Home

News
& Analysis

News & Analysis
Back

Products
& Suppliers

Products & Suppliers
Back

Products
& Suppliers Home

Standards
Library

Reference
Library

Engineering Community

Stay
Informed

Stay Informed
Back

Free Registration

Free Registration

Reference
Library

All

News & Analysis

Products & Suppliers

Standards Library

Reference Library

Community

HOME
REFERENCE
LIBRARY TECHNICAL ARTICLES
SEMICONDUCTORS

5.1: ABSOLUTE VALUE CIRCUIT

5.1: Absolute value circuit

By Scott Hamilton

From An Analog Electronics Companion:
Basic Circuit Design for Engineers and Scientists

5.1 Absolute value circuit

If a man will begin with certainties, he shall end in doubts; but if he
will be content to begin with doubts, he shall end in certainties.

Francis Bacon

The circuit is shown in Fig. 5.1.1 (Philbrick/Nexus 1968). The aim of this is
to produce, from a bipolar input, an output that is the absolute value. What
this means is that for a positive input the output will be positive, while for a
negative input the output will also be positive. (We could also obtain the
'negative' absolute value if desired, though mathematically this is a
contradiction. What is meant is that the signal is inverted.) In mathematical
terms we can write:

(5.1.1)

This circuit has been chosen since it is useful in itself and also since it
provides a very convenient case for a discussion of the effect of negative
feedback on distortion. Here we have deliberately introduced distortion in the
form of the diodes for which the form of distortion is well defined, so we know
what effect it has.

Figure 5.1.1: An absolute value circuit.

The diodes serve as polarity selectors. As noted previously, diodes have a
substantially non-linear response which we might expect to lead to considerable
distortion in the output signal. Typical signals are shown in Fig. 5.1.2, and it
can be seen that there is no evidence of distortion in the output.

Figure 5.1.2: Waveforms for circuit of Fig.
5.1.1.

The general principle of operation is as follows. For
the...

Interested
in this book and others like it? Try EngineeringPro™ from Books24x7®

<<
Previous Excerpt | View
Book Details | Next
Excerpt >>

Copyright Cambridge University Press 2003 under
license agreement with Books24x7

Products & Services

Diodes

Diodes are electronic components that conduct electric current in only
one direction, functioning as a one-way valve. Diodes are manufactured
using semiconductor materials such as silicon, germanium or selenium and are
used as voltage regulators, signal rectifiers, oscillators and signal modulators
/ demodulators.

Search
by Specification | Learn
more about Diodes

Diode Type:

Avalanche Diodes

General Purpose (PN Junction Diodes)

Zener Diodes

Schottky Barrier Diodes

PIN Diodes

Diode Applications:

Rectifier Diode

Limiter

Switching

Modulation

Voltage Regulation

RoHS Compliant?

Required

Must Not Have

Voltage Reference Chips

Voltage references are electronic circuits that produce a constant output
voltage (reference) that is used to compare other voltages in a system.

Search
by Specification | Learn
more about Voltage Reference Chips

PIN Diodes

PIN diodes are three-layer semiconductor diodes consisting of an
intrinsic layer separating heavily doped P and N layers. The charge stored in
the intrinsic layer in conjunction with other diode parameters determines the
resistance of the diode at RF and microwave frequencies.

Search
by Specification | Learn
more about PIN Diodes

Rectifiers

Rectifier diodes are designed for use in rectification circuits.
Rectifiers are used to convert AC to DC.

Search
by Specification | Learn
more about Rectifiers

IC Linear Voltage Regulators

Integrated circuit (IC) linear voltage regulators use
voltage-controlled sources to force a fixed voltage to appear at their
output terminal.

Search
by Specification | Learn
more about IC Linear Voltage Regulators | IC
Linear Voltage Regulators Insights

Topics of Interest

5.1:
References and additional sources

5.1 References and additional sources Jones H. T. ( 1993): Generate absolute
value of difference. Electronic Design 24 June, 86. Mancini R. ( 1998): Window
comparator features independent adjustments.

4.9:
OP-AMP APPLICATIONS USING DIODES

4.9 OP-AMP APPLICATIONS USING DIODES The major limitation of an ordinary
diode, which leads to the principle of using diodes with op-amps, is that an
ordinary diode cannot rectify voltages below V r,...

Chapter
5: Applications to Biostatistics

In this chapter we will study some sequential procedures that are germane to
biostatistics 5.1 The Robbins-Monro Procedure Let Y(x) denote the response to a
stimulus or dose level x and assume that...

Rectifiers
and Power Supply

A rectified voltage (or current) is a voltage with a DC value not equal to
zero and without any change in polarity.  A pure sine wave has a DC (or
average) value of zero because the signal...

Chapter
5: The Discrete Blocks Library

Overview This chapter is an introduction to the Discrete Blocks library.
This is the fourth library in the Simulink group of libraries and contains the
Discrete-Time Linear Systems Sub-Library, and...

Product Announcements

Low-Threshold
PIN Diode Limiter 0.2 to 4.0 GHz

Skyworks Solutions, Inc.

Active
Parts - Diodes

Karl Kruse GmbH & Co. KG

TPSMA6L
- Surface Mount, 600W

Littelfuse, Inc.

View More Product Announcements for Diodes

Home

About IHS
Engineering360

Advertise
With Us

Client
Services

Follow IHS Engineering360

Site Map

Top
Categories

Terms of Use

Privacy
Policy

How We Use
Cookies

© 2016 IHS. All rights reserved. Reproduction in whole
or in part without permission is prohibited.