1. F. Arteche, C.Esteban, (ITA) I.Vila(IFCA) Electronics integration studies for CMS tracker upgrade

2. 1 de 33 CMS / ATLAS Power working group Geneva, 31 March 2010 OUTLINE 1. Introduction 2.R&D project for SLHC: –Working Packages 3. WP1: Power network impedance characterization –System description –Noise emission at system level Output impedance Input impedance Granularity 4. WP4: Power network impedance characterization 5.Future work 6. Conclusions

3. 2 de 33 CMS / ATLAS Power working group Geneva, 31 March 2010 1. Introduction Main characteristics of the DC-DC converter powering scheme: – Several noise sources close to FEE-Sensor DC-DC power converter, MT & HV line & Structure –High magnetic field inside tracker volume No optimal DC-DC power converter design –High switching frequency Radiation (Near-field and Far-field) –New FEE design Sensitive to sensor & power line connection (LF & HF) A large R&D effort is planned and taking place to develop a DC- DC switching converter to operate under high magnetic field with low electromagnetic emissions –GREAT effort form Cern & Aachen But it is important to have a R&D plan on EMC issues to conduct studies on the tracker detector at the system level To ensure the correct integration of SLHC tracker at system level

4. 3 de 33 CMS / ATLAS Power working group Geneva, 31 March 2010 2. R&D project for SLHC EMC immunity studies for CMS tracker upgrade - 9.04 –IFCA & ITA – Approved by CMS MB on 20 th of November Long & detailed review process (Tracker & CMS upgrade MB ) –Proposal sent – 3 June Proposal was welcomed because covers a critical integration issue for the detector - Good comments from reviewers First stage of the EMC strategy The main goal of the project is: –To define preliminary rules to ensure the integration of main components (Detector, FEE, Power network and DC-DC ) –To define design strategies that allow increasing the immunity of the Detector-FEE unit. It is divided in two parts: –Noise coupling mechanisms –New high immunity systems to EM noise

5. 4 de 33 CMS / ATLAS Power working group Geneva, 31 March 2010 2.1 R&D project for SLHC: Working Packages WP 1: Power network impedance characterization –The aim of WP1 is to define and characterize the impedances connected to the DC-DC power converters It defines the noise (conducted and radiated) levels emitted by the DC-DC power converters AT SYSTEM LEVEL Characterization of the electromagnetic environment –Impedances ( FEE & Power Bus) –Multiple units ITA will conduct this WP (Open ) WP 2: Noise propagation effects in power network –The aim of WP2 is to define the key points that allow designing the power network to minimize the effects of noise currents generated by DC-DC coveters. PCB or Twisted pair cables –ITA & IFCA will conduct this WP Very close collaboration with FERMILAB- M.Johnson

6. 5 de 33 CMS / ATLAS Power working group Geneva, 31 March 2010 2.2 R&D project for SLHC: Working Packages WP 3: Noise immunity test in FEE prototypes –The aim WP3 is to define the FEE immunity on prototypes: Impact of integration strategies in the overall design. Conducted & radiated test (ITA facilities). –ITA & IFCA will conduct this WP Prototype development (several possibilities) WP 4: Validation of EM immune OFS for temperature, magnetic field and strain: Effect on overall EM noise –The purpose of WP4 seeks out the implementation of OFS to substitutes previous measuring systems based on cooper cables and increase the immunity of tracker system. Different methods for attaching the fibres to carbon composites supports Architectures for sensor distribution network EMC factor measurement –Noise emissions and immunity with conventional electrical technologies versus Optical Fiber Sensors. –IFCA will conduct this WP

7. 6 de 33 CMS / ATLAS Power working group Geneva, 31 March 2010 3. WP1: Power network impedance characterization The first stage of the integration studies It will help to define preliminary rules to ensure the integration of main components –Power Network design strategies –Detector - FEE – PS connection –Chip design –DC-DC power converter It is very important to define and characterize the impedances connected to the DC-DC power converters –It defines the noise (conducted and radiated) levels emitted by the DC-DC power converters at system level Filters degradation This characterization will be focused on integration issues at system level and not on DC-DC converter design issues. –It is complementary to the work developed by other groups..

8. 7 de 19 3.1 WP1: PN impedance characterization: System There are several layout proposal for system layout –Prop. 1 Susanne Kyre, Dean White First results very encouraging G. Hall´s talk DEC 09

9. 8 de 33 3.1 WP1: PN impedance characterization: System There are several layout proposal for system layout. Prop 2 M. Jonhson´s Talk CMS upgrade WS 2009 DC-DC

10. 3.1 WP1: PN impedance characterization: System 9 de 33 CMS / ATLAS Power working group Geneva, 31 March 2010 All proposals are different but in terms of impedances have common points Input &Output

11. Input –Low impedance in DM Large amount of capacitors connected in the PN –Ej: Old Tracker : several hundreds uf –Low impedance in CM Possible grounding connection is under analysis but.. –Detector or negative line has to be grounded due to safety reasons & performance At high frequency “stray capacitance “starts to play an important role 10 de 33 CMS / ATLAS Power working group Geneva, 31 March 2010 3.1 WP1: PN impedance characterization: System Z BUS DC BUS DC

12. Output –Low impedance in DM mode Decoupling capacitors –Each DC-DC supplies to several chips –CM impedance will be defined by stray capacitances Cooling blocks close to the DC-DC Frame support is made of Carbon Fiber –Similar to copper above 500 kHz. 11 de 33 CMS / ATLAS Power working group Geneva, 31 March 2010 3.1 WP1: PN impedance characterization: System

13. Pspice model has been develop to study the impedance effect in noise emissions at system level –Frequency domain –Time domain. DM & CM models has been studied – Today DM Model based on DC-DC converters models developed by CERN & K. Aachen –Noise studies –DC-DC converter ( 10 V-2.5V / 1 to 5 A) 12 de 33 CMS / ATLAS Power working group Geneva, 31 March 2010 3.2 WP1: PN impedance characterization: Noise Emissions at system level

14. The DM output emissions from DC-DC are mainly defined by: –Inductor –Pi – filter However the load impedance plays an important role in the noise emissions –Load has been characterized by a current source with a capacitor plus a resistance in parallel. A frequency characterization of filter performance respect several impedances has been studied (real vs normalized impedances) –10mΩ, 50Ω, 100Ω 13 de 33 CMS / ATLAS Power working group Geneva, 31 March 2010 3.2 WP1: PN impedance characterization: Noise Emissions at system level : Output impedance

15. Filter performance –IL > 80 dB –HF increases due to filter inductance 14 de 33 CMS / ATLAS Power working group Geneva, 31 March 2010 3.2 WP1: PN impedance characterization: Noise Emissions at system level : Output impedance Z=10m Ohms Z=150 Ohms Z=50 Ohms

16. The output DM noise emission depends strongly on the load impedance (Iout=3A). –Expected impedance bellow 0.1 ohms –Possible noise emissions >100mA Pkk 15 de 33 CMS / ATLAS Power working group Geneva, 31 March 2010 3.2 WP1: PN impedance characterization: Noise Emissions at system level : Output impedance

17. Spectrum profile is very similar but shifted between 40 and 80 dB. 16 de 33 CMS / ATLAS Power working group Geneva, 31 March 2010 3.2 WP1: PN impedance characterization: Noise Emissions at system level : Output impedance

18. It is expected to connect the DC-DC to FEE via short cables The output DM noise emissions has been evaluated for 3 cables of different length –10 cm, 0.5m and 1m –Iout=3A ; Zout=10mΩ Reference cable: – L=0.5uH/m (from old TK) Noise emissions –Max – 120 mA. pp –Min – few mA. pp 17 de 33 CMS / ATLAS Power working group Geneva, 31 March 2010 3.2 WP1: PN impedance characterization: Noise Emissions at system level : Output impedance

19. Spectra profile is very similar but shifted around 30 dB 18 de 33 CMS / ATLAS Power working group Geneva, 31 March 2010 3.2 WP1: PN impedance characterization: Noise Emissions at system level : Output impedance

20. The DM input emissions from DC-DC are mainly defined by: –Pi – filter But, again, the load impedance plays an important role in the noise emissions This impedance will be very low due to the large amount of Capacitor connected to the power network –Old tracker – More the 100 µf (more than 30 capacitors) Frequency characterization of filter performance respect several impedances is similar to the output –Filter performance degradation is expected –Input impedance may vary between 1mΩ - 1Ω 19 de 33 CMS / ATLAS Power working group Geneva, 31 March 2010 3.2 WP1: PN impedance characterization: Noise Emissions at system level : Input impedance

21. The DM input noise emission depends strongly on input impedance. –Expected Zin bellow 0.1 ohms –Possible noise – >80mA Pkk Zin 300 mA. 20 de 33 CMS / ATLAS Power working group Geneva, 31 March 2010 3.2 WP1: PN impedance characterization: Noise Emissions at system level : Input impedance

22. Spectrum profile is very similar but shifted around 40 dB. 21 de 33 CMS / ATLAS Power working group Geneva, 31 March 2010 3.2 WP1: PN impedance characterization: Noise Emissions at system level : Input impedance

23. The granularity of the detector also may have an impact in the noise emission level. The detector granularity defines: –Current consumption per DC-DC converter –Number of DC-DC converters connected to the same bus DM Noise emissions for two different scenario have been analyzed –Output current 1 to 5 A –DC-DC converters connected to the same bus 1 to 4 DC-DC converters –As a reference Input impedance & output impedance – 10 mΩ 22 de 33 CMS / ATLAS Power working group Geneva, 31 March 2010 3.2 WP1: PN impedance characterization: Noise Emissions at system level : Granularity

24. DM Input & output emissions of DC-DC converters has been analyzed –Three cases: 1 A, 3 A and 5 A –Zin=Zout=10 mΩ Input emissions –Noise increases Iout = 1 A – Noise : 20mA Iout = 5 A – Noise : 400mA Output emissions –Constant 23 de 33 CMS / ATLAS Power working group Geneva, 31 March 2010 3.2 WP1: PN impedance characterization: Noise Emissions at system level : Granularity Input Output

25. The spectrum content in DM at the input is similar but it is also shifted around 10 dB –Difference between 1 A and 5 A 24 de 33 CMS / ATLAS Power working group Geneva, 31 March 2010 3.2 WP1: PN impedance characterization: Noise Emissions at system level :Granularity

26. The noise emissions at the power network level has been analyzed –4 DC-DC converter connected in parallel –Synchronized switching frequency 25 de 33 CMS / ATLAS Power working group Geneva, 31 March 2010 3.2 WP1: PN impedance characterization: Noise Emissions at system level : Granularity DC

27. The spectrum content in DM at power network increases with the number of DC-Dc connected. –Difference between 1 DC-DC and 4 DC-DC A (10 dB) Similar scenario has been already observed in old tracker 26 de 33 CMS / ATLAS Power working group Geneva, 31 March 2010 3.2 WP1: PN impedance characterization: Noise Emissions at system level : Granularity

28. This lead to high noise emission level at power network level –4 DC-DC / 5 A → 1.6 A at 1 MHz !!!!!! 27 de 33 CMS / ATLAS Power working group Geneva, 31 March 2010 3.2 WP1: PN impedance characterization: Noise Emissions at system level : Granularity

29. 28 de 33 CMS / ATLAS Power working group Geneva, 31 March 2010 4. WP 4: Validation of EM immune OFS for temperature, magnetic field and strain: High immunity system New tracker system will generate a large amount of noise inside the tracker volume Easier coupling path Filtering is more complex High noise at power network level The study or design of new systems insensitive to EM noise to measure temperature, strain or magnetic field will increase the robustness of FEE to EM noise The use of optical fibre sensors (OFS) to be used as temperature and strain probes will increase the immunity of tracker system. They are very well known in aerospace and aeronautics This type of sensors is Not sensitive to EM fields, HV and transients. Light – weight, miniaturized and flexible Non-interfering, low-loss, long-range signal transmission

30. 29 de 33 CMS / ATLAS Power working group Geneva, 31 March 2010 4. WP 4: Validation of EM immune OFS for temperature, magnetic field and strain: High immunity system Fibre Bragg Grating (FBG ) optical transducer is the most common transducer to measure strain and temperature –A light is sent via the optical fibber to the transducer and the diffracted wavelength is measured –Diffracted wavelength depends on FBG geometry, that is affected by stress and temperature. Stress Temp

31. 30 de 33 CMS / ATLAS Power working group Geneva, 31 March 2010 4. WP 4: Validation of EM immune OFS for temperature, magnetic field and strain: High immunity system The FBG sensors allows: –Multiplexing capability – (Sensor Networks) –Embedding in composite material –(Smart structures) –High and low Temperatures ( 4 k – 900 ºC). –Durable to high strain –It is necessary only one fibre to read out strain & temperature

32. WP1: Impedance effects –Analyzed CM noise emissions –System test for integration issues under development Measure CM & DM emissions respect several impedances and loads WP4: Validation of EM immune OFS –Different methods for attaching the fibres to carbon composites supports –Architectures for sensor distribution network –EMC factor measurement –Noise emissions and immunity with conventional electrical technologies versus Optical Fibre Sensors. 31 de 33 CMS / ATLAS Power working group Geneva, 31 March 2010 5. Future work

33. ITA & IFCA has recently started a new project focused on integration issues R& D project divided in 4 WP WP1 & WP4 has started WP1 focused on impedance effects on noise emissions –First results focused on DM noise –Strong dependence of DM noise emissions respect Input & output Impedance Granularity WP4 focused on development of high immunity systems –Substitute the Temp, strain and magnetic monitoring lines for other based on optical fiber. 32 de 33 CMS / ATLAS Power working group Geneva, 31 March 2010 6. Conclusions

34. 33 de 33 CMS / ATLAS Power working group Paris- France, 23 September 2009 BACKUP SLIDES

35. But why the noise does not increases at the output ? The output current has the same shape –Only they are shifted a certain DC value defined by current consumption –AC shape it is defined by duty cycle and converter parameters However, the input current has different shape –Spectra content is different 34 de 33 CMS / ATLAS Power working group Geneva, 31 March 2010 3.2 WP1: PN impedance characterization: Noise Emissions at system level : Granularity Input Output