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Noise in the irradiated FE-I4-B versus temperature. A.Rozanov , F.Bompard (CPPM). Outlook. Conditions Digital tests Analog test P roblem with f reezing FE-I4 output. Conditions. Single board FE-I4-B sn 165 in lab 892-S-D19
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Noise in the irradiated FE-I4-B versus temperature A.Rozanov, F.Bompard (CPPM) A.Rozanov FE-I4 tests 29.07.2013
Outlook • Conditions • Digital tests • Analog test • Problem with freezing FE-I4 output A.Rozanov FE-I4 tests 29.07.2013
Conditions • Single board FE-I4-B sn 165 in lab 892-S-D19 • Irradiated in 2012 at CERN PS with 24 GeV protons close to the region of end of columns at 400 MRads • Chip configuration: FEI4b.irradiated.chip.165.tuned.3000e.TOT8.cfg.root from 17.04.2013 (tuning made by Maurice Garcia) • USBpix board with grey flat cable to single chip board • Typical consumption: Vdda=2.5v Idda=430 mA, Vdd=2.5v Iddd=181 mA on external power supply • STControl version in MARNACHE from directory release-3.3/bin/STcontrol.exe from 08.03.2013 • Temperature regulated inside the freezer FARK 3130A with dry air flow • Noise measured with NoiseOccscan usually with 10**5 pixel headers. A.Rozanov FE-I4 tests 29.07.2013
Setup A.Rozanov FE-I4 tests 29.07.2013
Digital Test • Digital_Test good for nominal configuration parameters: Amp2Vbpf=100 A.Rozanov FE-I4 tests 29.07.2013
Digital Test • Very High noise at small value of Amp2Vbpf=5 block the discriminator, so the 400 MRadbeam spot is clearly seen. A.Rozanov FE-I4 tests 29.07.2013
Digital Test • At intermediate values of Amp2Vbpf=10,20,40 the 400 MRadbeam spot also seen. Amp2Vbpf=40 Amp2Vbpf=10 Amp2Vbpf=20 A.Rozanov FE-I4 tests 29.07.2013
NoiseOcc test • Typical statistics 10**5 headers • No noise at room temperature at nominal settings • Some noise at low temperature t=-22 degC, partly correlated with Beam Spot • In this test 1944 hits/10**5 headers • Noise only in 5 pixels A.Rozanov FE-I4 tests 29.07.2013
NoiseOcc test • For low value of Amp2Vbpf=20 strong noise at low temperature t=-22 degC, strongly correlated with Beam Spot • In this test 46746 hits/10**5 headers A.Rozanov FE-I4 tests 29.07.2013
NoiseOcc test • For intermediate value of Amp2Vbpf=40 noise at low temperature t=-22 degC, strongly correlated with Beam Spot • In this test 23676 hits/10**5 headers A.Rozanov FE-I4 tests 29.07.2013
Noise versus temperature • For nominal value of Amp2Vbpf=100 noise starts at t~-10 degC • Typical 500/4000 hits/10**5 headers A.Rozanov FE-I4 tests 29.07.2013
Noise versus temperature • For Amp2Vbpf=200 noise is similar to Amp2Vbpf=200 • Typical 200/5000 hits/10**5 headers A.Rozanov FE-I4 tests 29.07.2013
Noise versus temperature • For Amp2Vbpf=20 or 40 noise linearly increase at low temperatures A.Rozanov FE-I4 tests 29.07.2013
FE-I4-B output stuck by lowering temperature • Remarked that by lowering the temperature FE-I4 is often stuck with no data coming out • Happens with both DIGITAL_TEST and NoiseOcc. Even in the middle of the run • Does not happens increasing the temperature … • Reconfigure module does not help, but OFF/ON power cycle by STControl interface help • Malte told me that similar problem was observed in IBL modules and HardReset help to restart the module • In our case HardReset also helps A.Rozanov FE-I4 tests 29.07.2013
Conclusions • Below t=-10 degC noise increase at nominal setting in few pixels • Partly correlated with irradiated region of the chip • At low values of Amp2Vbpf linear increase of the noise lowering the temperature • Strange effect of FE-I4 output stuck by lowering the temperature. Does it need more detailed investigations ? • More details in E-log: https://atlpix01.cern.ch/elog/FE-I4_SEU_measurements/302 A.Rozanov FE-I4 tests 29.07.2013
Spare A.Rozanov FE-I4 tests 29.07.2013
Some parameters of the configuration • FEI4b.irradiated.chip165.tuned3000e.TOT8.cfg.root • Amp2Vbn=79 • Amp2Vbp=85 • Amp2Vbpfol=26 • Amp2Vbpf=100 • Vthin_AltCoarse=0 • Vthin_AltFine=140 • FdacVbn=20 • DisVbn=26 A.Rozanov FE-I4 tests 29.07.2013