Transcript Dec 2003 - Project Status Review IR SYSTEMS

MONSOON IR Acquisition
Aladdin Front End
2.500 V REF
4.7 uF
Aladdin Front End Test Results
Counts
Channel #
ADU
• 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
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.
MONSOON IR Acquisition
Orion Front End
2.500 V REF
4.7 uF
Orion Front End Test Results
Counts
Channel #
ADU
• 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
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 Acquisition
Current 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.