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2.500 V REF. 4.7 uF. MONSOON IR Acquisition Aladdin Front End. Aladdin Front End Test Results. 1 k W external load, BW = 7 MHz No filtering/bypassing of OFFSET ADC input adjusted with OFFSET to low level Histogram means are normalized to 50 ADU Ave. mean = 7,498 ADU
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2.500 V REF 4.7 uF MONSOON IR AcquisitionAladdin Front End
Aladdin Front End Test Results • 1 kW external load, BW = 7 MHz • No filtering/bypassing of OFFSET • ADC input adjusted with OFFSET to low level • Histogram means are normalized to 50 ADU • Ave. mean = 7,498 ADU • Ave. s.d. = 2.37 ADU Counts Channel # ADU
Aladdin Front End Test Results • 1 kW external load, BW = 7 MHz • No filtering/bypassing of OFFSET • ADC input adjusted with OFFSET to high level • Histogram mean is normalized to 50 • Ave. mean = 59,566 ADU • Ave. s.d. = 2.36 ADU • Histograms less smooth at high input level
Aladdin To Orion Front End Changes • 100 kW internal load resistor increased to 10 MW • Bipolar input AD8021 op amp replaced with FET input OPA627 • Large 2.2 mF bypass capacitor placed on incoming OFFSET • Gain reduced from 3.0 to 2.5 • BW reduced from 7 MHz to 3 MHz.
2.500 V REF 4.7 uF MONSOON IR AcquisitionOrion Front End
Orion Front End Test Results • 1 kW external load, BW = 6 MHz • OFFSET bypassed with 2.2 mF. • ADC input adjusted with OFFSET to low level • Histogram mean is normalized to 50 • Ave. mean = 7,501 ADU • Ave. s.d. = 1.68 ADU Counts Channel # ADU
Orion Front End Test Results • 1 kW external load , BW = 3 MHz • OFFSET bypassed with 2.2 mF. • ADC input adjusted with OFFSET to high level • Histogram mean is normalized to 50 • Ave. mean = 57,810 ADU • Ave. s.d. = 1.72 ADU • Smoother at high level input than Aladdin
MONSOON IR AcquisitionCurrent Tests • ADC input voltage vs. Offset code • Histograms of 1 kW input load to ground for low/high level offset. • Histograms of D.C. input for low/high levels • Histograms of dynamic step input on even/odd channels • Sinewave input to get frequency spectrum • Sinewave input to get DNL, and maximum INL
Orion Test System • 1 IR Acquisition mother and daughter board in test. • 1 IR Acquisition mother and daughter board nearly complete pending test results of first board. • 1 Clock and Bias board 80 % done. • Chassis and CPCI backplane integrated. • Power supplies on hand.
MONSOON IR Acquisition Conclusions/Concerns • About 1.7 ADU noise performance with Orion design for static 1kW source. • Orion design BW = 3 MHz greater than necessary for Orion’s 1.5 msec pixel time @ 10 fps. • Histograms become jagged at higher input levels. • Unable to fit recommended Vref capacitor (47 mF) for AD7671 on board.