References
  10. 8Revision History

6 Conclusion

Even if the TPS62120 can be configured as an inverting buck-boost converter to generate a negative output voltage. But we don't recommend TPS62120 for inverting buck-boost applications. The detailed explanation is in section 1.1 Design Considerations. The inverting buck-boost topology changes some system characteristics, such as input voltage range and maximum output current. This application report explains the inverting buck-boost topology and how to select the external components with the changed system characteristics. Measured data from the example design are provided. This report also applies to the TPS62122.