基于高精度低温漂基准源的IF电路设计
Abstract
Inhigh-precisioninertialnavigationsystems,accuracyisanimportantindicatorfor
measuringaircraftandakeyaspectofimprovingaircraftapplicationcapabilities.Theoutput
currentsignalofthequartzflexibleaccelerometerneedstoundergoanalog-to-digital
conversionbeforenavigationcalculationcanbecarriedout.Duetolimitationsinthe
manufacturinglevelofhigh-performanceA/DconversionchipsinChina,aswellas
restrictionsonrelatedtechnologiesimposedbydevelopedcountriesabroad,I/Fconversion
circuitsarestillthemainstreamapplicationinthisfield.Asthenamesuggests,theI/F
conversioncircuitconvertscurrentsignalsintodigitalpulsesignals.Itsworkingprincipleis
currentintegrationandchargebalance,whichtheoreticallydoesnotlosethecurrentsignalof
theaccelerometer.Similartotheprincipleofintegratingandaccumulatingvelocityand
positionininertialnavigationcalculation,thecharacteristicoftheI/Fconversioncircuitisof
greatsignificanceforimprovingnavigationaccuracy.Thisisalsooneofthereasonswhyit
hasanimportantengineeringapplicationpositioninmediumandhigh-precisioninertial
navigationsystems.Therefore,improvingtheaccuracyoftheI/Fconversioncircuitisan
importantlinktoimprovetheoverallaccuracyofinertialinstruments.
ThisprojectoptimizesatypicalI/Fconversioncircuitbasedonahigh-precision
low-temperaturedriftreferencesource,anddesignsahighstabilityandlowtemperature
coefficientcurrent/frequencyconversioncircuit.Thisarticlefirstprovidesabriefintroduction
tothebasicprinciplesofI/Fconversioncircuitsandconstantcurrent