简介:Thestabilityofthedrivecurrentisveryimportantforalaserdriver,whileitisdifficulttomaintainthecurrentstableatahighvalueforthelaserdriver.Ontheotherhand,therangeofthedrivecurrentisexpectedtobeaswideaspossibletobeappliedtodifferentkindsoflasers.Inthispaper,ahighcurrentlaserdriverforthesuperluminescentlightemittingdiode(SLED)ispresented,whichisusedintheopticfibergyroembeddedbya0.35mbipolarcomplementarymetal-oxide-semiconductortransistor(BiCMOS)process.Thelaserdriverprovidesautomaticpowercontrolandcertainvalueofcurrentdeterminedbytheexternalresister.Thesystemisbasedontheoptic-electricfeedbacktheoryandusestheclosed-loopcontroltechniquetomaintainthedrivecurrentstable.Thesystemiscapableofproducingstablecurrentrangesfrom4mAto200mAwhenthevalueofexternalresisterchanges.
简介:Becauseofrapiddevelopmentinnetworktechnology,Internetusagehasbecomewidespread.Itallowsuserswithsensingdevicestoobtainmedicaldataforhealthcare,suchasphysiologicalsignals,voice,andvideostreamsfromtelemedicinesystems,andtosendthehealthcaredatatoback-enddatabasesystems,creatingaubiquitoushealthcareenvironment.However,thisenvironmentrequiresawidespreadandsuitablenetwork.IPv6(Internetprotocolversion6)isthenext-generationInternetprotocolthatwillbetheprotocoloffuturenetworks;itimprovesmanyshortcomingsofIPv4.Inthispaper,weproposeanIPv6/IPv4U-home-caretestsystemandanalyzethenetwork’sparametersthoughaseriesoftestsbyadjustingnetworkparameterstofindtheoptimaldesignforapplicationsintheIPv6/IPv4U-home-careservicesoastoassuregoodperformanceandhighquality.