标签: piezo

Piezoelectricmotorsareusedindigitalcamerasforautofocus,zoomingandopticalimagestabilization.Theyarerelativelysmall,lightweightandefficient,buttheyalsorequireacomplicateddrivingscheme.Traditionally,thischallengehasbeenmetwiththeuseofseparatecircuits,includingastep-upconverterandanoversizedgenericfull-bridgedriveIC.Theresultinghighcomponentcountandlargeboardspaceareespeciallyproblematicinthedesignofcamerasforevershrinkingcellphones.TheLT®3572solvestheseproblemsbycombiningastep-upregulatorandadualfull-bridgedriverina4mm×4mmQFNpackage.Figure1showsatypicalLT3572Piezomotordrivecircuit.Astep-upconverterisusedtogenerate30VfromalowvoltagepowersourcesuchasaLi-Ionbatteryoranyinputpowersourcewithinthepart’swideinputvoltagerangeof2.7Vto10V.Thehighoutputvoltageofthestep-upconverter,adjustableupto40V,isavailableforthedriversattheVOUTpin.Thedriversoperateinafull-bridgefashion,wheretheOUTAandOUTBpinsarethesamepolarityasthePWMAandPWMBpins,respectively,andtheOUTAandOUTBpinsareinvertedfromPWMAandPWMB,respectively.Thestep-upconverterandbothPiezodrivershavetheirownshutdowncontrol.Figure2showsatypicallayout.TinyDualFull-BridgePiezoMotorDriverOperatesfromLowInputVoltage……

摘要：描述的电路提供了一个从piezofilm传感器的热输出。该电路是一个高输入阻抗的差分电荷放大器，使用三运放仪表放大器配置了几分古典。差阶段拒绝电阻产生的热噪声，并作为一阶高通滤波器。元件值的选择进行了讨论，并一些典型valuese建议。备用配置建议，为克服一些典型电路限制。Maxim>AppNotes>AmplifierandComparatorCircuitsSensorsKeywords:thermalsensor,temperaturesensor,piezoelectric,high-impedanceinput,high-Zbufferamplifier,tempsensor,piezo,chargeJun26,2002amplifier,high-passfilter,noiserejection,common-moderejection,CMR,differentialtosingle-ended,signalconditioning,APPLICATIONNOTE1127AmplifierProvidesSignalConditioningforPiezofilmSensorAbstract:Describedcircuitprovidesathermaloutputfromapiezofilmtransducer.Thecircuitisahigh-input-impedancedifferentialchargeamplifierusingthreeopampsinasomewhatclassicalinstrumentationamplifierconfiguration.Thedifferentialstagerejectsresistor-generatedthermalnoise,andactsasafirst-orderhigh-passfilter.Choiceofcomponentvaluesis……