Diff-amp 1GHz

[luky315]

I am looking for an Differential Amplifier with the lowest possible noise to amplify a small diff. signal (50R impedance, 1mVpp, 10MHz - 1GHz) at least 5x (10x prefered)
I found the LTC6401-20 which looks like a nice fit, but the noise is a bit to high (2.1nV/√Hz)
Can someone suggest a low noise part for this job?

[ycui7]

how about https://www.ti.com/lit/ds/symlink/lmh5401.pdf

[luky315]

Thanks! TI has some very interesting parts... LMH6554 looks also nice, it is slower, but with less noise.
ISL55210 is also surprisingly good according to the datasheet, I have never used Intersil / Renesas analog parts, maybee it is worth a try

[David Hess]

With only 1 millivolt peak-to-peak, you can use a two transistor differential amplifier with a pair of NPN RF transistors and no emitter series resistance.  Noise is set by the tail current, so get a couple of medium power ones and operate them at higher current.  Gain is proportional to tail current and collector load resistance.  Noise will be lower and speed will be higher than any integrated solution.