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Welcome. System Test Measurements with Pixel Modules and DC-DC Converters Phase I Pixel Upgrade Workshop Grindelwald , August 2012 Lutz Feld , Waclaw Karpinski , Katja Klein, Jan Sammet , Michael Wlochal. Welcome. Contents. DC-DC Converters for the Phase I Pixel Upgrade
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Welcome System Test Measurements with Pixel Modules and DC-DC Converters Phase I Pixel Upgrade Workshop Grindelwald, August 2012 Lutz Feld, WaclawKarpinski, Katja Klein,Jan Sammet, Michael Wlochal
Welcome Contents • DC-DC Converters for the Phase I Pixel Upgrade • Set-up for System Tests • New Results from System Test Measurements • A feature of previous measurements • Tests with one pair of AMIS2/AMIS4 converters and one pixel module • Tests with four pairs of AMIS4 converters and two pixel modules • Front-end vs. back-end sensing • Occupancy tests with low thresholds • Thermal Cycling of DC-DC Converters – First Results • Summary and Outlook Jan Sammet
Welcome Aachen AMIS4 DC-DC Converters AC_PIX_V8 A 2.8cm x 1.6cm; ~ 2.0g • 4 variants with AMIS4 produced • Version A layout very similar to AMIS2_PIX_V7 • C, D, E: lower mass, smaller ( phase-2) • ASIC: AMIS4 by CERN • Vout: 3.3V and 2.5V • fs = 1.5MHz • Toroidalplasticcoreinductorwith L = 450nH • Pi-filtersat in- andoutput V8 C: small caps 2.8cm x 1.6cm; 1.6-1.7g V8 D: 1.5mm shorter 2.65cm x 1.6cm, ~ 1.6g V8 E: 1mm smallest 2.6cm x 1.5cm; 1.5-1.6g Jan Sammet
Welcome Implementation into CMS • Installation onto supply tube • 24 to 26 DC-DC converters mounted on converter bus board • In total 32 converter bus boards DC-DC converters Pixel detector Bus board with 24 DC-DC converters (w/o shieldings) Jan Sammet
Welcome Tests with 2 Modules and 8 Converters (AMIS2) • System tests based on module qualification set-up • Operated with up to two modules and 8 DC-DC converters • Perform threshold scans and compare s-curve noise with and without DC-DC converters Modules Dynamic digital load I (t) DC-DC converters Const. analogue load Module Module Moduleadapter Moduleadapter 0.17 Connector board Connector board 0.35 CAEN Pixel PS VD VD readout readout SY1527 + Branch Controller EASY 4000 PSM A4603 VD VD 8 DC-DCconverters on common bus board VA VA Long power cables (40m) VA VA HV (150V) Jan Sammet
Welcome Previous Measurements • Hardware configuration: • One pixel module • One pair of AMIS2_V7 / equivalent CAEN PS • Front-end sensing • Results: • Reproduction of previous results • Unintended feature of previous measurements: • Vana is set by measuring analogue current on TB; not in ROC • PreTest sets voltage of analogue regulator on ROC to maximum (Vana = 255) • Larger current through preamplifier reduces sensitivity to intrinsic noise • Small dropout of regulator increases sensitivity to external noise (e.g. orbit gaps) • Measurement under unrealistic conditions Jan Sammet
Welcome New Tests with AMIS2_V7 (S-Curve Noise) • Results: • Reproducibility of identical measurements:0.5e- • Average noise approximately 5e- (3.2%) higher than with Testboard • Almost no difference between CAEN and DC-DC converters • CAEN slightly more sensitive to orbit gaps (noise increased 1e- 0.6%) • Hardware configuration: • Single module • One pair of AMIS2_V7 vs. equivalent CAEN • Front-end sensing • Software configuration: • Trimmed threshold = 60 Vcal DACs • Use Vana and all other parameters from configuration with testboard Jan Sammet
Welcome New Tests with AMIS2_V7 (Threshold) • Results: • Reproducibility of identical measurements:75e- • No significant differences • Hardware configuration: • Single module • One pair of AMIS2_V7 vs. equivalent CAEN • Front-end sensing • Software configuration: • Trimmed threshold = 60 Vcal DACs • Use Vana and all other parameters from configuration with testboard Jan Sammet
Welcome Tests with AMIS4_V8A (S-Curve Noise) • Results: • Noise with AMIS4 slightly lower (1e- / 0.6%) than with AMIS2 • With AMIS4 and (inv.) orbit gaps, no significant increase in noise • With CAEN and const. load no significant increase in noise • With CAEN and (inv.) orbit gaps, noise increases by ~ 1e- (0.6%) • Hardware configuration: • Single module • One pair of AMIS4_V8A / equivalent CAEN • Front-end sensing • Software configuration: • Trimmed threshold = 60 Vcal DACs • Use Vana and all other parameters from configuration with testboard Jan Sammet
Welcome Tests with 8 x AMIS4 (S-Curve Noise) • Results: • With CAEN PS and orbit gaps, noise increases by 36% • With CAEN PS and inv. orbit gaps, noise increases by 10% • No significant increase with constant load • No significant increase with DC-DC converters • Hardware configuration: • Four pairs of AMIS4_V8A / equivalent CAEN • Two modules powered by one converter pair • Plots are from M806 • Front-end sensing • Software configuration: • Trimmed threshold = 60 Vcal DACs • Use Vana and all other parameters from configuration with testboard Jan Sammet
Welcome Tests with 8 x AMIS4 (S-Curve Noise) • Hardware configuration: • Four pairs of AMIS4_V8A vs. equivalent CAEN • Two modules powered by oneconverter pair • Plots are from M1176 • Front-end sensing • Results: • With CAEN PS and orbit gaps, noise increases by 19% • With CAEN PS and inv. orbit gaps, noise increases by 15% • No significant increase with constant load • No significant increase with DC-DC converters • Software configuration: • Trimmed threshold = 60 Vcal DACs • Use Vana and all other parameters from configuration with testboard Jan Sammet
Welcome VA and VD at the Module -2V offset -2V offset -2V offset -2.5V offset -3V offset -3V offset -2V offset -2.8V offset No add load 2A No add load 2A -2V offset Orbit gaps Inv OG -2V offset -2V offset -2V offset -2.8V offset -2.8V offset Orbit gaps Inv OG -2.75V offset -2.65V offset CAEN DC/DC • Hardware configuration: • Four pairs of AMIS4_V8A / equivalent CAEN • Two modules on same converter pair • Observation: • DC-DC converters reduce oscillations • With DC-DC converters VA is hardly affected by load variations on VD • Oscilloscope settings: • VA: 100mV and 20µs per division • VD: 100mV and 20µs per division Jan Sammet
Welcome Tests with 8 x AMIS4 (Threshold) • Hardware configuration: • Four pairs of AMIS4_V8A / equivalent CAEN • Two modules powered by one converter pair • Plots are from M806 • Front-end sensing • Results: • No significant differences • Software configuration: • Trimmed threshold = 60 Vcal DACs • Use Vana and all other parameters from configuration with testboard Jan Sammet
Welcome Tests with Low Threshold / High Occupancy with testboard with CAEN with DCDC • Hardware configuration: • Four pairs of AMIS4_V8A / equivalent CAEN • Two modules powered by one converter pair • Back-end sensing • Plots are from M806 • Results: • Highest noise with TB, lowest with AMIS4: • CAEN to DCDC: +1.6e- = 0.6% • Testboard to DCDC: +5.7e- = 2.3% • Lowest threshold with TB, highest with CAEN • CAEN to DCDC: + 3.7e- (0.3%) • Testboard to DCDC: - 32.9e- (2.3%) • Number of dead/busy pixels similar in all cases • Software configuration: • Trimmed to low threshold (10 Vcal DACs) • Inefficiencies Jan Sammet
Welcome First Results with Thermally Cycled Converters • Eight converters cycled successfully • Load during cycling: 25 W • In ~10h: 3 x +20°C ... -40°C 10 x +20°C ... -20°C 2 x +20°C ... -10°C 50min @ 0°C • No defects, no problems, no effect on system tests • System tests with converters @ 0°C show no abnormality Jan Sammet
Welcome System Tests after Thermal Cycling TDCDC = 20°C TDCDC = 0°C • Hardware configuration: • Four pairs of AMIS4_V8A • Two modules powered by one converter pair • Plots are from M806 • Results: • No problems observed after thermal cycling • Software configuration: • Trimmed threshold = 60 Vcal DACs • Use Vana and all other parameters from configuration with testboard Jan Sammet
Welcome System Tests after Thermal Cycling TDCDC = 20°C TDCDC = 0°C • Hardware configuration: • Four pairs of AMIS4_V8A • Two modules powered by one converter pair • Plots are from M1176 • Results: • No problems observed after thermal cycling • Software configuration: • Trimmed threshold = 60 Vcal DACs • Use Vana and all other parameters from configuration with testboard Jan Sammet
Welcome Summary and Outlook • Summary • New measurements performed with more reasonable configuration • In all tests AMIS4 DC-DC converters did not cause any additional noise or performance degeneration • AMIS4 converters reduce the impact of fast load variations • We did not encounter any problems operating AMIS4 converters with front-end or back-end sensing of the CAEN PS • After thermal cycling eight converters, none has shown any abnormality • Outlook • Perform measurements with full bus board • Improve monitoring features of cycling software Jan Sammet
Welcome Back-Up Slides Jan Sammet
Welcome Aachen DC-DC Converter “PIX_V7“: ASIC: AMIS2 by CERN Iout < 3A Vin < 12V Vout configurable; 2.5V & 3.3V fs configurable, e.g. 1.3MHz PCB:2 copper layers a 35µm 0.3mm thick Large ground area on bottom for cooling Toroidal inductor: L = 450nH RDC = 40m Pi-filters at in- and output A = 28 x 16 mm2 M 2.5g 3.8% of a radiation length Shield/heat sink Design guidelinesfrom CERN group havebeenimplemented. Jan Sammet
Welcome AMIS4 ASIC Features: • Bandgapand 4 linear regulatorsintegrated • Dead time handlingwith adaptive logic • Triplicationandlogicagainst SEU • Improved power transistor design wrt TID • Over-currentprotection • Over-temperatureprotection • Input under-voltageprotection • State machinefor soft start-upprocedure,handlingofprotectionsignalsandgenerationof “power good“ signal Operating parameters: • Vin < 10V • Iout < 3A (4A @ -30°C) • fs = 1-3MHz • L = 200-500nH Received chips: • 20 bare chips, bonded and packaged in Aachen • 40 chips, packaged by Europractice Jan Sammet
Welcome Reproducibility of Measurements • Standard deviation of individual measurements: ~21e- • Standard error of the means of individual measurements : ~0.08e- • Standard deviation of the mean of four identical measurements: 0.38e- • Fluctuation due to temperature changes (of the coolant): 0.36e-/°C • Guestimate: expected fluctuations < 0.38e- 0.36e- 0.5e- • N(T) = T (0.36 ± 0,02) [e-] • ± 1°C ± 0.36e- [e] [°C] Jan Sammet
Welcome CAEN vs. 2 x AMIS2_V7 • Hardware configuration: • Single module • One pair of AMIS2_V7 vs. equivalent CAEN • Back-end sensing • Results: • With CAEN PS and orbit gaps, noise increases by 23% (75) • With CAEN PS and inv. orbit gaps, noise increases by ~3 • No significant increase with constant load • No significant increase with DC-DC converters • Software configuration: • Trimmed threshold = 60 Vcal DACs • Use Vana and all other parameters from configuration with testboard Jan Sammet
Welcome CAEN vs. AMIS4_V8A • Hardware configuration: • Single module • One pair of AMIS4_V8A vs. equivalent CAEN • Back-end sensing • Results: • With CAEN PS and orbit gaps, noise increases by 23% (75) • With CAEN PS and inv. orbit gaps, noise increases by ~3 • No significant increase with constant load • No significant increase with DC-DC converters • Same results as with AMIS2_V7 • Software configuration: • Trimmed threshold = 60 Vcal DACs • Use Vana and all other parameters from configuration with testboard Jan Sammet
Welcome Tests with 8 x AMIS4 (S-Curve Noise) • Hardware configuration: • Four pairs of AMIS4_V8A / equivalent CAEN • Two modules powered by two converter pairs • Front-end sensing • Plots are from M806 • Results: • With CAEN PS and orbit gaps, noise increases by 36% • With CAEN PS and inv. orbit gaps, noise increases by 10% • No significant increase with constant load • No significant increase with DC-DC converters • Software configuration: • Trimmed threshold = 60 Vcal DACs • Use Vana and all other parameters from configuration with testboard Jan Sammet
Welcome Tests with 8 x AMIS4 (S-Curve Noise) • Hardware configuration: • Four pair of AMIS4_V8A vs. equivalent CAEN • Two modules powered by two converter pairs • Plots are from M1176 • Front-end sensing • Results: • With CAEN PS and orbit gaps, noise increases by 19% • With CAEN PS and inv. orbit gaps, noise increases by 15% • No significant increase with constant load • No significant increase with DC-DC converters • Software configuration: • Trimmed threshold = 60 Vcal DACs • Use Vana and all other parameters from configuration with testboard Jan Sammet
Welcome CAEN vs. 8 x AMIS4_V8A (M806) • Hardware configuration: • Four pairs of AMIS4_V8A vs. equivalent CAEN • Two modules powered by two converter pairs • Plots are from M806 • Back-end sensing • CAEN measurements with front-end sensing (back-end sensing with CAEN only and large load variations is not feasible) • Results: • No significant increase with constant load • No significant increase with DC-DC converters • Software configuration: • Trimmed threshold = 60 Vcal DACs • Use Vana and all other parameters from configuration with testboard Jan Sammet
Welcome CAEN vs. 8 x AMIS4_V8A (M1176) • Hardware configuration: • Four pairs of AMIS4_V8A vs. equivalent CAEN • Two modules powered by twoconverter pairs • Plots are from M1176 • Back-end sensing • CAEN measurements with front-end sensing (back-end sensing with CAEN only and large load variations is not feasible) • Results: • No significant increase with constant load • No significant increase with DC-DC converters • Software configuration: • Trimmed threshold = 60 Vcal DACs • Use Vana and all other parameters from configuration with testboard Jan Sammet
Welcome 2 x AMIS4 vs. CAEN, Front-End Sensing -3V -3V -2.8V -2.8V -3V -3V -2.8V -2.8V CAEN DC/DC • Hardware configuration: • Single module • One pair of AMIS4_V8A vs. equivalent CAEN • Front-end sensing • System tests: small increase (<1% / ~2) in noise with CAEN and (inv.) orbit gaps • Observation: • Larger oscillations with CAEN • In particular also on VA Jan Sammet
Welcome 2 x AMIS4 vs. CAEN, Back-End Sensing -3V -3V -3V -3V -2.8V -3V -3V -3V CAEN DC/DC • Hardware configuration: • Single module • One pair of AMIS4_V8A vs. equivalent CAEN • Back-end sensing • System tests: smallish increase (~1% / ~3 ) in noise with CAEN and inv. orbit gaps significant increase (23% / ~75 ) in noise with CAEN and orbit gaps • Observation: • Larger oscillations with CAEN • With CAEN PS, oscillations on VA larger than with front-end sensing • However: small difference between iOG & OG Jan Sammet
Welcome 2 x CAEN , Front-End Sensing No add load 2A Orbit gaps Inv OG Jan Sammet
Welcome 2 x CAEN, Back-End Sensing No add load 2A Orbit gaps Inv OG Jan Sammet
Welcome 2 x AMIS4, Front-End Sensing No add load 2A Orbit gaps Inv OG Jan Sammet
Welcome 2 x AMIS4, Back-End Sensing No add load 2A Orbit gaps Inv OG Jan Sammet
Welcome Module Defects • Four not understood module failures (broken TBMs) within four months • Investigated/excluded several possible explanations • In particular ESD and DC-DC converters very unlikely to be the cause • Most likely: EMI of adjacent set-up, when AC connectors (230V) are (dis)connected • Many thanks to W.Erdmann and S.Streuli from PSI for their help! Set-up adjacent to pixel modules Jan Sammet
Welcome Tests with Low Threshold / High Occupancy with testboard with CAEN with DCDC • Hardware configuration: • Four pairs of AMIS4_V8A / equivalent CAEN • Two modules powered by one converter pair • Back-end sensing • Plots are from M806 • Results: • Most dead pixels with Testboard, least with CAEN • CAEN – Testboard = 108.7 • DCDC – Testboard = 93.02 • CAEN – Testboard = 15.68 • No performance degradation due to DC-DC converters observable • Software configuration: • Trimmed to low threshold (10 Vcal DACs) • Inefficiencies Jan Sammet