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

1 Using the TPS62120 in an Inverting Buck-Boost Topology

The TPS62120 is a synchronous buck dc-to-dc converter designed for low-power applications. It features a wide operating input voltage range from 2 V to 15 V, up to 96% efficiency, and 75-mA output current. This device family is well-suited for many applications such as ultra low-power microprocessors, energy harvesting, and low-power RF applications. Even though this application note describes the TPS62120 in an inverting buck-boost topology for use in low current negative rails for operational amplifier biasing and other low-power applications. This document also applies to the TPS62122.

Note: The TPS62120 configured as an inverting buck-boost topology is risky. We highly recommend using TPS629203 family for inverting buck-boost applications.