SLVAF76 August   2021 TPS62901 , TPS62902 , TPS62902-Q1 , TPS62903 , TPS62903-Q1

 

  1.   Trademarks
  2. 1Applications With Limited Area
    1. 1.1 Best TPS62903 Configuration to Reduce Size
    2. 1.2 Design Example
  3. 2Applications With High Efficiency and Thermal Requirement
    1. 2.1 Conduction Losses in the MOSFET
    2. 2.2 Conduction Losses in the Inductor
    3. 2.3 Switching Losses in the MOSFET
    4. 2.4 Losses in the Input and Output Capacitors
    5. 2.5 Analysis and Recommendations
  4. 3Conclusion

2.2 Conduction Losses in the Inductor

The same as Section 2.1, the conduction losses in the inductor are caused by the resistive element of the inductor as the current flows through the inductor. The resistive element of the inductor is known as DCR of the inductor, typically provided in the data sheet, and it is generated by the windings that form the inductor. The conduction loss in the inductor can be estimated in the same way as for the FET, see Equation 3:

Equation 3. Conduction_Loss_Inductor=IOUT_rms2 × DCR

In this report, DCR loss estimation is good enough to understand the conduction losses. In addition to the losses caused by the resistive element of the inductor, there are core losses determined by the magnetic properties of the inductor as well as AC resistance of the inductor (ACR). The calculation of the core and ACR losses are too complex for the purpose of this application, so they are not described here.