Schmocki
Junior Member level 2
Hi,
as the dynamic range of a variable attenuator built with a JFET is dependent on the pinch off voltage (I know about the increasability by feeding back part of the drain voltage to the gate) I am looking for a JFET with a pinch off voltage being as high as possible (10V and up are very welcome, 6.5V should be something I can start with.
Specification does not have to be 10V minimum as I could buy a few more devices and select for high Vp.
Of course it should also have low noise (especially flicker noise) as I would not want to loose the dynamic range I have won by being able to process higher levels to the fact that I can not use the lower levels anymore because of too high a noise voltage.
RdsOn at Vgs=0V should be around 25 to 100 ohms, while higher values are not that critical as I could parallel a few devices.
JFETs with lower RdsOn might also work if Vp is high enough.
Many thanks in advance for any suggestions.
Schmocki
as the dynamic range of a variable attenuator built with a JFET is dependent on the pinch off voltage (I know about the increasability by feeding back part of the drain voltage to the gate) I am looking for a JFET with a pinch off voltage being as high as possible (10V and up are very welcome, 6.5V should be something I can start with.
Specification does not have to be 10V minimum as I could buy a few more devices and select for high Vp.
Of course it should also have low noise (especially flicker noise) as I would not want to loose the dynamic range I have won by being able to process higher levels to the fact that I can not use the lower levels anymore because of too high a noise voltage.
RdsOn at Vgs=0V should be around 25 to 100 ohms, while higher values are not that critical as I could parallel a few devices.
JFETs with lower RdsOn might also work if Vp is high enough.
Many thanks in advance for any suggestions.
Schmocki