Todd Moore for the DES CollaborationApril 20 th, 20071 Quick Summary of Noise Test Results. Noise...

Todd Moore for the DES Collaboration April 20th , 2007 1

• Quick Summary of Noise Test Results.• Noise test software & hardware setup.• Earth grounding/shielding scheme utilized for noise tests.

– Vicor supply with uRAM active filter ground/shield scheme.

– Vicor supply with voltage regulator ground/shield scheme.

• Test results.• Conclusion…

Vicor Power Supply Noise Test Results Ver. 9.0


Quick Summary ofNoise test Results

• All tests use FNAL focal plane (_fnal) with a readout rate of 6uS/Pixel.• Sigma count measurement could change by ~1.5 counts from day to

day, however counts would remain the same for the whole day of tests.

• Found another earth ground connected to signal ground on Vsub supply cable.

• Also received some information from Peter Moore explaining the wiring scheme he uses at CTIO.

– P. Moore’s information and finding the other earth ground reference required more testing to be done.

• Separate noise measurements were made when earth grounds were connected to supply grounds:

– at the backplane– at the Vicor power supply– at both backplane and power supply.

• Noise measurements were made with the above grounding schemes using the Vicor power supply with the +3.3V uRAM and with a +3.3V voltage regulator.



• Testing with uRAM:– Sigma was ~15.5 counts when

• +/-5, +/-15, and -28 analog voltage returns tied together at the power supply– & tied to power supply case (earth ground)

• +5 and +3.3 digital voltage returns tied together at the power supply– But not tied to power supply case (earth ground)

– Sigma was ~8 counts when ground scheme was based on P.Moore’s recommendation• +/-15 common returns tied together at the power supply• +/-5 common returns tied together at the power supply• +5VD, +3.3VD, & -28VA returns kept separate• Backplane tied to Monsoon chassis (earth ground)

– Sigma was ~7.7 counts when • +/-5, +/-15, and -28 analog voltage returns tied together at the power supply• +5 and +3.3 digital voltage returns tied together at the power supply• & backplane tied to Monsoon chassis (earth ground)

– Sigma was ~6.40 counts when • +/-5, +/-15, and -28 analog voltage returns tied together at the power supply

– & to power supply case (earth ground)• +5 and +3.3 digital voltage returns tied together at the power supply

– & to power supply case (earth ground)• Backplane ground tied to Monsoon chassis (earth ground)



• Testing with Voltage Regulator:– Sigma was ~13.5 counts when

• +/-5, +/-15, and -28 analog voltage returns tied together at the power supply– & tied to power supply case (earth ground)

• +5 digital voltage return not tied to power supply case (earth ground) • Backplane not tied to Monsoon chassis (earth ground)

– Sigma was ~7.7 counts when • +/-5, +/-15, and -28 analog voltage returns tied together at the power supply

– But not tied to power supply case (earth ground)• Backplane tied to Monsoon chassis (earth ground).

– Sigma was ~6.8 counts when ground scheme was based on P.Moore’s recommendation

• +/-15 common returns tied together at the power supply• +/-5 common returns tied together at the power supply• +5VD, +3.3VD, & -28VA returns kept separate• Backplane tied to Monsoon chassis (earth ground).

– Sigma was ~6.00 counts when• +/-5, +/-15, and -28 analog voltage returns tied together at the power supply

– & tie to power supply case (earth ground)• +5 digital voltage return tied to power supply case (earth ground)• Backplane tied to Monsoon chassis (earth ground).



• Conclusion for uRAM vs Voltage Regulator: – Sigma was lowest-

• ~6.0 counts – Using a +3.3V, VOLTAGE REGULATOR for +3.3VD

» Driven from Vicor +5VD Supply– +/-5, +/-15, and -28 analog voltage returns tied together at the power supply

» & tied to power supply case (earth ground)– Backplane ground tied to Monsoon chassis (earth ground)– +5 digital voltage return tied to power supply case (earth ground)

• ~6.45 counts – Using the uRAM for +3.3VD with same setup as with voltage regulator above except

» +5 and +3.3 digital voltage returns tied together at the power supply and tied to power supply case (earth ground)

– Sigma was highest-• Either voltage regulator or uRAM installed

– +/-5, +/-15, and -28 analog voltage returns tied together at the power supply» & tied to power supply case (earth ground)

– +5 and +3.3 digital voltage returns kept separate» But not tied to power supply case (earth ground)

– Sigma moved around –• When earth ground references was not at all 3 points

– Backplane– +/-5, +/-15, and -28 analog voltage returns at the power supply– +5 and +3.3 digital voltage returns at the power supply



• LOWEST SIGMA CONFIGURATION – TIE ALL POWER SUPPLY RETURNS TO POWER SUPPLY

CASE(EARTH GROUND)

– TIE BACKPLANE GROUND TO MONSOON CHASSIS (EARTH GROUND)

– USE +3.3VD VOLTAGE REGULATOR, DRIVEN FROM VICOR +5VD.


Noise Test Software Setup

• Monsoon is running Fermilab focal plane with Monsoon Command Bar on cyclone:/home/monsoon/cfg/_fnal/.

• Code has been added to panSaver by Tao to automatically calculate the # of pixels, pedestal voltage (mean) and Sigma.

• Exposure can be run in continuous loop by using Labview code written by Inga.• Short runs (.5Kx2K CCD) with Labview code were used to quickly analyze

modifications to test stand.• Long runs (2Kx4K CCD) were then used to get a more detailed analysis of the

data.• Long run readout analysis in panSaver uses 1,165,026 Pixels.• Readout time is at 6uS/pixel.• All hardware settings are based on Monsoon Command Bar selection: Cube,

Front, Normal, 6us, and with either .5kx1k or 4kx2k size ccds.• Channel 0 & 2 video inputs are used for readout.• Data is also analyzed for a long run using ./noiselast_prepost.sh to validate

accuracy of calculated result in panSaver.• Data is analyzed visually using DS9 or FV4.2.


Noise Test Hardware Setup

• All noise test were done on shielded Monsoon 6-slot DHE conforming to Fermilab specifications using Fermilab video cable and Fermilab CCD passive load terminator.

• Remote sensing for the power supply was removed & local sensing used.

• Power supply tests ran:1. Vicor supply, using +3.3VD and uRAM Filter connected to

shielded Monsoon 6-slot DHE.2. Vicor supply without +3.3VD, instead using a +3.3v voltage

regulator driven from +5V and connected to shielded Monsoon 6-slot DHE.


Noise Test Hardware Setup

3. Earth ground references/power supply return configurations:• Backplane ground plane connected to Monsoon chassis• Power supply analog returns connected to power supply case

with/without backplane ground connected to Monsoon chassis• Power supply digital returns connected to power supply case

with/without backplane ground connected to Monsoon chassis• Power supply analog & digital returns connected to power supply

case with/without backplane ground connected to Monsoon chassis

4. Power supply common returns with 3 configurations:• +/-5, +/-15, and -28 analog voltage returns tied together at the power

supply & +5 and +3.3 digital voltage returns tied together at the power supply

• All returns separated• +/-15V analog voltage returns tied together, +/-5V analog voltage

returns tied together, -28V analog voltage return separate (due to not using +48V), & +5V and +3.3V digital voltage returns separated.


• Test rack connects to earth ground thru power strip going to outlet & provides one point of reference for earth ground

• Grounding strap connects Vicor case to rack to bring power supply case earth ground & rack earth ground together

• Grounding strap connects backplane ground to Monsoon chassis to bring backplane ground plane & chassis/rack earth grounds together.

• Another set of power supply cable analog & digital earth ground wires connected together at the Monsoon crate & at the case

• +48VAN is not connected, thus not used during the testing

Earth Grounding & Shielding Schemes Notes


Vicor Supply with URAM Active Filter Ground/Shield Scheme

DOUBLE-CLICK ICON TO SEE MORE DETAIL

Acrobat Document


Vicor Supply With Voltage RegulatorGround/Shield Scheme

DOUBLE-CLICK ICON TO SEE MORE DETAIL

Acrobat Document


Vicor Supply Test Results With uRAM FrompanSaver Window

Channel 0 Channel 2

Test Date Test Stand Setup Mean RMS Mean RMS Notes/Results

Test1 10-Apr-07

Vicor supplies, w/ uRAM. Analog RTNs tied together. Digital RTNs are separated. Analog RTNs connected

to EGND @ power supply case.

80,267 12.53 82,547 12.00Get a measurement using Vicor supply. ENGD is referenced @ analog RTNs of power supply.

Test2 10-Apr-07Same as Test 1, except Digital RTNs

are tied together & NOT tied to Egnd. 80,281 15.91 82,573 15.33

Tie Digital RTNs together & take measurement.

Test3 10-Apr-07

Same as Test2, except Analog & Digital RTNs are BOTH tied to EGND

@ power supply case.80,295 8.43 82,576 8.06

Attach both Analog & Digital RTNs to ENGD & take

measurement.

Test4 10-Apr-07

Same as Test 3, except backplane GND is tied to EGND at Monsoon

case.80,301 6.40 82,573 6.56

Get a measurement with EGNDs @ Analog RTNs, Digital RTNs, &

Backplane GND.

Test5 10-Apr-07Same as Test4, except ONLY

Backplane GND is tied to EGND.80,318 7.81 82,601 7.68

Get a measurement with backplane @ EGND. Analog & digital RTNs get their EGNDs thru backplane GND/EGND.

Test 6 10-Apr-07

Based on P.Moore scheme. +/-15VA RTNs are tied together; +/-5VA RTNs are tied together; +5VD, +3.3VD, & -

28VA RTNs are separate.

80,314 8.12 82,579 8.06

Get a measurement based on P. Moore scheme where the

common voltages have their RTNs together. EGND is @

backplane ONLY.


Vicor Supply Test Results With Volt. RegulatorFrom panSaver Window

Channel 0 Channel 2

Test Date Test Stand Setup Mean RMS Mean RMS Notes/Results

Test1 11-Apr-07

Based on P.Moore scheme. +/-15VA RTNs are tied together; +/-5VA RTNs

are tied together; +5VD, & -28VA RTNs are separate.

80,362 6.93 82,640 6.63

Get a measurement based on P. Moore scheme where the

common voltages have their RTNs together. EGND is

referenced @ backplane ONLY.

Test2 11-Apr-07Same as Test1, except Analog RTNs

tied together. 80,319 8.25 82,606 7.35

Get a measurement with Analog RTNs tied together & EGND is

referenced @ backplane.

Test3 11-Apr-07Same as Test 2, except Analog RTNs

are tied to Monsoon case (EGND).80,349 6.48 82,622 6.24

Get a measurement with both Analog RTNs & backplane @

EGND.

Test4 11-Apr-07

Same as Test3, except Analog & Digital RTNs are BOTH tied to EGND

@ power supply case.80,354 6.08 82,623 6.0

Attach Analog RTNs, Digital RTNs, & backplane GND to

ENGD & take measurement.

Test5 11-Apr-07Same as Test 4, except ONLY Analog

& Digital RTNs are Tied to EGND. 80,309 7.97 82,601 7.55Get a measurement with ONLY Analog & Digital RTNs tied to

EGND.

Test6 11-Apr-07Same as Test5, except ONLY Analog

RTNs are tied to EGND.80,311 13.82 82,587 13.11

Get a measurement with ONLY Analog RTNs tied to EGND.


Test Results withnoiselast_prepost.sh

Test #1 - Vicor Supply with uRAM(CH1-Top Plot, CH2-Bottom Plot)




Test Results with noiselast_prepost.sh


***BEST RESULTS w/ uRAM***


Test #1 - Vicor Supply with Volt. Reg.(CH1-Top Plot, CH2-Bottom Plot)


Test #4 - Vicor Supply with Volt. Reg.(CH1-Top Plot, CH2-Bottom Plot)

***BEST RESULTS W/ VOLT. REG.***


Conclusion/Next…

• Lowest noise was achieved:– Using a shielded DHE– Using +3.3V voltage regulator being driven from Vicor +5VD– Tying power supply analog returns together and connecting to Vicor case (earth ground)– Tying Vicor +5VD return to Vicor case (earth ground)– Tying backplane ground to Monsoon chassis (earth ground)

• Is the sigma low enough?– If so:

• Compare grounding/shielding schemes between Monsoon prototype DHE & shielded Monsoon DHE

• Implement changes to prototype DHE and run more tests• Run more tests on modified prototype DHE:

– Run 2 channels @ 4uS/Pixel– Run 1 ccd Acq. Board/8 channels @ 4uS– Run 1 ccd Acq. Board/12 channels @ 4uS– Run fully loaded DHE, 3 12 ch. CCD & 2 CBB boards/36 channels @ 4uS– Load system down with lowest Vicor configuration to see if Sigma will lower with increased

current load– Implement suggestions from others to lower noise

Todd Moore for the DES CollaborationApril 20 th, 20071 Quick Summary of Noise Test Results. Noise...

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