Selection of MOS tube

The MOS tube is a voltage-controlled device, while the triode is a current-controlled device. The following briefly introduces how to select a MOS tube in engineering applications.

1. Encapsulation

Package refers to the shape and size of the MOS tube.The size of the package is basically proportional to the current that can be passed, and the size of the board should also be considered when selecting, so it is appropriate.

2.Vgsth

For the NMOS tube, applying a certain voltage to the GS can turn on the MOS tube. The size of this voltage, in terms of specifications, is Vgsth.The Vgsth of many MOS tubes is below 3.3V, so it can be directly controlled by the IO of the microcontroller powered by 3.3V, but this parameter must be confirmed.

3.Rdson

This parameter represents the DC resistance of the D-S terminal when the MOS tube is turned on.In engineering design, it is hoped that this parameter is as small as possible. Of course, the best one is 0R. In this case, the MOS tube is a simple switch and has no influence on the voltage of other parts. Moreover, the smaller this parameter is, the lower the partial pressure of the MOS itself.less heat.

4. Pass Current

In engineering, after all, the mos tube should be regarded as a switch, and the current that this switch can pass is a very critical factor. In theory, the larger the current, the better, but this parameter is directly proportional to the price, which satisfies the circuit design.That's it.

5.Nmos or Pmos

The difference between the two is that the direction of the voltage that needs to be applied is different, which can be based on actual needs.

After confirming the above information, you can basically choose a suitable MOS.Many parameters are not the bigger the better, the more perfect the better. Basically, they are positively related to the price. Just confirm the specifications carefully.