Why both channels don't have the same RDSon

[shaiko]

I want to use a dual transistor IC in my design to save PCB space.
Take a look at this device:
https://www.vishay.com/docs/65733/siz710dt.pdf
Why don't both of the channels have the same RDSon ?

 

[keith1200rs]

Why don't both of the channels have the same RDSon ?

Because the two transistors are different sizes. See the input capacitance.

Keith

 

[shaiko]

Are there any symetrical MOSFETs with very low RDSon ?

 

[keith1200rs]

Are you actually looking for a dual NMOS where one is driven as a source follower? It would help to know more about your application - an NMOS/PMOS push-pull would be more common.

Keith