July 8 2003, FPD integration meeting, Carlos Avila

1

• FPD noise pattern on AFE is due to TPP layout
• Location of GNDA layer seems to be the cause of
  getting noise on AFE.

TPP layer design
One channel basic circuit
2
Tests on AFE phase 5 stand
Primary ground out

• Used an empty TPP board and added transformers
  to only one ribbon connector.
• Took out the primary ground of transformers.
• extended one ribbon cable from pw08 to phase 5
  test stand
• Tested different ground configurations

3
PW08 cable connected to MCM4 on phase 5 stand
9.0
MCM4
2.5
MCM4
3.5
MCM4
4
RMS on MCM2 with pw08 cable connected on MCM4
10.0
MCM2
1.6
MCM2
3.0
MCM2
5
Another Possibility is not connecting primary
ground to any layer, just connect primary ground
to the ground on input ribbon cable.
4.0
MCM4
MCM4
July 3
July 6
2.0
MCM2
6
SUMMARY AND CONCLUSIONS

• Two possible TPP configurations to reduce noise
• Not connecting primary ground to a layer plane
  reduces noise pickup on different lines.
• Waiting for Collision Hall access to perform
  tests at Pw08
• If we want new boards made, it would take about
  one week to get new Gerber file if we just swap
  VBB and GNDA layers. It would take about a month
  to make major modifications time of making the
  boards time to stuff them.

We could also just rewire the board