Current Mirrors with a Ratio > 1:1

[caledonia]

Hello,

could you please tell me if there are current mirrors in the market with a ratio more than 1:1?

The matched transistors that I found are identical (1:1) or are destined for very hight currents. I need to amplify a photocurrent.

I found the TL021 of TI, but they are not produced anymore

Of course there is also the alternative to realize it myself with transistors having a proportional surface, but the noise will be to high I think.

I would be very grateful if you know an anlternative already on the market.

Thank you!

 

[FvM]

I don't think that current mirrors are suitable to amplify or buffer a small photo current, if noise is critical.

 

[crutschow]

Typically small photocurrents are amplified by a low noise op amp configured as a transconductance (current amplifier) circuit.

 

[caledonia]

Yes the first circuit I developped is built with a transimpedanceamplifier.
I'm just looking for alternatives. I thought about the amplifying currentmirrors. But this solution is only worth it when the transistors are matched with only the ratio >1.

Thank you!

 

[FvM]

Apart from the availablility of discrete current mirror components, you can calculate the cicrcuit's noise properties.