Table of Contents
Advertisement
Specifications
2.4.2. Max. output broadband noise voltage
Normally the noise is given input referred, so to speak, it can be compared to the source signal
levels. For timing applications it is often more depicting to plot the total output noise of an
amplifier.
In the following scope pictures the output noise voltage of our TAx-amplifiers is accumulated over
10,000 waveforms corresponding to about 40 minutes of measurement time. Used was a
TEK11801C digital sampling scope with a SD22 12.5GHz sampling head. Thus, the displayed
noise voltage is accumulated over a long period and also over the full bandwidth of each
amplifier. The TAx's inputs were shortened, i.e. ZSource = 0Ω.
On the right side of each plot you can see a (red colored) histogram of all the voltage samples in
the respective picture. This gives the probability distribution of the noise voltage levels. And, you
can find some analysis data on the respective voltage distribution: Mean = average value, RMSΔ
= σ = standard deviation, PkPk = Peak-to-Peak voltage = max. – min. sample voltage, μ ± 1σ =
percentage of samples that fall within ±1 standard deviation of the mean (.±2σ, ±3σ respectively).
Sampling Head alone, 2mV/div
ComTec GmbH
2-4
Advertisement
Table of Contents
