SLYT816 October   2021 TPS548B27 , TPS548B28

 

  1. 1 Introduction
  2. 2 Design considerations
  3. 3 Layout comparison
  4. 4 Thermal comparison
  5. 5 Efficiency comparison
  6. 6 Load transient comparison
  7. 7 Switch-node ringing comparison
  8. 8 Conclusion
  9. 9 Additional Resources
  10. 10Important Notice

5 Efficiency comparison

Table 5-1 shows the efficiency and power-dissipation comparisons between the two packages. A 3.3-V bias was applied to the VCC pin of each device in order to eliminate any losses from the internal linear regulator, which provides power to the IC. Linear regulator losses may differ from lot-to-lot process variations; you can remove them by applying the external 3.3-V bias voltage and obtaining the closest efficiency comparison. The efficiency and power-dissipation results from each package are very similar, but the HotRod package design had 50 mW less power dissipated, or 0.2% higher efficiency, at only 15 A, which is negligible. The Enhanced HotRod QFN package offered no improvement, with the slightest degradation of efficiency compared to the HotRod package.

Table 5-1 Efficiency comparison: 12-V input, 1-V output
Package IOUT (A) Efficiency Dissipation (W)
Enhanced HotRod QFN package 5.0 90.1% 0.55
10.0 89.6% 1.16
15.0 87.2% 2.21
20.0 84.6% 3.65
HotRod package 5.0 90.1% 0.55
10.0 89.6% 1.16
15.0 87.4% 2.16
20.0 84.6% 3.65