简介:ToovercomethelimitationoflowimagesignalswingrangeandlongresettimeinfourtransistorCMOSactivepixelimagesensor,achargepumpcircuitispresentedtoimprovethepixelresetperformance.Thechargepumpcircuitconsistsoftwostageswitchcapacitorserialvoltagedoubler.Cross-coupledMOSFETswitchstructurewithwellcloseandopenperformanceisusedinthesecondstageofthechargepump.Thepixelresettransistorwithgatevoltagedrivenbyoutputofthepumpworksinlinearregion,whichcanaccelerateresetprocessandcompleteresetisachieved.Thesimulationresultsshowthatoutputofthechargepumpisenhancedfrom1.2to4.2Vwithvoltageripplelowerthan6mV.Thepixelresettimeisreducedto1.14nsindark.Imagesmearduetonon-completelyresetiseliminatedandtheimagesignalswingrangeisenlarged.ThechargepumpissuccessfullyembeddedinaCMOSimagesensorchipwith0.3×106pixels.
简介:摘要会议新闻摄像是电视新闻中不可缺少的重要部分,但是许多摄像人员尤其刚从业不久的新手,因为没有掌握必要的摄像技巧,从而导致会议新闻画面单调沉闷,形式呆板枯燥,进而造成观众厌倦,达不到理想的视听传播效果。文中笔者结合多年的摄像经验,总结出拍摄会议新闻摄像应注意的一些问题,以期对广大初学者有所借鉴。
简介:Adoublephotodiode(PD)constructedbyp?/NwelljunctionandN-well/p-subjunctionwasdesignedandfabricatedinaUMC0.18-lmCMOSprocess.BasedonthedevicestructureandmechanismofdoublePD,anovelsmall-signalequivalentcircuitmodelconsideringthecarriertransiteffectandtheparasiticRCtimeconstantwaspresented.Bythismodelwithcompleteelectroniccomponents,thedoublePDcanbeincorporatedinacommercialcircuitsimulator.ThecomponentvalueswereextractedbyfittingthemeasuredS-parametersusingsimulatedannealingalgorithm,andagoodagreementbetweenthemeasurementandthesimulationresultswasachieved.
简介:Byapplyingswitch-signaltheory,thetheoryoftransmissioncurrent-switchesbasedonsymmetricternarylogicisproposed,thistheoryissuitabletodesignsymmetricternarycurrent-modeCMOScircuits.Thesymmetricternarycurrent-modeCMOScircuitsdesignedbyusingthistheorynotonlyhavesimplercircuitstructuresandcorrectlogicfunctions,butalsocanprocessbidirectionalsignals.