# Design of negative feedback amplifier configurations#

## Application of negative feedback#

Amplifiers: application of negative feedback

Negative (corrective) feedback can be regarded as a powerful design technique. It trades power gain for quality improvement and facilitates orthogonal design of the different performance aspects.

**Presentation**

The presentation "Amplifiers: application of negative feedback"shows that accurate, low-noise and power-efficient amplifiers can be realized through application of negative feedback.

**Presentation in parts**

Amplifiers: application of negative feedback (parts)

**Videos**

**Study**

Chapter 7.1

Feedback amplifiers: orthogonal design sequence

In electronic information processing systems, amplification is one of the most important basic functions. Since the basic amplification mechanism, as it is found in biased ‘active’ devices, suffers from many imperfections, negative feedback is often exploited as powerful error reduction technique.

The application of negative feedback, together with proper sequencing of the design of various performance aspects makes it possible to prevent or minimize design iterations and have an early awareness of possible show-stoppers.

**Presentation**

The presentation "Design of application-specific negative feedback amplifiers with operational amplifiers" gives the outline of the design sequence of high-performance negative feedback amplifiers.

**Presentation in parts**

Design of application-specific negative feedback amplifiers with operational amplifiers (parts)

**Video**

## Design of amplifier types#

Amplifiers: design procedure feedback configurations

The design of negative amplifier configurations follows a strict procedure based on sensing and comparison techniques.

**Presentation**

The presentation "Feedback amplifiers: design procedure" illustrates the procedure for the design of a negative-feedback amplifier that accurately relates the desired electrical quantity at the load of the amplifier to that of the signal source.

**Presentation in parts**

Feedback amplifiers: design procedure (parts)

**Video**

EE3C11 lecture 7 Feedback amplifiers design procedure

**Study**

Chapter 7.2

Amplifiers: design of single-loop feedback configurations

Sensing of the load quantity and nullification of the difference between the feedback quantity with the source quantity form the basis of the design procedure of negative feedback amplifiers.

**Presentation**

The presentation "Design of Single-loop Negative Feedback Amplifier Configurations" illustrates the application of the design procedure for negative feedback amplifiers to the design of single-loop negative feedback amplifiers:

The voltage amplifier

The transadmittance amplifier

The transimpedance amplifier

The current amplifier

It illustrates a number conflicts between design aspects for passive feedback amplifiers:

Amplifier type

Sign of the transfer

Port isolation

**Presentation in parts**

Design of Single-loop Negative Feedback Amplifier Configurations (parts)

**Video**

Amplifiers design of single-loop feedback configurations (11:41)

**Study**

Chapter 7.2

Feedback amplifiers: ideal gain

The conceptual design or functional design of negative feedback amplifiers comprises the design of the feedback networks and their interconnection with the source, the load and nullors (ideal controllers).

**Presentation**

The presentation "Negative Feedback Amplifier Configurations: Ideal Gain and Controller" gives a definition of the gain of negative feedback amplifiers that have ideal controllers (nullors). The implications of controller imperfections will be discussed at a later stage.

**Presentation in parts**

Negative Feedback Amplifier Configurations: Ideal Gain and Controller (parts)

**Video**

Negative Feedback Amplifier Configurations Ideal Gain and Controller (3:35)

**Study**

Chapter 7.3

Amplifiers: multiple-loop feedback configurations

Each transmission-1 two-port parameter of an amplifier can be given an accurate nonzero value with the aid of a feedback network around a high-gain controller.

**Presentation**

The presentation "Design of Multi-loop Negative Feedback Amplifier Configurations" briefly discusses the design of multiple-loop negative feedback amplifiers.

**Presentation in parts**

Design of Multi-loop Negative Feedback Amplifier Configurations (parts)

**Video**

Amplifiers multiple-loop feedback configurations (2:58)

**Study**

Chapter 7.3, 7.4.1

## Noise performance of negative feedback amplifiers#

Noise performance of feedback amplifiers

In general, insertion of impedances in series and/or in parallel with the signal path should be avoided. They increase:

Energy storage and power losses

Noise

**Presentation**

The presentation "Influence of Feedback Networks on Noise Performance of Negative Feedback Amplifiers" shows that detrimental effects caused by impedances in the feedback networks can be kept low.

**Presentation in parts**

Influence of Feedback Networks on Noise Performance of Negative Feedback Amplifiers (parts)

**Video**

Noise behavior of negative feedback amplifiers (19:42)

**Study**

Chapter 7.4, 7.5

**Exercises**

## Downloads#

The presentations are summarized on the poster: "Application of Negative Feedback"

Determination of show-stopper values of controller noise sources with SLiCAP