There are many parameters of field effect tubes, including DC parameters, AC parameters and limit parameters, but the following main parameters should be paid attention to in general use:

1. IDSS - saturated drain-source current. Refers to the drain-source current when the grid voltage UGS=0 in junction or depletion type insulated grid Fets.

2, UP - clamping voltage. Refers to the gate voltage in junction or depletion type insulated grid field effect tube when the drain source is just cut off.

3. UT - Opening voltage. Refers to the grid voltage in the enhanced insulated grid field effect tube when the drain and source are just switched on.

4. gM - transconductance. Is the control ability of gate source voltage UGS to drain current ID, that is, the ratio of the change of drain current ID to the change of gate source voltage UGS. gM is an important parameter to measure the amplifying ability of Fets.

5. BUDS - Breakdown voltage of drain-source It refers to the maximum drain-source voltage that the field effect tube can withstand in normal operation when the gate source voltage UGS is constant. This is a limiting parameter, and the working voltage on the field effect tube must be less than BUDS.

6. PDSM -- maximum power dissipation. Is also a limiting parameter, refers to the maximum allowable drain-source power dissipation when the performance of the field effect tube remains unchanged. When used, the actual power consumption of the FET should be less than PDSM with a certain margin.

7. IDSM -- Maximum drain-source current. Is a limiting parameter, refers to the maximum current allowed between the drain and source when the field effect tube is working normally. The working current of the field effector should not exceed IDSM.