I am wondering that can we use/put GaN based MOSFET as pass element in linear voltage regulator instead Si based BJT ?

 

The main benefit of GaN technology is faster switching times due to lower gate charges (Qg) leading to significantly lower switching losses. The Rds figures are broadly similar to Si/SiC MOSFETs but have a sharper transition relative to Vgs which makes them less suitable for linear operation.

 

I am wondering that can we use/put GaN based MOSFET as pass element in linear voltage regulator instead Si based BJT ?

Why?
I see no apparent advantage for a GaN MOSFET in this application over a silicon MOSFET or BJT.

 

I am wondering that can we use/put GaN based MOSFET as pass element in linear voltage regulator instead Si based BJT ?

Yes, you can but it is like buying a race car to sit in the garage and listen to the radio and never drive.

 

The principle of ALL linear regulators is converting (V_in - V_out) * I_out into heat. So why should you use an expensive GaN-FET as a variable resistor if this can be done with a cheap BJT.

 

The application area has some radi ations. That's why I was thinking of GaN based device.

 

The application area has some radi ations. That's why I was thinking of GaN based device.

interesting ,
is the hihh current analog circuit of the regulator suseptable to radiation based disruptions .?

 

The GaNs that I use do not have a good way to heatsink them. They were designed to be 100% on or 0% on and nothing in-between.
2N3055 60V 15A transistor.

Below: EPC2030 40V 53A GaN MOSFET. The EPC2030 is about the size of the mounting hole in the 2N3055, (4.4mm). This picture is 4.6 x 2.6mm total while the lead on the 2N3055 is 1mm x 12mm.

----edited----
GaN comes in many different shapes. I have some in TO-3P but the lead length was too long. The part wants to oscillate because of the inductance in the leads. My first try made a 300mhz power oscillator.

 

So can you find a GaN transistor that can be heat-sunk to dissipate the regulator power at maximum current and voltage drop?

 

Can EPC2030 or similar GaN MOSFET be used as a pass element in linear voltage regulator ?

 

So can you find a GaN transistor that can be heat-sunk

 

View attachment 365565

That is a hybrid transistor with a Si MOSFET, so likely would not be radiation resistant as the OP wants.

 

Can EPC2030 or similar GaN MOSFET be used as a pass element in linear voltage regulator ?

No.
You need one that can be mounted on heat-sink, unless your current and In-Out voltage drop requirements are very low.

 

Can EPC2030 or similar GaN MOSFET be used as a pass element in linear voltage regulator ?

Yes, but most GaNs that I have used are surface mount and are hard to get the heat out of them.
At first the GaNs came in through hole packages, but they are out of production because the packages were never designed to run at these speeds.
I used this package a lot. There is no place to connect a heat sink. The PCB is the heatsink.

 

Do we always need heat sink even if the power dissipation is under 2W ?

 

Do we always need heat sink even if the power dissipation is under 2W ?

the data sheet of any package will stipulate the die temprature rise per watt and the maximum temprature of the die .

 

Can we made a custom desin of linear regulator internal components on a small PCB card ?

 

Again, apart from heat sink requirement, can a GaN based MOSFET be used instead BJT pass element in linear voltage regulator custom design with all individual internal components on the small PCB ?

 

Again, apart from heat sink requirement, can a GaN based MOSFET be used instead BJT pass element in linear voltage regulator custom design with all individual internal components on the small PCB ?

yes

 

Can we made a custom desin of linear regulator internal components on a small PCB card ?

yes