The reason for severe heating of field-effect transistors

1. The problem with circuit design is to make MOS transistors operate in a linear state rather than in a switching state. This is also one of the reasons for the heating of MOS transistors. If N-MOS is used as a switch, the G-level voltage needs to be several volts higher than the power supply in order to fully conduct, while P-MOS is the opposite. The failure to fully open and excessive voltage drop result in high power consumption, high equivalent DC impedance, and increased voltage drop. Therefore, U * I also increases, and the loss means heat generation. This is the most taboo mistake in designing circuits;

2. The high frequency is mainly due to the excessive pursuit of volume, which leads to an increase in frequency and an increase in losses on the MOS transistor, resulting in increased heat generation;

3. Not having sufficient heat dissipation design, the current is too high, and the nominal current value of the MOS transistor generally requires good heat dissipation to achieve. So if the ID is less than the maximum current, it may also cause severe heating and require sufficient auxiliary heat sinks;

4. The selection of MOS transistor is incorrect, the power judgment is incorrect, and the internal resistance of MOS transistor is not fully considered, resulting in an increase in switch impedance.