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With the development and innovation in power electronics technology, switch-mode power supply technology is also constantly evolving. Today, switching power supplies are widely used in almost all electronic devices thanks to their compact size, light weight, and high power output; they represent an essential power supply solution for the rapid development of the modern electronics industry. A switching power supply is used in contrast to a linear power supply. At its input end, it rectifies alternating current into direct current, and then, under the action of a high-frequency oscillation circuit, uses switching transistors to control the on and off of the current, thereby generating high-frequency pulse currents. With the help of an inductor (high-frequency transformer), a stable low-voltage DC voltage is output. Because the size of the transformer’s core is inversely proportional to the square of its operating frequency; the higher the frequency, the smaller the core. This allows for **reducing the transformer, thereby minimizing the weight and size of the power supply. And because it directly controls direct current, the power of this type of power supply is much higher than that of linear power supplies. This saves power, which is why it is favored by people. But it also has disadvantages: the circuit is messy, difficult to repair, and causes severe contamination of the circuit. The power supply has high noise, making it unsuitable for certain low-noise circuits. With the development and innovation in power electronics technology, switch-mode power supplies are now widely used in almost all electronic devices, thanks to their features of small size, light weight, and high efficiency, which underscores their importance. Based on the way switching components are connected in a circuit, switch-mode power supplies can generally be divided into three main categories: series switch-mode power supplies, parallel switch-mode power supplies, and transformer-based switch-mode power supplies. Among them, transformer-based switching power supplies can be further divided into various types such as push-pull, half-bridge, and full-bridge. Based on the phase of the transformer’s excitation voltage and output voltage, it can be further classified into various types such as forward flux, flyback, single-flux, and double-flux topologies. A typical power supply is usually a linear power supply, which refers to a power supply in which the control transistor operates in a linear regime. In switching power supplies, however, it’s different. The switching transistor (in switching power supplies, we generally refer to the control transistor as the switching transistor) operates in two states: on – when its resistance is very low ； Off – high resistance. A switching power supply is a relatively new type of power supply. It has advantages such as high power, light weight, the ability to step up and step down voltage, and high output power. However, because of the circuit operation in switching mode, the noise is relatively high. What is common to both conventional power supplies and switching power supplies is the use of a voltage regulation transistor, which operates based on certain reaction principles to stabilize the voltage. The difference lies in the fact that switching power supplies use switch transistors for regulation, while conventional power supplies typically utilize the linear amplification region of transistors for this purpose. In comparison, switching power supplies have low power consumption, a wide operating range for AC voltage, and good ripple characteristics of the output DC voltage; their drawback is switch pulse interference.