Characterisa*on setup for a novel CMOS TDI image sensor · A prototype CMOS image sensor (CIS)...

Characterisa*onsetupforanovelCMOSTDIimagesensor

CentreforElectronicImagingTheOpenUniversity,WaltonHall,MK76AAhAp://www.open.ac.uk/ceiFerrucci.Adriano@gmail.com

TesKngwithLabVIEW

JadeCMOSAPSondemoboard

TheDesign

PCBlayoutdesign

ThisPCBdesignhasbeeninspiredfromapreviousboardthatdrivesaCMOSsensorfromTeledynee2v(CIS115).

SummaryAprototypeCMOSimagesensor(CIS)basedontheTimeDelayandIntegraKon(TDI)techniquehasbeendesignedandmanufacturedbyTeledynee2v.WithinthecollaboraKonbetweenTeledynee2vandtheCentreforElectronicImaging(CEI),ithasbeennecessarytocreateasetupinordertocharacterisethesensor.TheprojectconcentratesonthedesignandtestofaPrintedCircuitBoard(PCB)thatwillaccomplishthetaskofdrivingtheimagesensor.Duringtheprojectperiod,ithasbeenpossible tomanufacture thePCB. This gave theopportunity to ascertain theproperdesignof theboardbydriving itwith a custommade LabVIEWsoZware.ThesamePCBandsoZwarewillbeusedinthefuturetoconductafullcharacterisaKonontheimagesensorinordertoverifyitssuitabilityforspaceapplicaKons.

SPINShowcaseTheImperialCollegeLondon,UnitedKingdom6September2017

AdrianoFerrucciunderthesupervisionofKonstanKnD.Stefanov

CentreforElectronicImaging,TheOpenUniversity,WaltonHall,MiltonKeynes,MK76AA,UK

Thecircuitsemployedtocarrytheinputsignalsandsupplyvoltagesare:

•  Howlandcurrentpump,asimplecurrentsourcegeneraKngbiascurrent.

•  InstrumentaKonamplifier,amplifyingthedifferenKalanalogueoutputsandfilteringhighfrequencynoise.

•  OperaKonalamplifiersdrivingseveralbiaslineswithcapaciKveloads.

This has been the task during which, sKll under DesignSpark PCB, the posiKon andorganisaKonofallthecomponentswereestablished.

It had to be done using thefollowingrules:

•  Placing the components in awaythatmakesassemblyandtest easier (for exampleplacing the test points andlabels on the edges of theboard).

•  Use as fewas possible layersfor the tracks, eventuallyusing4layers.

•  Group as much as possiblethe components drawntogetherontheschemaKcs.

•  Miniaturise as much aspossiblethesizeoftheboard.

•  The boardwas assembled byhandintheCEIlabs.

In order to verify the correctoperaKon of the PCB it hasbeen necessary to test allvoltages,clocksandbiases.

To do so, an improvement ofan exisKng tesKng soZwareunder LabVIEW has beendeveloped.

All the biases, voltages andclockshavebeentested.

TimeDelayandIntegraKon(TDI)TDI is a readout technique that allows image acquisiKon that is suitable for specificcondiKonssuchasimagingoffastmovingobjectsorinverylowlightcondiKons.•  This technique is based on the concept of accumulaKng different exposures of the

sameobject,whichismovingrelaKvetothecamera.ItismadebyshiZingthechargesynchronouslywiththemovement.

•  ItallowslargeSignaltoNoiseRaKo (SNR) compared to a“singleshot”capture.

•  It istheperfecttechniqueforimaging of fast movingobjects.

•  This procedure can naturallybedoneinCCDsasthemodusoperandiisbymovingchargesfromrowtorow.

•  Thesensorisbasicallya“CCDi n a CMOS ” , b u t t h emanufacturing technique isthatofaCMOSimagesensor.

•  TD I i n CMOS h a s t h eadvantageofbeAer radiaKonhardness and lower powerdissipaKonthanCCDs.

The whole SchemaKcs design hasbeen carried out with DesignSparkPCB.

The SchemaKcs is the design partthat requires to be as clear and ascoherentaspossible.

•  New schemaKc components forwere created, with all thecorrespondingpinsandlabels.

•  The circuits delivering theanalogueinputsignalshadtobedisplayed on the same sheet asthemaincomponent.

ThesewerethelasttasksbeforehandingthePCBandthesoZwareforasubsequenttestoftheimagesensor.

Picture of Pluto and Charon obtained by TDI imaging (from New Horizons mission, NASA)