EECS140 ANALOG CIRCUIT DESIGN LECTURES ON APPLICATIONS University of California Berkeley College of Engineering Department of Electrical Engineering and Computer Science Robert W Brodersen EECS140 Analog Circuit Design Lectures on APPLICATIONS EECS140 ANALOG CIRCUIT DESIGN LECTURES ON APPLICATIONS APP 01 tRISE tFALL 1 01V 1V 0 99V EECS140 ANALOG CIRCUIT DESIGN LECTURES ON APPLICATIONS APP 02 15 20 Years Ago Telephone Filter PCM Codec A D Converter EECS140 ANALOG CIRCUIT DESIGN LECTURES ON APPLICATIONS APP 03 0dB H 40 dB 60Hz 800Hz 3 4kHz 5 8kHz EECS140 ANALOG CIRCUIT DESIGN LECTURES ON APPLICATIONS APP 04 Pole Zero Diagrams A convenient way of visualizing transfer functions the Laplace Transform H S s z 1 s z 1 OUT s IN s s p 1 s p 1 j p 1 20 j 30 z 1 j 10 X O O X p 1 20 j 30 z 1 j 10 S PLANE S j EECS140 ANALOG CIRCUIT DESIGN LECTURES ON APPLICATIONS Poles Zero Diagrams Cont Often what we are really interested in is H i e the magnitude and phase at frequency H H s APP 05 S j j z 1 j z 1 H j p 1 j p 1 To find the magnitude use the fact that magnitude of the products equals the product of the magnitudes so that j z 1 j z 1 j z 1 j z 1 H j p 1 j p 1 j p 1 j p 1 EECS140 ANALOG CIRCUIT DESIGN LECTURES ON APPLICATIONS Poles Zero Diagrams Cont j z 1 X O j p 1 X Lets graphically evaluate H here at j O j40 j j p 1 APP 06 j z 1 O S PLANE S j The magnitude H is the product of the lengths of vectors 3 4 divided by the product of the lengths of vectors 1 2 EECS140 ANALOG CIRCUIT DESIGN LECTURES ON APPLICATIONS Poles Zero Diagrams Cont APP 07 j X O Z O X 0dB H 40dB 60Hz 800Hz 3 4kHz 5 8kHz EECS140 ANALOG CIRCUIT DESIGN LECTURES ON APPLICATIONS APP 08 Poles Zero Diagrams Cont j p3 X X O p3 O X 0dB H 40dB 60Hz 800Hz 3 4kHz 5 8kHz EECS140 ANALOG CIRCUIT DESIGN LECTURES ON APPLICATIONS APP 09 Poles Zero Diagrams Cont 3dB f f Q O f fO EECS140 ANALOG CIRCUIT DESIGN LECTURES ON APPLICATIONS Specification Filter Design APP 10 AMPL dB FREQ LC Prototypes Continuous Time Factorization into 2 Pole 2 Zero sections Biquadratic Chose an Equivalent discrete time structure Use appropriate cont Discrete Transformation i e Bilinear Mapping differentials z 1 Simulate Disirete Time inplementation and compare with original spec DINAP EECS140 ANALOG CIRCUIT DESIGN LECTURES ON APPLICATIONS APP 11 Active RC Filter Continuous Time Switched Capacitor Circuits Sampled Data any Amplitude Digital Filter Sampled Data Quantized Amplitude EECS140 ANALOG CIRCUIT DESIGN LECTURES ON APPLICATIONS APP 12 Digital Filter A D EECS140 ANALOG CIRCUIT DESIGN LECTURES ON APPLICATIONS APP 13 Typical Filter Specifications Continuous time specifications of transfer function H AMPL OUT H H e j IN dB FREQ Amplitude Magnitude in dB 10 log H H H 2 EECS140 ANALOG CIRCUIT DESIGN LECTURES ON APPLICATIONS Typical Filter Specifications Cont Group Delay Group Delay msec FREQ Group Delay APP 14 EECS140 ANALOG CIRCUIT DESIGN LECTURES ON APPLICATIONS Types of 2 Pole Transfer Functions APP 15 Lowpass 2 o H s s 2 o s 2o Q X j P X P j P P Q 2 o 2 o s 1 s 1 4 o Q Q EECS140 ANALOG CIRCUIT DESIGN LECTURES ON APPLICATIONS Types of 2 Pole Transfer Functions Cont Lowpass Q H Q 1 o o Q o sP s 2P 2P s P 1 1 Q P sP 2 sP 2 2 o o o Q APP 16 EECS140 ANALOG CIRCUIT DESIGN LECTURES ON APPLICATIONS Types of 2 Pole Transfer Functions Cont Bandpass o s Q H s s 2 o s 2o Q X j P 1 0 707 H X o o o Q P O APP 17 EECS140 ANALOG CIRCUIT DESIGN LECTURES ON APPLICATIONS Types of 2 Pole Transfer Functions Cont Highpass Highpass 1 Lowpass Bandpass 1 o 2 2 s o Q s 1 o 2 2 o s2 s s 2o s o Q Q X j P Q H P o X O APP 18 EECS140 ANALOG CIRCUIT DESIGN LECTURES ON APPLICATIONS Types of 2 Pole Transfer Functions Cont Bandstop or Notch s o 2 2 Q s o Bandstop 1 s 2 o s 2o s2 o s 2o Q Q X H O j P o X O P APP 19 EECS140 ANALOG CIRCUIT DESIGN LECTURES ON APPLICATIONS Types of 2 Pole Transfer Functions Cont All Pass Delay Equalizer j O X APP 20 P 1 2 Bandpass 2 s o s 2 o s 2o Q Q H s 1 s 2 o s 2o s 2 o s 2o Q Q P P X H Group Delay O H o EECS140 ANALOG CIRCUIT DESIGN LECTURES ON APPLICATIONS APP 21 State Variable Active RC Filter Lowpass Bandpass RQ C V BP V IN C R R V LP EECS140 ANALOG CIRCUIT DESIGN LECTURES ON APPLICATIONS State Variable Active RC Filter Cont R1 1 RF 2 R2 R R OUT 1 F 2 F R1 R2 OUT APP 22 EECS140 ANALOG CIRCUIT DESIGN LECTURES ON APPLICATIONS State Variable Active RC Filter Cont R RQ V IN 1 1 RC s V BP 1 1 RC s 2 1 RC 2 V LP o V IN 1 2 1 2 s o s o2 s s RC C RC Q 1 o RC R Q Q R V LP APP 23 EECS140 ANALOG CIRCUIT DESIGN LECTURES ON APPLICATIONS State Variable Active RC Filter Cont 1 S V BP RC o S 2 V IN 2 o 1 1 S S o S S Q RC C RC Note GAIN is Q at o instead of 1 as required for a canonical bandpass Highpass Highpass 1 Lowpass Bandpass Using a 3 RD OP AMP we form the sum 1 V HIGHPASS V IN V LP V BP Q APP 24 EECS140 ANALOG CIRCUIT DESIGN State Variable Active RC Filter Cont Bandstop Bandstop 1 Bandpass V BANDSTOP V IN 1 V BP Q All Pass Allpass 1 2 Bandpass V ALLPASS V IN 2 V BP Q LECTURES ON APPLICATIONS APP 25 EECS140 ANALOG CIRCUIT DESIGN LECTURES ON APPLICATIONS APP 26 Active RC Filters Integrator or State Variable Configurations Basic Element is the OP AMP Integrator i OUT iin C IN R Virtual Ground OUT EECS140 ANALOG CIRCUIT DESIGN LECTURES ON APPLICATIONS APP 27 Active RC Filters Integrator or State Variable Configurations Cont i OUT iin in 0 i in in R R SC OUT in R 0 OUT SC OUT i OUT 1 SC OUT 1 1 H s in RC S H s s j 1 RC j EECS140 ANALOG CIRCUIT DESIGN LECTURES ON APPLICATIONS APP 28 Active RC Filters Integrator or State Variable Configurations Cont Scaling of the internal node voltages for maximum dynamic range IN 1 2n1 2n2 2 OUT EECS140 ANALOG CIRCUIT …
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