For testing, the soft-start circuit to the converter was set up with C SS = 0.1 µF, R SS = 100 kΩ, and R E = 1.18 kΩ. Figure 4 shows the soft-start waveform with these circuit parameters.

A simple circuit can implement a smooth soft start for an isolated converter in a system using the LM5025 active-clamp, voltage-mode PWM controller. Figure 2 shows the concept of this secondary ...