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

3 External Component Selection

The inductor and output capacitor must both be selected based on the requirements of the application and the stability criteria of the device, which are different from the traditional buck converter approach. A load transient test needs to be performed to evaluate stability. Figure 4-7 shows the results of such a test performed on the example circuit. The lack of ringing indicates stability.