SLVAFU9 January   2025 TPS62840 , TPS62843

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Inverting Buck-Boost Topology
    1. 1.1 Concept
    2. 1.2 Output Current Calculations
    3. 1.3 VIN and VOUT Range
  5. 2Design Considerations
    1. 2.1 Additional Input Capacitor
    2. 2.2 Digital Input Pin Configurations
    3. 2.3 Startup Behavior and Switching Node Consideration
  6. 3External Component Selection
    1. 3.1 Inductor Selection
    2. 3.2 Capacitor Selection
  7. 4Typical Performance
  8. 5Summary
  9. 6References

5 Summary

The TPS62840 buck dc-to-dc converter can be configured as an inverting buck-boost converter to generate a negative output voltage. 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 proper values of external components with the changed system characteristics. TPS62840 also gives design guidelines and precautions to make sure the robust operation of the converter. Measured data from the example design are provided. This application report also applies to any of the devices in the TPS6284x family.