Talking about the use of MOS tube

  • CMS
  • May 6, 2019
  • 166

1. Compared with the current-controlled triode, the MOS tube is voltage control, which can be understood as a change from analog to half-number. In the switch state, it is a number, in the amplified state, similar to a half-number;

2. Due to the current-controlled triode, there will be a common current path between be and ce, so there is no isolation; MOS tube can be considered as quasi-isolated state, no common current channel; but need to pay attention to MOS tube After breakdown

Form a public passage, the hazard at this time should be analyzed, and the design should be considered in advance;

3. On the switching speed, due to the no current decay process, the speed is also improved a lot with respect to the triode, generally 100KHz can be satisfied;

4. Due to the above characteristics, and the on-resistance Ron of the MOS transistor is already relatively small, the power consumption is obviously superior to the triode, so many occasions have begun to gradually replace the triode;

5.p-type mos tube, low level conduction, high level cutoff; n-type mos tube, high level conduction, low level cutoff; different types of MOS tubes are used in different occasions, but need to consider N type MOS There are many types of tubes to choose from, the price is low, and the P type is small, so it should be considered comprehensively when using it;

6. MOS tube heat dissipation, when selecting, not only to see the current through the satisfaction, you must consider the heat problem, especially in the case of high current, heat dissipation needs to be careful, because heat dissipation is a process of continuous deterioration, high temperature, resistance Large, high resistance, higher temperature, so heat dissipation requires special attention. Considering that the heat dissipation and installation process are closely related, it is best to use the thermal infrared to measure the product when it is actually working for a long time. In the limit state, there is a certain margin.

The above is a rough understanding of the MOS tube, please correct me.