Drain Current of Depletion Type MOSFET in two different regions

[ams_ei]

Hi,

I have a few doubts about depletion type MOSFET:


1. The schematic symbol of Depletion type MOSFET and Deletion-Enhancement type MOSFET are the same. Therefore, if any one of them is used in a circuit schematic, how can we distinguish them?


2. For Enhancement type MOSFET, the drain current in two different regions are:


Triode region:




Saturation Region:





What are the drain current equations for a Depletion type MOSFET in saturation region and triode region?


Would you be kind to clarify me the above two doubts?

Thank you.

 

[FvM]

1. Don't agree. There are different schematic symbols in use (broken versus continuous channel line). But some tools are using the depletion mode symbol for all MOSFETs (e.g. Cadence).

2. Both MOSFETs types only differ by Vth. In so far the same basic equations apply-

 

[ams_ei]

1. Don't agree. There are different schematic symbols in use (broken versus continuous channel line). But some tools are using the depletion mode symbol for all MOSFETs (e.g. Cadence).

2. Both MOSFETs types only differ by Vth. In so far the same basic equations apply-

Hi,

Thanks for your reply.

In depletion-enhancement type MOSFET, the same device could be used as a depletion mode and/or enhancement mode.
How can it be possible that the same equations could be true for both the modes?

Thank you.

Kind regards.

- - - Updated - - -

Hi,

Thanks for your reply.

In depletion-enhancement type MOSFET, the same device could be used as a depletion mode and/or enhancement mode.
How can it be possible that the same equations could be true for both the modes?

Thank you.

Kind regards.

PMOS enhancement type has -ve Vth and PMOS depletion type also has -ve Vth. How can we distinguish between them?

Thank you.

Kind regards.