Future Developments of Infrared Controllers at ESOFuture Developments of Infrared Controllers at ESO...
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Future Developments of Infrared Controllers at ESO Gert Finger
Transcript of Future Developments of Infrared Controllers at ESOFuture Developments of Infrared Controllers at ESO...
Future Developments ofInfrared Controllers at ESO
Gert Finger
Next Generation IR Detectors
Detector Format Outputs Pixel Time Frame Time Baud Rate[µs] [ms] Gbaud
Hawaii-2RG MBE HgCdTe 2Kx2K 32 0.2 26 2.6Si:As BIB 640x480 32 0.3 2.8 1.7ORION 2Kx2K InSb 2Kx2K 64 1.5 100 0.7Adaptive optics sensors 256x256 32 0.2 0.41 2.6
l need 5 MHz 16 bit ADC’sl need 3 Gbaud fiber link
Future Requirements forIRACE
l Large format mosaics of 4x4x2Kx2K IR arrayseach having >= 32 parallel video outputs (VISTA)
l Subpixel sampling by digital filter in EPLDl Reference unit cells for true differential signal chainl Interpolated digital clamp of reference unit celll Embedded real time pre-processing in high level
programming language such as IDL ( cosmic ray rejection)l Guiding on science framel diagnostics , self test of acquisition system, on line helpl Audio DAC’s to control clock slopes ?l Put detector front end in ASIC close to focal plane
Large Format : VISTA
IR imager
1.2°
1.67°
l 4 meter telescope, field 1.67 degl mosaics of 4x4x2Kx2K IR arrays
bench
Slide provided byMark Casali / UKATC
l eight filter units, eachcontaining sixteen filters,each 54mm square
l with HAWAII2 mux usefour quadrants fortracking,guiding andwave-front sensing
l with HAWAII2-RG useguiding feature built intodetector
Large Format: VISTA
Slide provided byMark Casali / UKATC
IR imagerfocal plane module
16 detectors
2 boards and 2 external connectorsper detector
thermal bus bars [4]
base plate
housing
Integrate cryo-opamps and filters in flex board
VISTA focal plane
l 16 2Kx2K arrayseach having 32parallel outputs
l 512 channelIRACE system
l readout time 1.3 s
Slide provided byMark Casali / UKATC
Digital filter in EPLD of AQ1616-Bit
16-Bit
ADC withoutput register 16-Bit
ADC withoutput register 16-Bit
ADC withoutput register 16-Bit
ADC withoutput register 16-Bit
ADC withoutput register 16-Bit
ADC withoutput register 16-Bit
ADC withoutput register 16-Bit
ADC withoutput register 16-Bit
16-Bit
16-Bit
16-Bit
16-Bit
16-Bit
16-Bit
16-Bit
16-Bit
Ana
log
inpu
t sig
nal
Ana
log
inpu
t sig
nal
Ana
log
inpu
t sig
nal
Ana
log
inpu
t sig
nal
Ana
log
inpu
t sig
nal
Ana
log
inpu
t sig
nal
Ana
log
inpu
t sig
nal
Ana
log
inpu
t sig
nal
ADC withoutput register 16-Bit
ADC withoutput register 16-Bit
ADC withoutput register 16-Bit
ADC withoutput register 16-Bit
ADC withoutput register 16-Bit
ADC withoutput register 16-Bit
16-Bit
16-Bit
16-Bit
16-Bit
16-Bit
16-Bit
16-Bit
16-Bit
Ana
log
inpu
t sig
nal
Ana
log
inpu
t sig
nal
Ana
log
inpu
t sig
nal
Ana
log
inpu
t sig
nal
Ana
log
inpu
t sig
nal
Ana
log
inpu
t sig
nal
Ana
log
inpu
t sig
nal
Ana
log
inpu
t sig
nal
16
-B
it b
us
(lo
w w
or
d o
f 3
2-
Bi
t b
us
)
16
-B
it b
us
(h
igh
wo
rd
of
32
-B
it b
us
)
Output register 16-Bit
Dsu
b 37
-pin
s co
nnec
tor
only
ana
log
sign
als
Mon
itorin
g of
ana
log
inpu
t sig
nals
Amplifier & analog multiplexer
EPLDcontrol unit
ADC withoutput register 16-Bit
ADC withoutput register 16-Bit
Off
set e
limin
atio
ns
of a
nalo
g in
put s
igna
l
P2 b
ackp
lane
con
nect
orD
ata
I/O b
us (G
iga
bus)
Output register 16-Bit
VMEInterface
P1 b
ackp
lane
con
nect
orV
ME
inte
rfac
e
l process subpixel samplesin EPLD
l parallel processing1 processor /AQ board
l digital filter of video signal
Conversionstrobes
Video signal
AQ 16 board
Reference unit cell (Hawaii2)l 8 video outputs / quadrantl 128 pixels in fast directionl reference pixel for thermal
drift is 129 th pixel on 9 th outputl 36 channels / detector required
Video and Reference Signal of Hawaii 2 at end of Row
0.00
1.00
2.00
3.00
4.00
5.00
1.48E-03 1.50E-03 1.52E-03 1.54E-03 1.56E-03 1.58E-03 1.60E-03
Time [s]
Sig
nal
[V] Video
Reference
CLK1
External reference with Hawaii1l No reference output
provided on chipl external reference has to
be used
Gain=1+2RF/RG
On chip reference cell of Hawaii2l reference pixel for
thermal drift compensationand suppression of pickupis 129 th pixel on 9 th output
l reference pixel notavailable while readingpixels
l clock first to referencepixel
l clamp reference pixel withcryogenic sample and hold
l read pixels of row withclamped voltage atreference input of cryo-opamp
Gain=1+2RF/RG
On chip reference cell of Hawaii2-RGl reference pixel for
thermal drift compensationand suppression of pickupon 9 th output, but
l reference pixel availablewhile reading pixels
l read pixels of row withvoltage of reference cell atreference input ofcryo-opamp
l best suppression of noisepickup
Gain=1+2RF/RG
50 Hz pickup of Hawaii2without clamp of reference
l multiple sampling reduces readout noise andrequires lower pickup noise
l Clock each row once and read oncel reference output ( 129 th pixel on 9 th output ) is
not usedl 32 channels / detector required
Video and Reference Signal of Hawaii 2 at end of Row
0.00
1.00
2.00
3.00
4.00
5.00
1.48E-03 1.50E-03 1.52E-03 1.54E-03 1.56E-03 1.58E-03 1.60E-03
Time [s]
Sig
nal
[V] Video
Reference
CLK1
Video and Reference Signal of Hawaii 2 at end of Row
0.00
1.00
2.00
3.00
4.00
5.00
1.48E-03 1.50E-03 1.52E-03 1.54E-03 1.56E-03 1.58E-03 1.60E-03
Time [s]
Sig
nal
[V] Video
Reference
CLK1
Row n-1 Row n
ref n a ref n a
50 Hz pickup of Hawaii2 with digital clamp
l Clock each row once and read oncel read reference after reading row and and
subtract reference signal for each pixelsig nk =pix nk - refna
l 36 channels / detector required
Video and Reference Signal of Hawaii 2 at end of Row
0.00
1.00
2.00
3.00
4.00
5.00
1.48E-03 1.50E-03 1.52E-03 1.54E-03 1.56E-03 1.58E-03 1.60E-03
Time [s]
Sig
nal
[V] Video
Reference
CLK1
Video and Reference Signal of Hawaii 2 at end of Row
0.00
1.00
2.00
3.00
4.00
5.00
1.48E-03 1.50E-03 1.52E-03 1.54E-03 1.56E-03 1.58E-03 1.60E-03
Time [s]
Sig
nal
[V] Video
Reference
CLK1
Row n-1 Row n
ref n-1 a ref n a
50 Hz pickup of Hawaii2with interpolated digital clamp
l Clock each row twice and read oncel read reference before and after reading row and
interpolate reference signal for each pixelsig nk =pix nk - (ref nb - (ref nb -ref na)*(k-1)/127)
l 36 channels / detector requiredl reference allows rejection of low frequency
pickup and compensation of thermal drifts
Video and Reference Signal of Hawaii 2 at end of Row
0.00
1.00
2.00
3.00
4.00
5.00
1.48E-03 1.50E-03 1.52E-03 1.54E-03 1.56E-03 1.58E-03 1.60E-03
Time [s]
Sig
nal
[V] Video
Reference
CLK1
Video and Reference Signal of Hawaii 2 at end of Row
0.00
1.00
2.00
3.00
4.00
5.00
1.48E-03 1.50E-03 1.52E-03 1.54E-03 1.56E-03 1.58E-03 1.60E-03
Time [s]
Sig
nal
[V] Video
Reference
CLK1
Row n Row n
ref n b ref n a
Aladdin #3 & #4#4: QE H = 0.86 darkcurrent = 0.004 e/s
#5: QE H = 0.82 (ISAAC) darkcurrent = 0.017 e/s
Monitor temperature driftusing dead pixels
l Triangles:measuredintegration ramp
l Diamonds:dead pixels
l Open In bump bondsare used to monitordrifts
l Squares:drift correctedintegration ramp
l darkcurrentat 28.5 K:0.017 e/s/pixel
Temperature drift of deadpixels in Aladdin array
l Temperature drift:1700 electrons / K
l required temperaturestability of array:6 mK
l temperature drift willbe monitored withreference unit cell ofHawaii-2RG
Elimination of cosmic rays bymultiple sampling
Warm pixels continuous integration ramp
Cosmic rays create charge burstand step in integration ramp
Cosmic Ray Correction
l At Paranal (altitude 2600 m) 2038 pixels / hour are hit
l maximum charge injected by comic ray ~ 2E4 electrons < full well (1E5 electrons)
l correction by multiple nondestructivesampling and real time processing in IRACEnumber cruncher using idl routines
l at present more warm pixels than cosmics,but arrays may improve (MBE)
Parallel Processing of DetectorData in IRACE
l mark digitized videosignal with differentheaders
l process video signalin IRACE numbercruncher (ULTRA-SPARC) for scienceframe
l process subwindowin PowerPC on VMEbus for real timeapplications
Conclusion
l Mosaics of 2Kx2K arrays are comingl need 5 MHz 16 bit ADC’s and 3 Gbaud fiber linkl use of unit cell reference for true differential signal
chainl more real time image processing with faster
processorsl General purpose ASIC needed for ground based
applications
