Performance Data and Typical Characteristic Curves
11
SLUUBV6 – August 2018
Copyright © 2018, Texas Instruments Incorporated
Using the UCC28780EVM-021, 45-W, 20-V High-Density Silicon (Si) Based,
Active-Clamp Flyback Converter/Evaluation Module
Figure 11. AAM Mode at Heavy Loads (CH1 = PWML, CH4
= Transformer Primary Winding Current, CH2 = Switch
Node Voltage, CH3 = PWMH)
Figure 12. ABM Mode at Medium Loads (CH1 = PWML,
CH4 = Transformer Primary Winding Current, CH2 =
Switch Node Voltage)
Figure 13. ABM Mode and SR (CH1 = PWML, CH4 =
Transformer Primary Winding Current, CH2 = Switch Node
Voltage, CH3 = SR Vgs)
Figure 14. Recovery after OPP with 3 Stages of Peak
Current (CH1 = PWML, CH4 = Transformer Primary
Winding Current, CH2 = Switch Node Voltage)
Figure 15. LPM Mode Operation (when a burst packet
contains 2 pulses and the interval between 2 packets is
around 40µs, and peak current starts to reduce. CH3 =
PWML, CH4 = Transformer primary winding current.)
Figure 16. SBP Mode Operation
(when a burst packet contains 2 pulses and the interval
between 2 packets is > 40 µs. CH3 = PWML, CH4 =
Transformer primary winding current.)