l:2005-11-25;:2006-01-12bv.2s!9何峥嵘(S0S/v=E,i400060)K1:简要介绍了运算放大器电路包含的噪声类型。运用标准的电路理论和噪声模型,计算运算放大器电路的噪声。结合反相、同相和差分输入的运算放大器电路分析举例,讨论了推算运算放大器电路噪声的方法。最后,给设计人员提供了有关噪声设计的建议和方法。1oM:运算放大器;噪声;谱密度;均方值;总的均方根噪声ms|:TN722.7+7 DSM:A cI|:1004-3365(2006)02-0148-06Noise Analysis and Design of Operational Amplifier CircuitsHEZheng-rong(SichuanInstituteof Solid-StateCircuits, ChinaElectronics Technology Group Corporation, Chongqing 400060, P. R. China)Abstract:Different noisetypesinoperational amplifier(op-amp) circuits are described. Standard circuit theoryand noisemodels are used to calculate noises in op-amp circuits. With inverting, noninverting and differential op-ampcircuitsasexamples, methods to noise calculations areillustrated. Finally, useful advices and techniques fornoisedesignareprovided.Key words:Operationalamplifier;Spectraldensity;Averagemean-squarevalue;Total root-mean-square noiseEEACC:12201引言8=io,8M。8=)B?,4A,80。CVC8M。oKa,L=i1。Y,o.2。*.2,81o1T。1928M,J. B. John-son,.20=!9bvvY,B0L2K,A!.1z1/VsK。V/ HzA/ Hz.2,YV.2。Ce.2qz9F(Hz)79F,yN,.2.2zZ9F(Hz)79F。.2r9qM,VV.2?T。2运算放大器电路的噪声类型bvi5.2:.2(Shot Noise).2(Thermal Noise).2(FlickerNoise).2(Burst Noise).2(AvalancheNoise).2).2bvYvY,P,9?h,.2sVIn。/B.2。2. 1.2.29M。HV(pn),8),.23。VBeYq,yN,v、(iD3622006M40MicroelectronicsVol.36, 2Apr.2006Hi。.2Yl(M(Z,:i2n =(i-iD)2 =2qiD dfT,q0(1.6210-19C),dfqs,qiDlq,A2 /Hz。.2.2(BqS=.2|),(TBHMq.2wLH,.2S),q(。N,.21。2. 2.2.28=0(0b)?53。.2iE。.29.2,.21,1。8.2VV,r1BX.2E,iBX.2E。.2.2(ZsY:e2 =4kTR df, i2 =(4kT/R)dfT,ko:%(1.3810-23J/K),T,R8E(),dfqs,4kTR4kT/Rlq(V2 /HzA2 /Hz)。2. 3.2.291/f.2,iq,iOy。.291,(Z:e2 =(k2e /f)df , e2 =(k2i /f)dfT,kekiaq(sY), fq,dfqs,k2e /fk2i /flq,V2 /HzA2 /Hz。2. 4.2.29.2,VC()KM。YV2H,.2Pz2(q100Hz/2)。C8Ji0MM1。Pb!T,?vvhl.2。2. 5).2).2pnTQ_,H3。pn=,#YR3E!R1 、R2iE,PKl。R3 = R1R2R1 +R2*,ERrms = 8kTR3df4.1.2同相/反相输入运算放大器电路中运放本身的噪声分析m7r3.2E2p =epR1 +R2R12dfm8r3.2E2np =inpR3R1 +R2R12dfm9r3.2E2nn =(innR2)2df8,bvb&.2:EOArms = E2p +E2np +E2nnEOArms= e2p R1+R2R12+(inpR3)2 R1+R2R12+(innR2)2 df4.1.3同相/反相输入运算放大器电路的总噪声8,9(Z.2:150:bv.2s!92006METrms = E2Rrms +E2OArmsETrms =4kT R2 R1 +R2R1+4kT R3R1 +R2R12+e2pR1 +R2R12+inpR32 R1 +R2R12+ innR22dfT-E#M1.2,qM,VsT4;bv&M1.2,.2、.2.2。iA.2.2Tw。.2KVUETrms =ENB(4kTR2A+4kTR3A2)+i2w(R22 +R23A2)finclnfHfL+ENB +e2w A2 fenclnfHfL+ENBT,A= R1 +R2R1,iwl.2(.2,A/ Hz), finc.2Kq,ewl.2(.2,V/ Hz), fenc.2Kq,ENBr.2z(Equivalent Noise Band-width),q+%, fH /fL!ENB。CMOS5bv,.2dl,.2,yN,iw.2V9。N,dl,AR3T,VVsw。yN,TVeETrms = ENB 4kTR2 A+e2w A2 fenclnfHfL+ENB4. 2