SLVA514C July   2014  – November 2022 TPS62125

 

  1.   Using the TPS62125 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 Enable Hysteresis Pin
    3. 2.3 Power Good Pin
    4. 2.4 Discharging the Output Voltage
  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 TPS62125 in an Inverting Buck-Boost Topology

The TPS62125 3-V to 17-V, 300-mA Step-Down Converter With Adjustable Enable Threshold and Hysteresis data sheet is a DCS-Control™ topology synchronous buck dc-to-dc converter designed for low-power applications. It features a wide operating input voltage range from 3 V to 17 V, 300-mA output current, and adjustable output voltage of 1.2 V to 10 V. This device is well-suited for applications such as ultra low-power microprocessors, energy harvesting, and low-power RF applications. Even though the TPS62125 can be configured in an inverting buck-boost topology, where the output voltage is inverted or negative with respect to ground. This application note describes the TPS62125 in an inverting buck-boost topology for use in low current negative rails for operational amplifier or optical module biasing and other low-power applications.

Note: The TPS62125 configured as an inverting buck-boost topology is risky. We highly recommend using TPS629203 family for inverting buck-boost applications.