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Published byCarmel Houston Modified over 9 years ago
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1 Design Review Slow Control Part Hervé MATHEZ IPNL CNRS SLOW CONTROL PART IN FPPA 2000/2001
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2 Design Review Slow Control Part Hervé MATHEZ IPNL CNRS LEAKAGE CURRENT SPECIFICATIONS Input : 20nA to 20µA for twin APD Leakage current return to ground (only FPPA gnd point) No schematic changes between FPPA2000 and FPPA2001 APD anode voltage must be stabilized at ± 25 mV (Rp, HV) Minimum leakage current to be measured ± 200 nA (Il(T), T) Non linearity over full scale is 1% Low input bias current amplifier Output 0.5 V to 2.5V compatible with FPU input
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3 Design Review Slow Control Part Hervé MATHEZ IPNL CNRS TEMPERATURE MEASUREMENT SPECIFICATIONS Range : 5°C to 25°C T to be measured : ± 0.1°C Current measurement through a thermistor (R 25°C = 100 k , = 3960 K) between 2 constant voltages (2.4V and 1.2V, self heating) Input current : 4.3 µA to 12 µA @ 18°C, 0.1°C is 40 nA Constant voltage must stabilized at ±5 mV Non linearity : 0.3% Output 0.5 V to 2.5V compatible with FPU input No schematic changes between FPPA2000 and FPPA2001
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4 Design Review Slow Control Part Hervé MATHEZ IPNL CNRS + - + - C*V ref ADC + - HV APD RfRf RpRp V out (I Leakage ) ADC Output = f (V refADC,R f ) External components OTA2 Open loop gain 90dB, Fc< 1kHz, with output capacitor of 5pF Phase margin 80° (Also used in temperature measurement) OTA1 is modified in order to Vanode APD goes to 0V Open loop gain 65dB, Fc< 20kHz, with output capacitor of 5pF Phase margin 80° HOW TO DO LEAKAGE CURRENT MEASUREMENT ? OTA1 OTA2
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5 Design Review Slow Control Part Hervé MATHEZ IPNL CNRS C*V ref ADC + - V out (dummy) RfRf RfRf C*V ref ADC - - B*V ref ADC + - + - + + A*V ref ADC + - + - R off R(T) R dummy V CC V out (T) A*V ref ADC ADC Output = f (R(T),R off,R f ) External components All same OTA have input bias current compensated HOW TO DO TEMPERATURE MEASUREMENT ?
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6 Design Review Slow Control Part Hervé MATHEZ IPNL CNRS OTA FOR BOTH MEASUREMENTS OTA 1 OTA 2 GdB=90 dB Phase Margin=80° GdB=65 dB Phase Margin=80°
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7 Design Review Slow Control Part Hervé MATHEZ IPNL CNRS LEAKAGE CURRENT MONTE CARLO ANALYSIS (FPPA2000) 0.5 V < Vout < 2.5 V < 1 %
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8 Design Review Slow Control Part Hervé MATHEZ IPNL CNRS LEAKAGE CURRENT MONTE CARLO ANALYSIS (FPPA2000) V anode APD 1.4 mV
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9 Design Review Slow Control Part Hervé MATHEZ IPNL CNRS LEAKAGE CURRENT MONTE CARLO ANALYSIS (FPPA2000) Input Bias Current < 50 nA (except for 5 MC run) Very low variation versus input current
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10 Design Review Slow Control Part Hervé MATHEZ IPNL CNRS TEMPERATURE MEASUREMENT MONTE CARLO ANALYSIS (FPPA2000) 0.5 V < Vout < 2.5 V << 0.1 %
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11 Design Review Slow Control Part Hervé MATHEZ IPNL CNRS TEMPERATURE MEASUREMENT MONTE CARLO ANALYSIS (FPPA2000) 1.2 V Voltage variation across R(T) over the full range Offset current for 50 MC run
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12 Design Review Slow Control Part Hervé MATHEZ IPNL CNRS SUMMURAY OF MONTE CARLO ANALYSIS (FPPA2000) Temperature Input Current Leakage Input Current Additional BJT to provide high reverse voltage Base-Emitter noticed by MC simulations All other simulations (transient) are correct Offset Current Ouput Voltage reference
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13 Design Review Slow Control Part Hervé MATHEZ IPNL CNRS CONCLUSION (FPPA2000) SLOW CONTROL PART WORKS WELL AND ALL MEASUREMENTS ARE IN SPECIFICATION
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