In the design, MOS tubes are usually used to design the slow-start circuit. The MOS tube has the characteristics of low on-resistance Rds and simple drive, and a slow-start circuit can be formed by adding a small number of components around it. Typically, PMOS is used for the positive power supply and NMOS is used for the negative power supply.
D1 is a clamp diode to prevent excessive input voltage from damaging the post-stage circuit;
The role of R2 and C1 is to realize the anti-jitter delay function. In practical applications, R2 is generally selected to be 20K ohms, and C1 is selected to be about 4.7uF。