Slopes and Levels: Spice Models to Simulate Vintage Op-Amp Noise

ISBN-13: 9783030994426 / Angielski / Twarda / 2022

Burkhard Vogel

Opis

This book features an extensive index and all Mathcad worksheets.Vinyl is back, tubes/valves are back, on the high-end field SMD-free analog amplification surpasses digitalized chains, and top microphone manufacturers still set on good old op-amps or on fully discrete BJT, FET, and/or tube-driven amplifiers. There is only one problem that is not satisfyingly well solved by the manufacturers: It is the noise production of the active components and the useful reflection in simulation tools, in tables or graphs of the datasheets/data books.Nowadays, mostly surrounded by many digital helping tools, it makes sense using them—also by analog aficionados. It saves cost and time simulating first before spending money. Presented in this book the software tool LTSpice which is the free software solution from Linear Technology (today Analog Devices) that could also be used by full analog lovers to simulate the noise production of their amplifier design. All we need is the right creation approach to develop simulation models for the active components. Inter alia this is already done for tubes and BJTs in the 2nd editions of my “How to Gain Gain” and “Balanced Phono-Amps” books. For op-amps, the missing approaches are presented in the book on hand.It cannot be denied that mathematical software like Mathcad is extremely helpful to find the right equations for graphically presented noise curves which we can find in the literature. Nevertheless, it also works well with other types of math software to fulfill the parameter needs of the here presented modeling approaches for the input referred voltage and current noise of—not only—excellent sounding vintage op-amps, applicable in the audio range from 1 Hz to 100 kHz.

Recenzje

"It is definitely a valuable resource for anyone interested in accurately simulating the noise of op-amp circuits." (Marcel van de Gevel, audioXpress, audioxpress.com, Vol. 54 (3), March, 2023)

Spis treści

1                      Intro

1.1          Reasons for this Book

1.2          Scope of this Book

1.3          Some Rules for a Better Understanding

 

2                      Basics of OPA Noise and Gain

2.1          Noise Sources of an OPA

2.2          General Aspects of OPA Gains

2.3          Test of “Test-OPA-M” with the Adapted Fig. 1.7 Test Arrangement

2.3.1                     Spice parameters for the Test-OPA-M and test arrangement

2.3.2                     Noise voltage

2.3.3                     Noise Current

2.3.4                     Slopes

2.4          Résumé

 

3                      Mathcad Worksheets for Chapter 2

3.1          MCD-WS: Test-OPA-M Open Loop Gain

3.2          MCD-WS: Test-OPA-M Noise Production

 

4                      Non-Inverting OPA Gain Stages

4.1          The Noise Production of the Non-Inverting (Series Configured) OPA Gain Stage

4.2          Output Related

4.3          Input Related

4.4          Résumé

 

5                      Mathcad Worksheet for Chapter 4

5.1          MCD-WS: Non-Inverting Gain Stage

 

6                      Inverting OPA Gain Stages

6.1          The Noise Production of the Inverting (Shunt Configured) OPA Gain Stage

6.2          Output Related

6.3          Input Related

6.4          Résumé

6.5     Important Note Concerning an Additional Load Zx(f) at the (+) Input of the OPA in Fig. 6.2

 

7                      Mathcad Worksheets for Chapter 6

7.1          MCD-WS: Inverting Gain Stage

7.2          MCD-WS: Proof

 

8                      Phono-Amp with OPAs

8.1     The Noise Production of the Phono-Amp

8.2     Main Equations to Calculate the Output Voltage noise and SNs

of the Fig. 8.1 RIAA Phono-Amp – Correlated and Un-Correlated

8.2.1         Main equations for Fig. 8.9 (à la MCD-WS 9.3):

8.2.2         Main equations for Fig. 8.11 (à la MCD-WS 9.3):

8.2.3         Main equations for Fig. 8.1 incl input load (à la MCD-WS 9.3):

8.3          Résumé

 

9                      Mathcad Worksheets for Chapter 8

9.1          MCD-WS: Phono-Amp + 0.0 Ohm with Test-OPA-M

9.2          MCD-WS: Phono-Amp + 1.0 k Ohm with Test-OPA-M

9.3          MCD-WS: Phono-Amp + StaCar with Test-OPA-M

 

 

Part II  Solutions Other Than Slopes of 0.0 dB/dec or -10.0 dB/dec

 

 

10                    The Correlation Matter

10.1        OPA with all its Independent Equivalent Input Noise Sources

10.2        The Voltage Noise Question

10.2.1       The 100% un-correlated state

10.2.2       The 100% correlated state

10.2.3       The general state

10.3        The Current Noise Question

10.3.1       The 100% un-correlated state

10.3.2       The 100% correlated state

10.3.3       The general state

10.4        Real OPAs

10.4.1       Model vs. Data Sheet – Results

10.4.2       Recommended approach to find the correlation state of OPAs,

demonstrated by application of the example OPA AD797

10.5        Résumé

 

11                    Mathcad Worksheets for Chapter 10

11.1        MCD-WS: Test-OPA-01 Correlation Basics

11.2        MCD-WS: AD797 Correlation Basics

11.3        MCD-WS: LT1128 Correlation Basics

 

12                    OPA Noise Modelling

12.1        Intro

12.2        Noise Traces of OPAs

12.3        Goals

12.4        The Voltage Noise Solution

12.5        The Current Noise Solution I – Non-inverted and Non-Correlated Version

12.6        The Current Noise Solution II – Inverted and Correlated Version

12.7        The Final Replacement OPA with Independent and Adjustable Noise Sources

12.7.1       OPA without any correlation of the noise sources

12.7.2       OPA including inverted and 100% correlated current noise sources

12.7.3       Other correlation arrangements

12.8        Comparison Results

 

13                    Mathcad Worksheets for Chapter 12

13.1        MCD-WS: Traces

13.2        MCD-WS: Phono-Amp + StaCar with Test-OPA-N

13.3        MCD-WS: Phono-Amp + 1.0 k Ohm with Test-OPA-N

13.4        MCD-WS: Phono-Amp + 0.0 Ohm with Test-OPA-N

 

 

Part III Solutions for a Selection of Real Op-Amps

 

 

14                    Noise Traces for the Simulation Model of OPAs

– Created with the Example OPA NE5534A

14.1      Intro

14.2        The Simulation Model’s Traces Presented by the Manufacturer

14.3        Data Collection

14.4        Decision about the “right” Traces

14.4.1       Voltage Noise

14.4.2       Current Noise

14.5        Further Material of Noise Trace

14.6        The Final NE5534AN Simulation Model for the New NE5534AN

14.7        What About the Correlation of the Current Noise Sources

of the Original Model?

14.8        What about the OPA’s Input Resistance Rn

14.9        Gain-of-Three-Question

 

15                    Mathcad Worksheets for Chapter 14

15.1        MCD-WS: NE5534AN Voltage Noise Trace

15.2        MCD-WS: NE5534AN Current Noise Trace

 

16                    Example OPA1611

16.1        Intro

16.2   Recommendation for an Adequate Simulation Model of a Voltage Noise Generator

16.3   Recommendation for an Adequate Simulation Model of a Current Noise Generator

16.4   Is it Worth Creating a New Simulation Model for OPA1611’s Noise Purposes?

16.5        What About the Correlation of the Current Noise Sources

of the Original Model?

16.6        The Final OPA1611N Simulation Model

 

17                    Mathcad Worksheets for Chapter 16

17.1        MCD-WS: OPA1611N Voltage Noise Trace

17.2        MCD-WS: OPA1611N Current Noise Trace

 

18                    Example NE5532A

18.1        Intro

18.2   Recommendation for an Adequate Simulation Model of a Voltage Noise Generator

18.3   Recommendation for an Adequate Simulation Model of a Current Noise Generator

18.4   Is it Worth Creating a New Simulation Model for NE5532A’s Noise Purposes?

18.5        What About the Correlation of the Current Noise Sources

of the Original Model?

18.6        The Final NE5532AN Simulation Model

 

19                    Mathcad Worksheets for Chapter 18

19.1        MCD-WS: NE5532AN Voltage Noise Trace

19.2        MCD-WS: NE5532AN Current Noise Trace

 

20                    Example OPA134

20.1        Intro

20.2   Recommendation for an Adequate Simulation Model of a Voltage Noise Generator

20.3   Recommendation for an Adequate Simulation Model of a Current Noise Generator

20.4   Is it Worth Creating a New Simulation model for OPA134’s Noise Purposes?

20.5        What About the Correlation of the Current Noise Sources

of the Original Model?

20.6        The Final OPA134N Simulation Model

 

21                    Mathcad Worksheets for Chapter 20

21.1        MCD-WS: OPA134N Voltage Noise Trace

21.2        MCD-WS: OPA134N Current Noise Trace

 

22                    Example TL071

22.1        Intro

22.2   Recommendation for an Adequate Simulation Model of a Voltage Noise Generator

22.2.1       Recommendation for TI’s voltage noise generator

22.2.2       Recommendation for ST’s voltage noise generator

22.2.3       Remarks about the strange looking datasheet voltage noise curves

22.3   Recommendation for an Adequate Simulation Model of a Current Noise Generator

22.4   Is it Worth Creating a New Simulation Model for TL071’s Noise Purposes?

22.5   What About the Correlation of the Current Noise Sources of the Original Model?

22.6        The Final Simulation Models TL071SN and TL071TN

 

23                    Mathcad Worksheets for Chapter 22

23.1        MCD-WS: TL071SN & TL071TN Voltage Noise Traces

23.2        MCD-WS: TL071SN & TL071TN Current Noise Traces

 

24                    Example SSM-2017

24.1        Intro

24.2   Recommendations for Adequate Simulation Models of the Three Voltage Noise Generators in Fig. 24.4

24.2.1       Mathematics to calculate the noise of the complete amplifier

24.2.2       Simulation model of the two input voltage noise sources

24.2.3       Simulation model of the input voltage noise source

of the 2^nd gain stage

24.3   Recommendation for Adequate Simulation Models for the Two Current Noise Generators in Fig. 24.4

24.4   Is it Worth Creating a Simulation Model for SSM-2017’s Noise Purposes?

24.5        What About the Correlation of the Current Noise Sources?

24.6        The Final SSM2017N Simulation Model

24.7        Test of the Model

24.8        Applications

24.8.1       Microphone amplifier with input load

24.8.2       Summing amplifier

24.8.3       CCIR-1k filter

 

25                    Mathcad Worksheets for Chapter 24

25.1        MCD-WS: SSM2017 Gain & Noise Calculations

 

26                    Summary

26.1        Contents of this Chapter

26.2        Tables

26.3        Data Sources

26.3.1       BJT-input Devices

26.3.2       FET-input Devices

26.3.3       Special Amplifiers and Additional Remarks

O autorze

Burkhard Vogel achieved the degree Diplom-Ingenieur (Telecommunications) from Darmstadt University of Technology, Germany, in 1973. He then decided to follow a general management career path in the high-tech and IT industry in Germany, Switzerland, and Austria. His passion for music and music systems made Mr. Vogel an expert in Phono-Amps and Vinyl Technology. In addition to “Slopes and Levels,” he wrote the RIAA-phono-amp designer guides “The Sound of Silence” and “Balanced Phono-Amps,” rounded up by the triode reference “How to Gain Gain”.