Login
Register

ENGLISH简体中文
(Chinese)日本語
(Japanese)РУССКИЙ
(Russian)

Products

Solutions

Design

Buy

Support

About Us

My Maxim

Maxim > Design
support > App notes
> A/D and
D/A Conversion/Sampling Circuits > APP
4107
Maxim > Design support >
App notes
> Amplifier
and Comparator Circuits > APP 4107

Sep 07, 2007

Keywords: op amp, glossary, common-mode
rejection, common-mode input resistance, gain-bandwidth
product, input bias, input offset, differential mode, output
impedance, power dissipation, output voltage swing,
power-supply rejection, slew rate

Download,
PDF format (30kB)

[?]

APPLICATION NOTE 4107

Operational Amplifiers Glossary of Key Terms

Abstract: This
application note is a collection of operational amplifier (op
amp) terms and their specifications. The article provides a
handy reference guide for designers.

This
glossary defines the operational
amplifier (op
amp) specifications that are commonly found in the
Electrical Characteristics Table of the typical op-amp data
sheet.

Common-Mode Input Resistance
(RINCM)
For op amps
operating in the linear
region, this term defines the input common-mode
voltage
range divided by the change in input bias current
across that range.

DC Common-Mode Rejection
(CMRDC)
This is a measure of the op amp's
ability to reject DC signals present in equal measure at
both inputs. CMRDC can be calculated using the
common-mode voltage range (CMVR)
and the change in peak-to-peak input offset voltage across
that range.

AC Common-Mode Rejection
(CMRAC)
CMRAC is a measure of the
amplifier's ability to reject AC signals present in equal
measure at both inputs. It is a function of differential
open-loop gain divided by common-mode open-loop gain.
CMRAC is usually specified at a given frequency
and over a DC common-mode range.

Gain-Bandwidth Product (GBW)
This
is the constant product AOL * ƒ in the
region of the -20dB/decade rolloff on the open-loop Gain
vs. Frequency characteristic curve.

Input Bias Current (IB)
For op amps
operating in the linear region, this term indicates the
current that flows into the inputs, averaged.

Input Bias-Current Drift
(TCIB)
This is the change in input bias
current due to the change in temperature.
TCIB is usually expressed in pA/°C.

Input Offset Current (IOS)
This is
the difference between the currents flowing into the two
inputs.

Input Offset-Current Drift
(TCIOS)
This is the change in input offset
current due to the change in temperature. TCIOS
is usually expressed in pA/°C.

Differential-Mode Input Resistance
(RIN)
This is the change in input offset
voltage divided by the change in input current. This change
results from that changing voltage. For either input with
the other input connected to a fixed common-mode
voltage:

Output Impedance (ZO)
For op amps
operating in the linear region, this term indicates the
small-signal internal impedance
of the output terminal.

Output Voltage Swing (VO)
This term
indicates the maximum peak-to-peak voltage swing that the
output can achieve without clipping the signal.
VO is usually specified into a given load resistance
and relative to the supply rails.

Power Dissipation (Pd)
This is the
quiescent
power dissipated by the device under the given supply
voltages. Pd is usually specified with no load
attached to the output.

Power-Supply Rejection Ratio (PSRR)
This
measures the ability of an amplifier to maintain its output
voltage unchanged as the supply voltage varies. PSRR is
often determined by measuring the change in input offset
voltage as a result of the change in power-supply
voltage.

Slew Rate (SR)
This is the maximum
large-signal rate of change of the output voltage divided by
the amount of time that the change takes to occur. SR is
usually expressed in V/µs, and sometimes listed separately
for positive-moving and negative-moving signals.

Supply Current (ICC,
IDD)
This indicates the quiescent current
required by the device at the given supply voltage. These
terms are usually specified with no load attached to the
output.

Unity Gain Bandwidth (BW)
This is the maximum
frequency for which the open-loop gain is greater than
one.

Input Offset Voltage (VOS)
This
indicates the voltage difference that, when applied
differentially to the inputs, causes the output to equal
zero.

Input Offset-Voltage Drift
(TCVOS)
This indicates the change in input
offset voltage over temperature, usually expressed in
µV/°C.

Input Capacitance (CIN)
For op amps
operating in the linear region, CIN is the
capacitance of either input terminal with the other input
terminal connected directly to ground.

Input Voltage Range (VIN)
This is
the voltage range at the inputs over which the amplifier
operates with predictable results. VIN is usually
expressed relative to the supply rails.

Input-Voltage Noise Density
(eN)
For op amps, input voltage noise can be
modeled as a series noise-voltage source
connected to either input. eN is usually
expressed in nV /
(nanovolts per root Hertz)
and usually specified at a single frequency.

Input-Current Noise Density
(iN)
For op-amps, input current noise can be
modeled as two noise current sources, one connected from
each input to a common point. iN is usually
expressed in pA /
(picoamps per root Hertz) and usually specified at a single
frequency.

Automatic updates
Would you like to be
automatically notified when new application notes are
published in your areas of interest? Sign
up for EE-Mail™.

Download,
PDF format (30kB)
APP 4107: Sep 07, 2007

AN4107, AN 4107, APP4107,
Appnote4107, Appnote 4107

|

|

|     Privacy Policy
|     Legal Notices

Copyright © 2011 by Maxim Integrated
Products