MONSOON IR Acquisition Aladdin Front End

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MONSOON IR AcquisitionAladdin Front End
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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
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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

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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.

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MONSOON IR AcquisitionOrion Front End
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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
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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

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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

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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.

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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 Orions 1.5 msec pixel time _at_ 10 fps.
• Histograms become jagged at higher input levels.
• Unable to fit recommended Vref capacitor (47 mF)
  for AD7671 on board.