Attendance:

Conny, Philip, Bhavna, Kaz, Alex, Zongde, Xavier, Julian, Nolan, Chris, Lorenzo, Bojan, Angelo

Agenda items:

  1. Presentation on results for TID 


Presentations:

Initial Findings For ePixHR Prototype (Conny)


Lorenzo's notes:

Issues:

  1. Banding
    1. Tests that can be done:
      • TID: Can test ADC independently with external DAC voltage
      • Calibration team: Look at different pixels in the same column, they are connected to the same ADC. See if the missing parts are the same everywhere.
      • Calibration/TID: Charge injection scan.
    2. Banding shows up in Dionisio's data too.
  2. Linearity vs rates
    1. Shift observed in pedestals
    2. Angelo: suggest to run at higher rate, and optimize there. The fact that the pedestals in LG shift, seems that something is marginal in terms of timing.
    3. We can see the effect also in the lab
    4. ToDo:
      1. TID: figure out the exact history of the calibration, re-check timing and registers.
      2. Investigate charge injection, can we get close to 5kHz.
  3. Variation in linearity/switching point
    1. Lorenzo: there's a ping-pong with 2xS/H channels in between the pixel column and the ADC.
    2. Discussion of possible issues:
      1. Offset in Vthr of the pixel
      2. Offset in the CSA, that gets removed by CDS.
      3. Difference in S/H gain+offset, but doesn't explain the magnitude.
    3. Can we use charge injection?
    4. Can we use ADC Vcalibp to rule out if it's the S/H or the pixel?
  4. CompEn variation
    1. See bank structure
    2. Bojan: due to distribution
    3. Not too big of an issue in HR?
    4. Keep an eye out in UHR! Lorenzo: different implementation, we should be good with ~ns skew across whole matrix
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