1. DC-DC Conversion Studies – Status Report from Aachen
Lutz Feld, Rüdiger Jussen, Waclaw Karpinski, Katja Klein, Jennifer Merz, Jan Sammet
1. Physikalisches Institut B, RWTH Aachen University
Tracker Upgrade Power WG Meeting
February 13th, 2009

2. Status Report from Aachen
Personal
Lutz Feld: team leader
Waclaw Karpinski: electronics engineer
plus electronics workshop team
Katja Klein: Helmholtz Alliance fellow (4-years from April 08)
Jan Sammet: PhD student
Two diploma students:
Rüdiger Jussen (DC-DC converter studies)
Jennifer Merz (Analysis of the material budget)
Katja Klein
Status Report from Aachen

3. Status Report from Aachen
Funding
We have joined the SLHC-PP project of the EU FP-7 program (Work Package 8: Tracking detector power distribution)
In Germany, next 3-year BMBF funding period starts in July 2009
Have applied for invest money and positions
First feedback in May
Katja Klein
Status Report from Aachen

4. Status Report from Aachen
Work Plan from Mid 2008
Investigation of system aspects of novel powering schemes
DC-DC conversion
Serial powering?
Noise susceptibility measurements
Noise injection into silicon strip modules
Noise injection into DC-DC converters
Contribute to the development & characterization of magnetic field tolerant and radiation hard DC-DC buck converters, in coll. with CERN PH-ESE group
Duplicate CERN test-stand for converter noise characterization
PCB development
Magnetic field test
Irradiation tests
Simulation of material budget of different powering schemes
Katja Klein
Status Report from Aachen

5. Status Report from Aachen
Work Plan from Mid 2008
Investigation of system aspects of novel powering schemes
DC-DC conversion
Serial powering?
Noise susceptibility measurements
Noise injection into silicon strip modules
Noise injection into DC-DC converters
Contribute to the development & characterization of magnetic field tolerant and radiation hard DC-DC buck converters, in coll. with CERN PH-ESE group
Duplicate CERN test-stand for converter noise characterization
PCB development
Magnetic field test
Irradiation tests
Simulation of material budget of different powering schemes
First round of system tests with comm. buck converters finished.
No concrete plans; concentrate on DC-DC conversion.
Katja Klein
Status Report from Aachen

6. System Test with DC-DC Converters
Results summarized by Lutz in October meeting
--- No converter
--- Converter
--- Converter + 30m Alu shielding
--- Converter + LDO
--- Converter + LDO + 30m Alu shielding
 Noise of Enpirion converters can be controlled by combination of shielding and filtering (LDO).
Studies with commercial buck converters documented in Jans thesis CMS TS-2009/ “System Test Measurements with a DC-DC Conversion Powering Scheme for the CMS Tracker at SLHC”
Katja Klein
Status Report from Aachen

7. Status Report from Aachen
Work Plan from Mid 2008
Investigation of system aspects of novel powering schemes
DC-DC conversion
Serial powering?
Noise susceptibility measurements
Noise injection into silicon strip modules
Noise injection into DC-DC converters
Contribute to the development & characterization of magnetic field tolerant and radiation hard DC-DC buck converters, in coll. with CERN PH-ESE group
Duplicate CERN test-stand for converter noise characterization
PCB development
Magnetic field test
Irradiation tests
Simulation of material budget of different powering schemes
Ongoing.
Not yet done, still planned.
Katja Klein
Status Report from Aachen

8. Noise Susceptibility Studies
Goal: identify particularly critical bandwidth(s) for converter switching frequency
Bulk current injection test-stand has been set up (Rüdiger)
Katja Klein
Status Report from Aachen

9. Noise Susceptibility Studies
Injection of I=70dBA (3mA) into power lines (2.5V, 1.25V, differential/common mode)
Results not quite as expected; current interpretation: APV25 on-chip common mode subtraction is again hiding the real system response
2.5V, Diff. Mode
2.5V, Diff. Mode
Deconvolution mode;
mean noise of one APV
Deconvolution mode;
noise of strip 512
Results will be presented at the next meeting.
Peak at around 6-8MHz seen for edge strips, but not in mean APV noise
Mean noise of one APV;
zoom
Noise of strip 512;
zoom ?
Katja Klein
Status Report from Aachen

10. Status Report from Aachen
Work Plan from Mid 2008
Investigation of system aspects of novel powering schemes
DC-DC conversion
Serial powering?
Noise susceptibility measurements
Noise injection into silicon strip modules
Noise injection into DC-DC converters
Contribute to the development & characterization of magnetic field tolerant and radiation hard DC-DC buck converters, in coll. with CERN PH-ESE group
Duplicate CERN test-stand for converter noise characterization
PCB development
Magnetic field test
Irradiation tests
Simulation of material budget of different powering schemes
Done.
PCB for SWREG2 chip done; PCB development ongoing.
Done.
Currently covered by CERN.
Katja Klein
Status Report from Aachen

11. Status Report from Aachen
PCB Development
Aim for compactness and low mass
Study possibilities for efficient low mass shielding (e.g. Parylene-coating)
Study and improve noise filtering
First prototype being characterized
New PCBs expected for April
In addition: PCB with LTC3568 buck converter; switching frequency configurable up to 4MHz; in hands, to be tested
3cm
LDO LTC3026
Enpirion EQ5382D
Katja Klein
Status Report from Aachen

12. Status Report from Aachen
Magnet Test
Tests performed with 7T NMR-magnet at Forschungszentrum Jülich, close to Aachen
Enpirion converter, CERN SWREG2, LBNL charge pump tested
both versions with air-core and ferrite coils
Result: converters with air-core inductors and charge pump worked fine; converters with ferrite inductors stopped working or lost their efficiency
Uout = 2.5V
Details will be presented at the next meeting.
Katja Klein
Status Report from Aachen

13. Status Report from Aachen
Work Plan from Mid 2008
Investigation of system aspects of novel powering schemes
DC-DC conversion
Serial powering?
Noise susceptibility measurements
Noise injection into silicon strip modules
Noise injection into DC-DC converters
Contribute to the development & characterization of magnetic field tolerant and radiation hard DC-DC buck converters, in coll. with CERN PH-ESE group
Duplicate CERN test-stand for converter noise characterization
PCB development
Magnetic field test
Irradiation tests
Simulation of material budget of different powering schemes
 Presentation by Jennifer
Katja Klein
Status Report from Aachen

14. Status Report from Aachen
Summary & Outlook
Simulation studies are far advanced  presentation today
Magnet test done
Noise injection into modules to be finished
PCB development continues; focus on low mass, low noise, shielding
System test measurements are restarting
Development of test-stand to study systematically the coupling of noise from air-core inductors to the modules
Feedback from funding agency needed for longer timescale planning!
Katja Klein
Status Report from Aachen