CDC 19 12 2007

Interposer, preAmp, and signal cable

This is the continuation of CDC_12_12_2007.

Thanks to Fernando we have a new reference measurement; he measured the noise of the interposer+preAmp+signal cable: his measurement is shown in figure 1.

figure 1: interposer+preAMp+signal-cable (taken from Fernando's report) (x-y divisions: 20 ns - 20 mV).

The differential signal was measured with the cable between the CDC-straw-wire and the HV-distribution board disconnected on the CDC side. The measured signal is shown in figure 2.

figure 2: HV-board+preAmp+signalcable signal (pink) with cable between CDC and HV distribution board disconnected on the CDC side.

No oscillations are observed! If one compares to figure 1 the comparison is reasonable, but I think Fernando has a better oscilloscope!

For the sake of completeness, the cable between the CDC and the HV distribution board was also disconnected on the side of the HV-board, this signal can be seen in figure 3.

figure 3: HV-board+preAmp+signalcable signal (pink) with cable between CDC and HV distribution board disconnected on the HV distribution board side.

Again, no oscillations.

Conclusion: the oscillations are caused by the input signals on the preAmp