How to select FET (02)

How to select FET (02)

2： Affirm the additional DC power of FET s

The additional DC power should be the maximum DC power that the load can accept under all conditions. Similar to the voltage condition, ensure that the selected MOS transistor can accept an additional DC current, even during sporadic spikes of DC current. The two contemplative DC conditions are sequential and pulse spikes. Under the continuous conduction mode, the MOS transistor is in steady state, and at this time, direct current gradually passes through the components. Pulse spike refers to a small amount of surge (or peak current) flowing through the machine. Once the maximum direct current in the department's environment is confirmed, it is only necessary to indirectly choose the components that can accept a certain maximum direct current.

After selecting additional DC power, it is also necessary to plan for conduction consumption. In practical situations, MOS s are not practical components, as there will be kinetic energy consumption during the heat conduction process, which is called conduction consumption. When the MOS transistor is "conducting", it is like a variable resistor, determined by the RDS (ON) of the component and significantly changes with the measurement. The power consumption of the components can be determined by Iload2 × RDS (ON) plans to adjust the power loss accordingly as the return resistance changes with the measurement. The higher the voltage VGS applied to the MOS transistor, the smaller the RDS (ON); On the contrary, the RDS (ON) will be higher. Note that the RDS (ON) resistance will slightly decrease with direct current. For various electrical families of RDS (ON) resistors

The changes in gas parameters can be found in the skill material list required by the builder FET