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Double gate Mosfets

Hi all!

I need to build an ultra low noise cascode amplifier and I want to use a double gate mosfet to gain better performances with respect to jfets. I need a very low gate leakage current, because it worsens the SNR.

I found some interesting components made for RF purposes by NXP, but all have protection diodes and also a bias network integrated in the package. I need to find a mosfet with naked gates. I know they're very sensitive to ESDs, but I need very low leakage and I can't tolerate the leakage of the protection diodes.

Can someone help me? Thanks! Marco

Reply to
marcodedin
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What frequency? What bandwidth?

John

Reply to
John Larkin

Try Calogic. They make small signal MOSFETs without protection diodes.

Reply to
MooseFET

Hi John, thanks for replying. Ok, the mosfet has to be used in a charge sensitive preamplifier configuration. At the present moment I'm using a jfet before an op-amp with a drain resistance of 1Kohm, but I want to try a double gate mosfet to be able to remove the drain resistance which increases the drain current noise. If I use a double gate mosfet, I can obtain the desired drain current by biasing the first gate and applying the signal to the second one. The problem is that I need very low gate leakage current (to reduce noise), so the need for a mosfet without gate protection diodes.

This is all. I hope I've clarified the problem Thanks all :) MArco

Reply to
marcodedin

Thanks for the advice,

unfortunately they don't make double gate mosfets. I only found devices with the external bulk connection but the transconductance was too low. Thanks anyway :) MArco

Reply to
marcodedin

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