SLUAAP2 March   2023 LMG2610 , UCC28782

 

  1.   Abstract
  2.   Trademarks
  3. 1Introduction
    1. 1.1 Design Requirement 1: Managing Thermals Induced by Power Losses
    2. 1.2 Design Requirement 2: Reducing Energy Storage Requirement by Switching at High Frequency
  4. 2A Brief Introduction to GaN's Value
  5. 3The Active Clamp Flyback
    1. 3.1 Power Loss Saving 1: Zero-Clamp Loss
    2. 3.2 Power Loss Saving 2: Zero-Voltage-Switching
  6. 4The Value of GaN in Active Clamp Flyback
  7. 5Leveraging Integrated GaN to Simplify ACF Stage
  8. 6Physical Design Implementations Using LMG2610 Integrated Half-Bridge and UCC28782 ACF Controller
    1. 6.1 UCC28782EVM-030
    2. 6.2 PMP23146
  9. 7Leverage Design Tools for ACF
  10. 8Summary
  11. 9References

3 The Active Clamp Flyback

One of these properties of GaN can prove to be extremely valuable in one of the most efficient power converter topologies that addresses thermal and energy storage challenges: the Active-Clamp Flyback (ACF).

GUID-20230223-SS0I-G55J-NHQ0-XXBBDK1LJ2LV-low.svg Figure 3-1 Active-Clamp Flyback Power Stage

Compared to the traditional flyback, ACF greatly saves on power loss by:

  1. Eliminating losses in the traditional snubber clamp with zero-clamp-loss
  2. Reducing switching losses with Zero-Voltage-Switching (ZVS)
Both of these mechanisms are carried out by the configuration of the switching devices, magnetizing inductance, clamp capacitors, and parasitic elements, such as leakage inductance and device capacitance. The fundamental operation of these power loss-saving mechanisms is explained in more detail in Section 3.1 and Section 3.2.