SLYY193B July   2020  – January 2023 LMQ61460-Q1 , TPS54319 , TPS62088 , TPS82671 , UCC12040 , UCC12050

 

  1.   At a glance
  2.   Authors
  3.   3
  4.   What is power density?
  5.   What limits power density?
  6.   What limits power density: switching losses
  7.   Key limiting factor No. 1: charge-related losses
  8.   Key limiting factor No. 2: reverse-recovery losses
  9.   Key limiting factor No. 3: turn-on and turn-off losses
  10.   What limits power density: thermal performance
  11.   How to break through power density barriers
  12.   Switching loss innovations
  13.   Package thermal innovations
  14.   Advanced circuit design innovations
  15.   Integration innovations
  16.   Conclusion
  17.   Additional resources
A key to design success is often to reduce the size of the power supply. Space is limited. There is constant pressure to do more with less. More broadly, the miniaturization of power supplies has and will continue to enable new markets and applications.

At a glance

This paper examines the limitations to increasing power density and provides technology examples that can help designers overcome these barriers.

1 What is power density?
Power density can be viewed several ways depending on the application, but the goal remains the same: Reducing solution size leads to improvements in power density.
2 What limits power density?
The primary factors limiting a designer’s ability to improve power density are converter power losses — including conduction, charge-related, reverse-recovery, and turn-on and turn-off losses — and the thermal performance of the system.
3
How to break through power density barriers
Designers must attack each limiting factor in parallel: reducing switch losses; improving package thermal performance; adopting innovative topologies and circuits; and embracing more passive integration.