Todd Moore for the DES Collaboration April 3rd, 2007 1

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

– Linear supply ground/shield scheme.

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

– Vicor supply with voltage regulator ground/shield scheme.

• Test results.• Conclusion…

Vicor Noise Test Results Ver. 8.0

Todd Moore for the DES Collaboration April 3rd, 2007 2

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.

• Lowest noise was accomplished using linear supplies (~5-6 counts Sigma).

• Sigma remained the same (~6 counts Sigma) when Vicor supplies +5VD, +/-5VA, +/-15VA, -28VA are connected to DHE. +48VA is not connected. +3.3VD is from linear supply.

• Sigma went up when +3.3VD is from Vicor supply (~11 counts). This is due to not having an internal uRAM filter in the Vicor supply. (Vicor doesn’t make a +3.3VD Vicor supply with internal uRAM).

• An external uRAM on the Vicor +3.3VD supply can be used with an decrease in Sigma (~8 counts).

• A possible compromise is to use a +3.3V voltage regulator at the point of load, driven from another +5VD Vicor RAMPAC (~ 6.5 counts Sigma).

Todd Moore for the DES Collaboration April 3rd, 2007 3

Noise Test Hardware Setup

• All noise test were done on shielded DHE conforming to FNAL specifications using FNAL video cable and CCD emulator.

• Power supply tests ran:1. Linear supplies conneted to low-noise Monsoon 6-slot DHE.

2. Vicor supplies +5VD, +/-5VA, +/-15VA, & -28VA connected to Shielded Monsoon DHE. Linear supply +3.3VD is connected to low-noise Monsoon 6-slot DHE.

3. All Vicor supplies including unfiltered Vicor +3.3VD connected to low-noise Monsoon 6-slot DHE.

4. All Vicor supplies including Vicor +3.3VD and uRAM Filter connected to low-noise Monsoon 6-slot DHE.

5. All Vicor supplies including a +3.3v voltage regulator driven from Vicor +5VD and connected to low-noise Monsoon 6-slot DHE.

• Remote sensing was removed & local sensing added.

Todd Moore for the DES Collaboration April 3rd, 2007 4

Noise Test Software Setup

• Monsoon is running Fermilab focalplane 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.

Todd Moore for the DES Collaboration April 3rd, 2007 5

• CCD 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 signal & earth grounds together.

• Analog & digital returns are connected to Vicor case to bring the returns to earth ground.

• The power supply analog & digital earth grounds are connected together at the Monsoon crate & at the case to tie earth grounds & signal grounds together.

Earth Grounding & Shielding Schemes Notes

Todd Moore for the DES Collaboration April 3rd, 2007 6

Linear Supply Ground/Shield Scheme

UofI Linear Power Supply Noise Study Test Stand Grounding Scheme

EGND

Analog Supplies:+/-15VA, +/-5VA,

& -28VA

Vout

RTN

EGND

Vout

RTN

EGND

A/CEGND

A/CEGND

MonsoonBackplane

MonsoonPower Fanout

Board

Vdc GND/RTNs

GND/RTNs Vanalog

Digital Supplies: +5VD, & +3.3VD

Monsoon Case

SHIELD

SHIELD

Rack

FNAL Video Cable Ins/Outs

SHIELD

FNAL CCD Emulator(Floating)

Todd Moore for the DES Collaboration April 3rd, 2007 7

Vicor Supply with Active Filter Ground/Shield Scheme

UofI Vicor Power Supply w/ uRAM Noise Study Test Stand Grounding Scheme

EGND

Vicor Analog Supplies:+/-15VA, +/-5VA, & -28VA

Vout

RTN

EGND

Vout

RTN

EGND

A/CEGND

MonsoonBackplane

MonsoonPower Fanout

Board

+5Vdc GND/RTNs

GND/RTNs

Vanalog

Vicor Digital Supply: +5VD, +3.3VD

Monsoon Case

SHIELD

Rack

FNAL Video Cable Ins/OutsSHIELD

FNAL CCD Emulator(Floating)

+3.3VD

+5VD

RTN

Vout

uRAM+3.3Vdc

SHIELD

Todd Moore for the DES Collaboration April 3rd, 2007 8

Vicor Supply With Voltage RegulatorGround/Shield Scheme

UofI Vicor w/ Vreg Power Supply Noise Study Test Stand Grounding Scheme

EGND

Vicor Analog Supplies:+/-15VA, +/-5VA, & -28VA

Vout

RTN

EGND

Vout

RTN

EGND

A/CEGND

MonsoonBackplane

MonsoonPower Fanout

Board

+5Vdc GND/RTNs

GND/RTNs

Vanalog

Vicor Digital Supply: +5VD

Monsoon Case

SHIELD

Rack

FNAL Video Cable Ins/OutsSHIELD

FNAL CCD Emulator(Floating)

+3.3VDC Vreg

+5VD

+3.3Vdc

SHIELD

Todd Moore for the DES Collaboration April 3rd, 2007 9

Linear Supply Test Results FrompanSaver Window

      Channel 0 Channel 2  

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

Test1

14-Mar-07

Linear supplies are attached to the Shielded Monsoon DHE. +48van is not connected. See

Linear Ground/Shield Scheme.

80,201 5.50 82,511 5.60

Get a baseline measurement with shielded test stand

attached to linear supply.

Test2

19-Mar-07

VICOR supplies are attached to the Shielded Monsoon DHE

except +3.3VD is connected to LINEAR supply. +48van is not connected. FNAL Video cable

& emulator is attached.

80,304 5.65 82,593 5.56

Get a measurement with Vicor supply with filtered

RAMPACs & +3.3VD linear supply.

Test3

20-Mar-07

Same as Test2, 15-Mar-07, except +3.3VD is connected to UNFILTERED VICOR supply.

80,301 10.80 82,591 10.95

Get a measurement with shielded test stand

attached to un-modified Vicor supply.

Test4

29-Mar-07

Same as Test 3, 15-Mar-07, except +3.3VD is attached to VICOR supply WITH URAM

filter installed. See Vicor with Active Filter Ground/Shield

Scheme

80,242 8.00 82,576 8.12

Get a measurement with shielded test stand

attached to Vicor supply including filtered +3.3VD.

Test5

29-Mar-07

Same as Test 2, 19-Mar-07 except +3.3VD is being

generated by the VICOR +5VD with a VOLTAGE REGULATOR. See Vicor With Volt. Regulator

Ground/Shield Scheme

80,261 6.08 82,578 6.63Get a measurement with Vicor supply and Volt.

Regulated +3.3vd.

Todd Moore for the DES Collaboration April 3rd, 2007 10

Test Results withnoiselast_prepost.sh

Vicor Supply with Linear +3.3VD Vicor Supply with unfiltered Vicor +3.3VD

Todd Moore for the DES Collaboration April 3rd, 2007 11

Vicor Supply withFiltered uRAM +3.3VD

Test Results with noiselast_prepost.sh

Vicor Supply with+3.3VD Voltage Regulator

Todd Moore for the DES Collaboration April 3rd, 2007 12

Conclusion/Next…

• Is the sigma low enough?– If so:

• Compare grounding/shielding schemes between Monsoon prototype system & low-noise test stand.

• Implement changes at FNAL and run more tests.

• Run more tests:– 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 on +3.3VD.