High-Efficiency Resonant Flyback Controller

PANJIT’s resonant flyback controller integrates a high-side 650 V/4 A 1.2 Ω MOSFET in the package. Unlike the passive snubber circuit (lossy snubber) used in traditional flyback systems, this flyback controller utilizes an active snubber circuit (lossless snubber) to make more effective use of the extra energy (leakage inductance and stray components) in the flyback system (energy recycling).

Benefiting from the unique control strategy, both of the systems power switches (high-side MOSFET and low-side MOSFET) are almost always zero voltage switching (ZVS). Therefore, the switching loss of the power switches can be minimized and the efficiency can be optimized. Moreover, by using SJMOS power devices and the common materials of the traditional flyback system, a high-efficiency and high-power-density flyback power system can be easily realized. This resonant flyback controller can also be used in conjunction with GaN or SiC to meet higher-frequency power system design requirements.