14 th CBM Collaboration Meeting Split 2009 Status of Front End Electronics N-XYTER PCB & Power Supply Volker Kleipa, GSI Darmstadt

14 th CBM Collaboration Meeting Split 2009 Topics Investigations in DC power supplies ➲ DC/DC step down converter test ➲ Alternative DC step down design NYXTER FEB_D ➲ N-XYTER PCB Requirements for FEB_D ➲ N-XYTER PCB Cooling Plate ➲ FEB_D N-XYTER Cooling ➲ N-XYTER FEB_D PCB Status

14 th CBM Collaboration Meeting Split 2009 DC/DC step down converter test First tests done with a supply supported by Floeth Elektronik Supply spec. was 15V to 3.3V, single phase step down DC/DC converter,equipped with an air coil switched at 150KHz, no additional filter. Environment was 1.5T generated with ALADIN magnet at GSI Load 0.5Ohm Results: + Supply is working at 1.5T +Efficency independent of magentic field - 70% efficency only - High noise generation independent from magentic filed Our Requirements for switched DC/DC converters: High effincency (low local heat generation) to replace linear regulators Up to 2T magnetic fields means no ferrite shielded components Low Noise distribution

14 th CBM Collaboration Meeting Split 2009 Alternative DC step down design Multiphase design Further investigations will be the testing some Reference desings I.e. IR design IRDCiP2002-C, Converter 12V to 3.3V, >82% eff., 120A output with 12mVp-p ripple 1MHz/phase Coils with only 300nH will be replaced by air coils.

14 th CBM Collaboration Meeting Split 2009 N-XYTER PCB requirements for FEB_D Raised bondpad pitch Separated LVDS and common mode signals NXYTER chip and PCB hardware with efficient and regulated cooling Additional diagnostic hardware Power control

14 th CBM Collaboration Meeting Split 2009 N-XYTER PCB Cooling Plate Cooling Block for FEB_B, FEB_C and FEB_D Design and Picture by Carmen Simons

14 th CBM Collaboration Meeting Split 2009 FEB_D N-XYTER Cooling A copper plate will be fixed on the bottom PCB side The N-XYTER will be placed on this copper plate from top side

14 th CBM Collaboration Meeting Split 2009 N-XYTER FEB_D PCB Changed/added: Alternative connector for separated LVDs and common mode signals New bond pitch Separated supply regulators 0.3V LDOs used PT100 sensor out Testpoints New power connector I2C and SPI spike filter I2C reads now: Temperature Current Testchannels Slow, Fast I2C RW: Serial EEprom for data storage

14 th CBM Collaboration Meeting Split 2009 Status Power supply tests will continue with new design FEB_D PCB is now ordered FEB_D assembly is open New cooling case design ready for FEB_B, FEB_C and FEB_D

14 th CBM Collaboration Meeting Split 2009 Thanks for your attention