BodePlots>A simple technique exists for obtaining anapproximate plot of the magnitude and phase of atransfer function given its poles and zeros. Theresulting diagram is called Bode plots> A transfer function consists of Aproduct offactors of the form s+a20 log1o Vα2 + α2 = 20 log10o /1 +(α / a)2MicroelectronicCircuits
Microelectronic Circuits Bode Plots ➢ A simple technique exists for obtaining an approximate plot of the magnitude and phase of a transfer function given its poles and zeros. The resulting diagram is called Bode plots ➢ A transfer function consists of A product of factors of the form s+a 2 1 0 2 2 1 0 20log a + 20log 1+ ( / a)
BodePlotsFor the case of a zero, bode plot for the typical magnitude andphasetermareshownbelow20logVi+(cufay(dB)+6dB/oclave+20dBkdeeadeActual curve3dBOdB (log scale)0=al=MicroelectronicCircuits
Microelectronic Circuits Bode Plots
BodePlotstan5.70.1a10a0a(logscale)Actual905.70Microelectronic Circuits
Microelectronic Circuits Bode Plots
Example7.1An amplifier has the voltagetransfer function.thebodeplot isshownbelow.10s41T(S)=(1+s/102)(1+s/105)5②3dBA(5)60D：模电课件40波特图.exe(4)20(3)(2)102101041051011061070.11 (rad/s)(log scale)(2)(3)MicroelectronicCircuits
Microelectronic Circuits Example 7.1
7.2the amplifier transferfunction20logT(a)lTI (dB)Bandwidth02wiwa(b)(a)acapacitivelycoupledamplifier(b)a direct-coupledamplifierBandwidth : BW = OH -O,Gain - bandwidth product : GB= AmBW = AmOHMicroelectronic Circuits
Microelectronic Circuits 7.2 the amplifier transfer function (a) a capacitively coupled amplifier (b) a direct-coupled amplifier M M H H L GB A BW A BW = = − Gain - bandwidth product : Bandwidth :