JAJSJ67E may 2020 – july 2023 UCC28782
PRODUCTION DATA
There are two resonant approaches for an active clamp flyback (ACF) converter, primary resonance and secondary resonance, which affect the design guidance on the clamp capacitor (CCLAMP). Referring to Figure 9-1, if CO1 serves as the main energy-storage capacitor at the output with large capacitance and CO2 is a smaller high-frequency decoupling capacitor, leakage inductance of transformer (LK) mainly resonates with CCLAMP during the demagnetization time of LM. This configuration is called the primary-resonance ACF converter. On the other hand, if CO2 serves as the main energy-storage capacitor at the output with larger capacitance and CO1 is much smaller than the equivalent capacitance of CCLAMP reflected to the secondary side (CCLAMP*NPS2), LK mainly resonates with CO1. This configuration is called the secondary-resonance ACF converter.