Circuit Name and explication

[Algar_emi]

Hi. Can someone explain to me this FET circuit configuration? I guest it is a form of current source, does it have a name? I think Q1 is selected for the needed current. Q1 can be 2SK170 and Q2 can be 2SK246 for example.

Any help appreciated. Thanks.

 

[DUG]

Q1 / R3 sets the current...remains at a fairly constant Vds

Q3 dissipates the power...may vary significantly (depends on rest of circuit)

More stable set point

IMHO

🙂

 

[SY]

Much of the context is missing, but it sure looks like a cascode to me.

 

[DUG]

Yes, too much missing really...I thought it was a current source but it does not have to be that.

 

[Algar_emi]

Here more background to judge the function of the circuit.

 

[SY]

Yes, cascode.

 

[DUG]

Yes, cascode.

Current stability and reduction of frequency limitations due to Miller Effect.

🙂