Is there such thing as a Normally Closed Mosfet or transistor like as?

[Iraianbu]

Is there such thing as a Normally Closed Mosfet or transistor like as?

Is there such thing as a normally closed mosfet? or can I somehow make a circuit ? can I control circuit one functions like as a control logic voltage 3.3v or 5v. when I give logic normally closed circuit change to normally open?

 

[dick_freebird]

"depletion mode" is your search key. Many "RF" GaN, all GaAs and
silicon MESFET / JFET types are. You can find depletion mode Si
MOSFET discretes and dual-gate. I have worked in technologies
which had high, low, intrinsic and depletion VT on both N and PMOS.
Now that's a salad.

 

[Iraianbu]

"depletion mode" is your search key. Many "RF" GaN, all GaAs and
silicon MESFET / JFET types are. You can find depletion mode Si
MOSFET discretes and dual-gate. I have worked in technologies
which had high, low, intrinsic and depletion VT on both N and PMOS.
Now that's a salad.

Depletion type MOSFET cost is high. I need Low cost and Simple Circuit like as this DMOSFET.

 

[danadakk]

Easy to configure a tristate gate as hi Z for open, and either a low or high
logic level for closed....

Or level translators with tri state, or single gate logic....

https://www.ti.com/lit/sg/scyt129g/scyt129g.pdf?ts=1675614876607&ref_url=https%253A%252F%252Fwww.google.com%252F

Regards, Dana.

 

[crutschow]

A P-MOSFET with the source connected to V+ and the drain as the output will be on when the gate is low (ground), giving a high-side switch.
Will that do what you want?

 

[dick_freebird]

If you mean, as the original post, that the transistor itself
should conduct without imposing a different bias voltage to
it, then complex circuits don't fit that frame.

But maybe it's a frame problem.

 

[stenzer]

Hi,

Depletion type MOSFET cost is high.

what are you design constraints e.g. current, voltage ratings, high-side or low-side application? You also can create the desired function with two transistors e.g. a N-MOSFET and P-MOSFET or even BJTs.

BR