MOS tube working status problem after turning on

bigbat

MOS tube working status problem after turning on [Copy link]

After MOS is turned on, is the resistance of Rds not affected by the voltage of Vds? That is to say, even when Vds=0V, the resistance of Rds and the Vds voltage during operation do not change much.

maychang

"That is to say, even when Vds=0V, the resistance of Rds does not change much when the Vds voltage during operation is the same."

Yes.

maychang

This can be clearly seen from the MOS tube output characteristic curve family.

PowerAnts

When VGS is constant, Rdson is affected by drain current, drain-source voltage, and temperature.

PowerAnts

Constant temperature conditions

VDS<VGS-VTH, variable resistance area, the slope remains unchanged and is considered constant resistance

VDS is near VGS-VTH, slows down, and the resistance increases with VDS

VDS>VGS-VTH, saturation region, constant current characteristics

led2015

When choosing MOS, many components from the same batch may have different performances, which can sometimes have a significant impact.

bigbat

PowerAnts published on 2022-3-25 19:43 Constant temperature condition VDS

Thank you, I finally understand this picture, that is to say, when the voltage of Vgs is below 8V and above Vgson, the Rdson of this tube is basically unchanged below 1V, but it is hard to say when Vds is between 1V and 10V. That is to say, the working start voltage of this tube is Vgs=10V, which is normal in the script.

Thanks again brother.