This reference design is a wide input: 12-V/2-A output isolated flyback converter using LM5155. The switching frequency is 250 kHz and the peak efficiency of the system is 89.19% at 24-V input. The load regulation in the whole input range is within ±0.5%. Peak-to-peak ripple of the output is within 296-mV under load transient from 1 A to 2 A with a slew rate of 1 A/us.