Noise and Capacitor M.Friedl, R.Thalmeier, H.Yin (HEPHY Vienna) 24 September 2015

M.Friedl, R.Thalmeier, H.Yin: Noise and Capacitor2 Trieste: “increase C as much as possible”

Capacitor  Presently: 10nF / 500V (0805 size)  New: 100nF / 200V (0805 size)  TDK CGJ4J3X7T2D104K125AA  Reel (2000 pcs.) ordered last Friday, delivered on Tuesday  Voltage rating reduction is not an issue, because with new cap we can still bias up to 400V  DSSDs do not withstand much more than 200V 24 September 2015M.Friedl, R.Thalmeier, H.Yin: Noise and Capacitor3

Test Setup with FADC System  Sine generator injects CM noise via transformer  Tested with DESY modules (single DSSD) and L5.903 (class B ladder) 24 September 2015M.Friedl, R.Thalmeier, H.Yin: Noise and Capacitor4

Results of L3 (Noise Injected in n-Side) 24 September 2015M.Friedl, R.Thalmeier, H.Yin: Noise and Capacitor5  Chip average Strip RMS (without CMC) vs. noise frequency  With 10nF  With 100nF

Results of L5 (Noise Injected in n-Side)  Chip average Strip RMS (without CMC) vs. noise frequency  With 10nF  With 100nF 24 September 2015M.Friedl, R.Thalmeier, H.Yin: Noise and Capacitor6

Results of L6 (Noise Injected in L5 n)  Significant effect also on L6 module (even though injection is still done on L5 n-side)  Both modules are attached to same DC/DC converters 24 September 2015M.Friedl, R.Thalmeier, H.Yin: Noise and Capacitor7

Results of L5.903 FW (Noise Injected in n) 24 September 2015M.Friedl, R.Thalmeier, H.Yin: Noise and Capacitor8  Chip average Strip RMS (without CMC) vs. noise frequency  With 10nF  With 100nF

Other Results  APV hangs up above certain noise injection level  Fully reproducible  Threshold is increased by a factor of ~10 when changing 10nF  100nF 24 September 2015M.Friedl, R.Thalmeier, H.Yin: Noise and Capacitor9

Source Test with FW Module of L5.903 (1/2)  p-side: 24 September 2015M.Friedl, R.Thalmeier, H.Yin: Noise and Capacitor10 10nF 100nF

Source Test with FW Module of L5.903 (2/2)  n-side: 24 September 2015M.Friedl, R.Thalmeier, H.Yin: Noise and Capacitor11 10nF 100nF

Summary  Noise immunity can be significantly improved by increasing 10nF  100nF  Shown in all noise injection measurements  No impact on source measurement without noise injection  Recommendation:  Use 100nF caps for Origami flex assembly (received by Toru today)  Replace 10nF with 100nF on hybrid boards (delivered to Pisa, on the way to Melbourne)  Cap locations on Origamis and hybrid boards are specified on the following pages 24 September 2015M.Friedl, R.Thalmeier, H.Yin: Noise and Capacitor12

Capacitor Location (1/4)  Origami_-z and _ce 24 September 2015M.Friedl, R.Thalmeier, H.Yin: Noise and Capacitor13  Origami_+z

Capacitor Location (2/4) 24 September 2015M.Friedl, R.Thalmeier, H.Yin: Noise and Capacitor14  L3 hybrid, P side  L3 hybrid, N side

Capacitor Location (3/4) 24 September 2015M.Friedl, R.Thalmeier, H.Yin: Noise and Capacitor15  L6_+z (FW) hybrid, P side  L6_+z (FW) hybrid, N side

Capacitor Location (4/4) 24 September 2015M.Friedl, R.Thalmeier, H.Yin: Noise and Capacitor16  L6_-z (BW) hybrid, P side  L6_-z (BW) hybrid, N side