Current conveyor as a voltage amplifier

[bcarso]

Originally Posted by smms73

Dado it looks very good
How about using those supertex depletion mosfet in place of the jfet's? They have higher early voltage than the 2sk170 at those low Vds. I just do not know if they are noisier.
I will buy some of this deplection mosfets for triyng some ideas.
You can also cascode the main current sources for higher output impedance of the ccs. But your regulator is very good as it is.

They are a bit noisier, especially at low frequencies.

[dadod]

Originally Posted by keantoken

There is a way to find out.

I will try to explain why I think it was not good idea at least for my shunt regulator.
1. I whant to regulate both sides + and - with one trimer for that.
2. I tried not to uze zener diode as reference(used in Borbely simple shunt reg) as that defeat poit 1.(and it is noisier).
3. Output impedance is low enough, a wires could input higher impedance.
4. To spare a diodes is not so important as above points.
dado

[dadod]

Originally Posted by smms73

Dado it looks very good
How about using those supertex depletion mosfet in place of the jfet's? They have higher early voltage than the 2sk170 at those low Vds. I just do not know if they are noisier.
I will buy some of this deplection mosfets for triyng some ideas.
You can also cascode the main current sources for higher output impedance of the ccs. But your regulator is very good as it is.

Thanks ssms73,
I have a bunch of different small jfets and only TO220 supertex type, and they are noisier as bcarso pointed out.
Cascoding of the ccs, I think, is not very needed.
dado

[smms73]

Originally Posted by bcarso

They are a bit noisier, especially at low frequencies.

I was afraid of that. anyway I will buy some to experiment.

[smms73]

Originally Posted by dadod

Cascoding of the ccs, I think, is not very needed.
dado

Walt jung have writing some articles about current sources to use with regulators.

Services

[bcarso]

Originally Posted by smms73

I was afraid of that. anyway I will buy some to experiment.

Walt's recommendation was the reason I tried them and tested them in fact. They are not too bad, but there is no guarantee, no specification for noise, and it is highly process-dependent. But those Supertex parts I tried were not as bad as I feared and would be quite adequate for many situations (like plate loads for hybrid tube circuits, which was my application at the time).

Brad

[keantoken]

You're right Dadod, I didn't think about how the zener would act as a reference. I'm a total go for the regulator as it is, FWIW. Keep up the good work.

[dadod]

Originally Posted by keantoken

You're right Dadod, I didn't think about how the zener would act as a reference. I'm a total go for the regulator as it is, FWIW. Keep up the good work.

Thanks Kean, I appreciate your support.

[dadod]

Discussion, in an other thread, about the need to have SUPER HIGH bandwidth was the reason to do some FFT simulation at 20kHz, 100kHz and 1MHz.
Here are the simulations only, I hope that the real result will be not far from it.
dado

[MiiB]

Sergio.. would it be possible to make something like the circuit in post #180 with balanced in..??