1. USBPix Readout System using FE-I4/A chip Status Update: Finalization of Threshold Tuning and Minor updates
Jimin Kim and Austin Piehl
Department of Physics
University of Washington

2. Table of Contents Established goals during last week
General Procedure for Threshold Tuning with reasonable dispersion (<30e) and improvement
Software Update and troubleshooting
What’s next?
Questions

3. Established Goals Last Week
Establish the General Procedure for Tuning Threshold to desired value with reasonable dispersion (<30e)
Optimize/Improve the final result by analyzing unhealthy pixels
Move on to ToT Scan
Major update on TeV Page
Update Software from to

4. General Procedure for Threshold Tuning
Global Tuning
DIGITAL_TEST
Strobe signal repeatedly injected straight to the discriminator
To check digital functionality/Data linkage and mask dead/unhealthy pixels
ANALOG_TEST
Strobe signal larger than threshold is injected repeatedly into the Analog cell
To check Analog functionality/Data linkage
THRESHOLD_SCAN
VCAL/PulsarDAC injects repeatedly various charges into analog pixel cell
To check threshold mean and dispersion
GDAC _TUNE
Changes global threshold parameter (Vthin_AltFine) and scans threshold for each step
Gives optimal value for Vthin_AltFine for global threshold adjustment
Repeat the GDAC_TUNE until there is no change in means

5. General Procedure for Threshold Tuning
Pixel Tuning
TDAC_FAST_TUNE
Roughly tunes the TDAC value of each pixel prior to Fine tuning
Binary search of TDAC register using different step sizes but skips the threshold scan
Creates the TDAC Map to be loaded in config file for pixel
TDAC_FINE_TUNE
Finely tunes the TDAC value of each pixel for uniformity of pixel thresholds
Binary search of TDAC register using different step sizes and also conducts threshold scan (<40mins)
Repeat TDAC_TUNE until there is no change in means and dispersion
Optimization
NOISE_SCAN
Runs at 10KHz trigger rate
Identifies pixels with too high noise occupancy and creates masks

6. Digital and Analog Test
Digital Test
Analog Test

7. After GDAC_TUNE (Target 3100e)
Threshold Scan
Before GDAC_TUNE
After GDAC_TUNE (Target 3100e)

8. Threshold Scan
After TDAC_FAST_TUNE (Target Threshold of 3100e)

9. Threshold Scan
After TDAC_FINE_TUNE (Target Threshold of 3100e)

10. Optimization/Improvement
Analysis on bad pixels
S-Curve of individual pixel
TDAC Map vs Threshold Map
Noise issue?
Some pixels hitting the boundary?
Solutions
Mask certain rows and columns
Column 0,78 and 79 and top rows
Create mask for certain range (e.g: 3000e<x<3200e)
Change the step sizes by changing TDACvbpf register

11. Pixel Analysis
TDAC Map

12. Pixel Analysis S-Curve for pixels <3000e

13. Pixel Analysis
S-Curve for Pixels 3100e
S-Curve for pixel 3000e

14. Threshold Scan (Before Optimization)

15. Threshold Scan (After Optimization)

16. Threshold Scan (After Optimization)
TDAC Map

17. Software Update Change log from 3.3.0 to 4.4.1.0
New drivers that support both 32bit and 64 bit
Fixed scan abort in case no enabled module is present in a group
Iref pads controlled from USbPixController can be inverted by configuration setting
Added BCID and LVID command histograms
DCS devices
Fixed issue of wrong index when adding DCS devices in rel . 4.0
New GPIB devices – added keithley 2700 and updated HP 34970A
Default current limit for USBPix burn-in regulators is 1.0 A for a SC set-up and 1.5A for a DC Set up

18. SilabUSB Driver Issue Fail to recognize the FPGA Board!
Cannot initialize the DCS objects and Controllers!

19. SilabUSB Driver Issue
David Leon’s suggestion which is installing driver manually using NIF file doesn’t seem to work
Manually installing the 32bit driver doesn’t work either

20. SilabUSB Driver Issue Solutions?
Wait for David Leon to fix the Setup file
Try to install the medium mode
Try installing on other machines (64 bits)

21. What’s Next?
Further optimization on threshold tuning with dispersion <30e
Finalization of general tuning process including ToT Scan
Run Noise Scan for masking certain pixels with high noise?
Move on to additional scans such as Crosstalk, Monleak…
Major update on TeV page
Successful software update to

22. Questions for future Q/A