Whether the MOS tube is driven well or not can be seen from the waveform.

All of the above are common waveforms in MOS tube driving.

① The first two rows are both square waves. It can be seen that one of the rising edges is relatively flat, while the other is relatively steep.

Usually, MOS tubes are turned on slowly and off quickly. The normal waveform is relatively flat, and the rising edge is slower than the falling edge.

The second square wave is the opposite, its switching speed is faster and the tube oscillates slightly.

Solution: Increase the gate drive resistance appropriately

② The second row of triangle-like waveform has very slow rising and falling edges, which is usually caused by insufficient driving capability of the driver chip.

Solution: Replace the driver chip with one with stronger driving capability

③ The two types in the third row belong to high-frequency ringing. The MOS tube has serious oscillation phenomenon and works in the linear region for most of the time. The loss is large and it is easy to cause the tube to heat up and burn.

Solution: Redraw the board