SLVAE69 July   2019 TPS568215 , TPS56C215

 

  1.   Expand Buck Converter Minimum Input Voltage with External VCC Bias
    1.     Trademarks
    2. 1 TPS56C215 Introduction
    3. 2 12 V / 5 V O-ring supply for DDR application
    4. 3 Schematic and Bench Results
      1. 3.1 Efficiency Comparison
      2. 3.2 Bench Waveforms
    5. 4 Conclusion
    6. 5 References

3.2 Bench Waveforms

Figure 6 through Figure 13 show TPS56C215 steady state, start up, shut down and ORing switch waveforms. It indicates that with external VREG5 power supply, TPS56C215 could support applications with input voltages as low as 4 V. 5 V and 12 V rails switches can be realized smoothly

Fig6. VIN=4V, 0A.pngFigure 6. Steady State, VIN= 4 V, IOUT= 0 A
Fig7. VIN=4V, 12A.pngFigure 7. Steady State, VIN= 4 V, IOUT= 12 A
Fig8.pngFigure 8. Start Up, VIN= 4 V, IOUT= 0 A
Fig9.pngFigure 9. Shut Down, VIN= 4 V, IOUT= 0 A
Fig10.pngFigure 10. Start Up, VIN= 4 V, IOUT= 2 A
Fig11.pngFigure 11. Shut Down, VIN= 4 V, IOUT= 2 A
Fig12.pngFigure 12. O-ring Switch, VIN 5 V to 12 V, IOUT= 2 A
Fig13.pngFigure 13. O-ring Switch, VIN 12 V to 5 V, IOUT= 2 A