MOSFETs are not only electronic components, but also a bridge for communication between us and our customers.
When customers ask, "How is the quality of your power supplies? Are they prone to failure?", this is a question our switching power supply sales representatives are frequently asked. So how can we answer customers' questions from a professional perspective, so that customers can better recognize the professionalism of our sales staff and thus increase their trust in our company's switching power supplies?
So, among the many components in a switching power supply, which one plays a crucial role in its durability? One of the most common power supply components is the MOSFET (Metal-Oxide-Semiconductor Transistor).
Customers are most concerned about power supplies exploding immediately upon power-on or frequently failing in areas with unstable power grids. This is related to the voltage stress on the MOSFET. To address this issue, we leave a 30% margin in our MOSFET selection to absorb voltage spikes generated by transformer leakage inductance, preventing instantaneous overvoltage breakdown. This design significantly reduces the after-sales rate, especially in industrial scenarios with large power grid fluctuations. Regarding the issue of power supply overheating, we can choose MOSFETs with low on-resistance, resulting in less heat generation. Furthermore, we pay special attention to the thermal resistance of the MOSFET, and with this heat dissipation structure, the junction temperature is well controlled. For every 10-degree Celsius reduction in temperature, the lifespan of electronic components doubles, making the power supply more durable even in harsh environments.
Regarding power switch noise, if the customer's equipment is a precision instrument or has communication functions, power supply noise can interfere with the normal operation of the equipment. For similar EMI issues, the switching characteristics of the MOSFET are often related. If the switching speed is too slow, losses are high; if it's too fast, spikes and ringing are likely to occur. Therefore, in designing the driver, we specifically adjust the gate resistor to make the MOSFET's switching edge both steep and clean, minimizing high-frequency noise. If the customer's load changes drastically, causing large power supply voltage fluctuations or even whistling, then the dynamic response requirements for our power supply are very high. Our power supply not only needs a well-tuned control loop but also requires a MOSFET with a matching switching speed. Its input capacitance and gate charge are optimized to quickly respond to load changes without causing oscillations in the control loop.
As the core component of our switching power supply, the MOSFET plays a crucial role in the stability, reliability, and durability of the switching power supply. Therefore, in the initial design stage of the switching power supply, our engineers fully consider the power supply's performance and cost when selecting MOSFETs. Our engineers at Kaihui Power will provide customers with cost-effective switching power supplies from the design stage. If you have any new design proposals or questions regarding power supply, please feel free to contact us. We will sincerely discuss them with you.
