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Liverpool Status. Since last time Power Protection Replacement Board done Check if it recovers DTnoise Quick submission – proof of principle Provides for serial powering of modules (not hybrids) Simple drop-in replacement for existing PPBs 93.5mm x 5mm Received in RAL this week
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Liverpool Status • Since last time • Power Protection Replacement Board done • Check if it recovers DTnoise • Quick submission – proof of principle • Provides for serial powering of modules (not hybrids) • Simple drop-in replacement for existing PPBs • 93.5mm x 5mm • Received in RAL this week • Module/Hybrid Twiki being set up: https://twiki.cern.ch/twiki/bin/viewauth/Atlas/ShortStripsHybridLiverpool • Provides information regarding hybrids – layout files (gerbers), BOM, schematics, etc. • Module frames and their connections (Power, data I/O, …) • Miscellaneous information (LVDS buffer board) • Hooking up to HSIO • Updated regularly... • 2 Modules delivered to RAL last week • For DCDC stavelet • Made with FZ2 sensors (Modules: M13 & M15) • 2 more modules, M16 & M17 (nearly) ready in Liverpool (see later), again made with FZ2 sensors • M16 now tested ok, M17 to be tested soon • 1 module, M14, made with FZ1 sensor. Retain as spare • HSIO now hooked up to hybrid(s) for readout • Identified problem with DCLK – BCO timing, modification of start up script solved the problem • Using CLKmode80 set to logic 1 (simple wire bond change on hybrid) • Now testing with 80MHz DCLK (as presently used on Stavelets) and not 40MHz • L1Delay in the hybrid configuration revised to 129 (was 132 due to BCC latency) – otherwise calibration out of time
Liverpool Status • Continued... • Started preparing 2 outstanding modules for DCDC stavelet • Initially identified a problem with a single BCCV2 on module M16 (non working DCLK) • Replaced early this week (BCC courtesy of RAL) • Full electrical test performed (3pt Gain, Trim, etc.) • Minor issue identified with low gain on 2 ABCN25s (≥100mV/fCinstead of 110mV/fC) – DAQ issue • Revisited module but unable to readout – identified problem with a BCC • Same BCC location as before - non working DCLK (again) • Further investigation revealed hybrid voltage not being regulated properly • Starts up ok with hybrid voltage at 2.52V (at power entry of hybrid) • Revisit a bit later now measuring >2.8V • Problem identified with Mshunt control circuit – one end of resistor not soldered • Open circuit connection forces control circuit to (erroneously) over compensate hybrid voltage • Reflowing solder joint fixes the problem – circuit now regulates properly and module fully functioning • Recommendation gone out that all sites, with hybrids, visually inspect Mshunt circuit for quality of soldering