SIZING steps and Interpreting Mosfet datasheet

Interpreting Maximum Power of a MOSFET from the datasheet

How to interpret Vgs(th) min/max in a MOSFET datasheet?

https://www.infineon.com/dgdl/Infineon-ApplicationNote_Linear_Mode_Operation_Safe_Operation_Diagram_MOSFETs-AN-v01_00-EN.pdf?fileId=db3a30433e30e4bf013e3646e9381200

what i understand :

clarify coniditons :

fet calculation :

1)Vgs min :

from zero thermal coeffcient , from gaph : Ids , Vgs , to prevent thermal runaway

2)Vgs max : from datasheet Vgss

3)Vds max : From Safe operating Area graph , before thermal instability line, and keep in mind power limit .

project calculation :

1) first model my load , to know its impedance , resistance 2) calculate Vds = Vbattery - Load Voltage drop , Vd = Vb , Vs = Vd-Vds

( stated in pdf that Vds depends on voltage drop of load )

3) controlling Vg so it can be variable or constant , connect it to ground so it becomes zero

4) calculate Id ,from Id , Vds graph at known Vgs

Does these steps are correct , fully understood or i miss something ?

i want to know in Ids ( Vds graph )

is linear region , when Vds before V pinch ? and this region correspond to Rds on limit in SOA graph ?

also does saturation region corresponds to package limited ?

if these are correct what does max power limit corresponds to in Ids Vds graph ?

• Where did you find schematic with load and supply on wrong sides Commented Feb 18, 2020 at 14:47
• @TonyStewartSunnyskyguyEE75 sorry i dont understand what do u mean Commented Feb 18, 2020 at 15:28
• Swap supply and load if you want correct polarity. Commented Feb 19, 2020 at 1:54
• infineon.com/dgdl/… Commented Feb 19, 2020 at 10:44
• @TonyStewartSunnyskyguyEE75 please read this , u will find they use it the same way like im using , also i have already tested and simulated it and works fine , actually im asking about sizing and doing calculations Commented Feb 19, 2020 at 10:45