DCDC Conversion Studies Status Report from Aachen Lutz

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 13 th, 2009

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: Ph. D student • Two diploma students: – Rüdiger Jussen (DC-DC converter studies) – Jennifer Merz (Analysis of the material budget) Katja Klein Status Report from Aachen 2

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 3

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 4

Work Plan from Mid 2008 • Investigation of system aspects of novel powering schemes – DC-DC conversion First round of system tests with comm. buck converters finished. – Serial powering? No concrete plans; concentrate on DC-DC conversion. • 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

System Test with DC-DC Converters • Results summarized by Lutz in October meeting http: //indico. cern. ch/get. File. py/access? contrib. Id=0&res. Id=0&material. Id=slides&conf. Id=41790 --- No converter --- Converter + 30 m Alu shielding --- 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-2009/003 “System Test Measurements with a DC-DC Conversion Powering Scheme for the CMS Tracker at SLHC” Katja Klein Status Report from Aachen 6

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 Ongoing. – Noise injection into DC-DC converters Not yet done, still planned. • 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 7

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 8

Noise Susceptibility Studies • Injection of I=70 d. B A (3 m. A) into power lines (2. 5 V, 1. 25 V, differential/common mode) • Results not quite as expected; current interpretation: APV 25 on-chip common mode subtraction is again hiding the real system response 2. 5 V, Diff. Mode Deconvolution mode; mean noise of one APV Deconvolution mode; noise of strip 512 l l i w s sult Mean noise of one APV; zoom Re t a d e ent xt e n the s e r p be Peak at around 6 -8 MHz seen for edge strips, but not in mean APV noise ? Katja Klein Status Report from Aachen . g n i t mee Noise of strip 512; zoom 9

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 Done. – PCB development PCB for SWREG 2 chip done; PCB development ongoing. – Magnetic field test Done. – Irradiation tests Currently covered by CERN. • Simulation of material budget of different powering schemes Katja Klein Status Report from Aachen 10

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 LTC 3568 buck converter; switching frequency configurable up to 4 MHz; in hands, to be tested Enpirion EQ 5382 D Katja Klein 3 cm LDO LTC 3026 Status Report from Aachen 11

Magnet Test • Tests performed with 7 T NMR-magnet at Forschungszentrum Jülich, close to Aachen • Enpirion converter, CERN SWREG 2, 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. 5 V m t x e en . g n i t ee th t a ted en s e r ep lb l i w ails Det Katja Klein Status Report from Aachen 12

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 13

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 14