Op-Amp (Operational Amplifier)
Summary
TLDREl script proporciona una introducción a los amplificadores operacionales (op-amps), componentes fundamentales en circuitos analógicos. Se explica que un op-amp es un amplificador de voltaje altamente configurable capaz de realizar operaciones matemáticas. Se discuten sus características, como su alto ganancia y la falta de corriente en sus entradas, siguiendo las 'reglas doradas' del diseño de circuitos. Se presentan aplicaciones básicas como comparadores de voltaje, buffers de voltaje, amplificadores no inversores e inversores, demostrando cómo el op-amp amplifica y/o invierte señales eléctricas. El video concluye prometiendo futuras discusiones sobre aplicaciones prácticas más avanzadas.
Takeaways
- 🔍 Un amplificador operacional (op-amp) es un componente básico en los circuitos analógicos que amplifica la señal eléctrica y realiza operaciones matemáticas.
- 🎚️ Los op-amps tienen dos entradas, una inversora y otra no inversora, y una salida, y su diseño permite realizar comparaciones y cálculos con señales de voltaje.
- 🔌 El suministro de energía de un op-amp suele ser de 5 a 15 volts tanto positivo como negativo, lo que permite que la salida oscile entre ambos niveles.
- 📊 La ganancia de un op-amp es una medida de cuánto más grande es la salida en comparación con la diferencia de voltaje de entrada.
- 🔄 El op-amp puede trabajar en configuraciones de bucle abierto y bucle cerrado, siendo el bucle cerrado esencial para limitar la ganancia y realizar amplificaciones y operaciones matemáticas.
- 👉 Las reglas doradas del diseño de circuitos con op-amps incluyen que la ganancia de bucle abierto es infinita, no hay corriente en las entradas y la salida ajusta para eliminar diferencias de voltaje en las entradas.
- 🔌 El op-amp como comparador de voltaje se satura cuando la salida alcanza los límites del suministro de energía.
- 🔗 La retroalimentación es crucial en los op-amps para controlar la ganancia y evitar la saturación, permitiendo realizar amplificaciones y operaciones matemáticas de manera efectiva.
- 🔄 El op-amp como buffer de voltaje permite mantener la relación de divisor de voltaje sin que la carga afecte la señal de entrada.
- 📈 El amplificador no inversor es una aplicación del op-amp que amplifica y mantiene la misma fase de la señal de entrada, ajustando la ganancia con resistencias externas.
- 📉 El amplificador inversor es una aplicación del op-amp que amplifica y invierte la señal de entrada, también utilizando resistencias para ajustar la ganancia.
Q & A
¿Qué es un operacional amplificador (op-amp) y qué hace?
-Un operacional amplificador, o op-amp, es un circuito electrónico diseñado para amplificar la señal de voltaje. Su función principal es aumentar la magnitud de una señal eléctrica débil, tomando una señal de entrada y haciendo que sea más poderosa en la salida.
¿Por qué se necesita un amplificador para señales eléctricas?
-Se necesitan amplificadores porque muchas señales eléctricas son débiles y necesitan ser reforzadas antes de poder ser procesadas, transmitidas o usadas para impulsar dispositivos de salida, como en el caso de un sistema de audio con un micrófono y un altavoz.
¿Cómo surgieron los op-amps en el contexto de las computadoras analógicas?
-Los op-amps surgieron para realizar cálculos matemáticos con voltajes y corrientes en computadoras analógicas. Permitían realizar operaciones matemáticas complejas con señales de voltaje, como sumar, restar, dividir, multiplicar, calcular derivadas e integrales, con ajustes mínimos.
¿Cuál es la función de los sensores de temperatura en un ejemplo de computadora analógica?
-Los sensores de temperatura en un ejemplo de computadora analógica se utilizan para medir y proporcionar la temperatura de diferentes contenedores, donde la salida de voltaje de cada sensor está proporcional a la temperatura del contenedor.
¿Cómo se representa un op-amp en un diagrama de circuito?
-Un op-amp se representa en un diagrama de circuito por una forma de triángulo simple, donde los componentes internos no se representan individualmente.
¿Cuáles son las dos entradas de un op-amp y qué significan?
-Un op-amp tiene dos entradas: una llamada entrada inversora (con una marca de signo negativo o menos) y otra llamada entrada no inversora (con una marca de signo positivo o más).
¿Qué son las reglas doradas del diseño de circuitos con op-amps y cuáles son?
-Las reglas doradas son pautas para diseñar circuitos con op-amps basadas en sus características. La primera regla dice que la ganancia de banda abierta de un op-amp es infinita en teoría. La segunda regla indica que no hay corriente entrando o saliendo de las entradas del op-amp. La tercera regla establece que con retroalimentación negativa, la salida del op-amp cambiará para hacer que la diferencia de voltaje entre sus entradas sea cero.
¿Qué es un amplificador no inversor y cómo se configura?
-Un amplificador no inversor es una aplicación básica del op-amp donde la entrada se conecta a la entrada no inversora y la salida se conecta a la entrada inversora a través de un resistor. La ganancia de este amplificador se ajusta mediante los valores de los resistores R1 y R2.
¿Cómo funciona un amplificador inversor y cuál es su ganancia?
-Un amplificador inversor toma la entrada en la entrada inversora a través de un resistor R1 y tiene un camino de retroalimentación desde la salida al inversor a través de un resistor R2. La ganancia de este amplificador es -R2 dividido por R1, lo que indica que la señal de entrada se invertirá y se amplificará según la ganancia establecida.
¿Qué es un comparador de voltaje y cómo funciona?
-Un comparador de voltaje es una configuración del op-amp que se usa para comparar dos voltajes y dar una salida según la diferencia entre ellos. Si la diferencia de entrada es cero, la salida también es cero. Si la entrada no inversora tiene un voltaje ligeramente más alto, la salida se satuarará en el voltaje de alimentación positivo. Si es más baja, se satuarará en el voltaje de alimentación negativo.
¿Qué es un buffer de voltaje y cómo ayuda a evitar la distorsión en un divisor de voltaje?
-Un buffer de voltaje es una configuración del op-amp donde la salida se conecta directamente a la entrada inversora. Ayuda a evitar la distorsión en un divisor de voltaje al proporcionar la corriente del suministro de energía conectado al op-amp, eliminando así la alteración de los valores del divisor de voltaje debido a la carga.
Outlines
🔌 Introducción a los Amplificadores Operacionales (Op-Amp)
El Op-Amp, o amplificador operacional, es una pieza clave en la construcción de circuitos analógicos electrónicos, junto con resistencias, capacitores, diodos y transistores. Su función principal es aumentar la magnitud de una señal eléctrica, tomando una señal de entrada débil y produciendo una señal de salida más potente. Este proceso es esencial para sistemas electrónicos que requieren señales fuertes para procesar, transmitir o activar dispositivos de salida, como en el caso de un sistema de audio que utiliza un micrófono y un altavoz. Además, los Op-Amps tienen la capacidad de realizar operaciones matemáticas variadas con ajustes mínimos, lo que los hace versátiles para tareas como la diferenciación, integración y otros cálculos con voltajes. Se fabrican comúnmente como circuitos integrados (ICs) para facilitar su uso en diseños de circuitos.
🔌 Características y Configuraciones del Op-Amp
Los Op-Amps cuentan con entradas de inverting y non-inverting, y tienen una amplia ganancia, que es la relación entre la diferencia de voltaje de entrada y la voltaje de salida. Esta ganancia es un parámetro crítico que define el factor de amplificación del Op-Amp. Aunque no se pueden utilizar como amplificadores diferenciales por sí solos debido a su alta ganancia interna, pueden funcionar como comparadores de voltaje cuando se conectan a una fuente de alimentación. La salida del Op-Amp puede 'saturar', alcanzando los límites de la fuente de alimentación, tanto positiva como negativa. Además, se pueden configurar en circuitos abiertos para crear comparadores o en circuitos cerrados con retroalimentación para realizar amplificación y operaciones matemáticas.
🔌 Reglas de Oro y Aplicaciones Básicas del Op-Amp
Las reglas de oro para el diseño de circuitos con Op-Amp son importantes para comprender su funcionamiento. La primera regla establece que la ganancia de banda abierta es teóricamente infinita, aunque en la práctica es de alrededor de 200,000. La segunda regla afirma que no hay corriente que entre o salga de las entradas del Op-Amp, lo que implica una impedancia de entrada infinita. La tercera regla dice que con retroalimentación negativa, la salida del Op-Amp cambiará para eliminar cualquier diferencia de voltaje entre sus entradas. Aplicaciones básicas del Op-Amp incluyen el comparador de voltaje, el buffer de voltaje y el amplificador no inverso, donde se utiliza la retroalimentación para controlar y limitar la ganancia, y se pueden ajustar los valores de los resistores para configurar la ganancia deseada.
🔌 Amplificadores Invertidos y Otras Aplicaciones del Op-Amp
El amplificador inverso es una variación del amplificador no inverso, donde la entrada se toma en la entrada inverting y hay una retroalimentación desde la salida a través de un resistor. Este diseño no solo amplifica la señal de entrada sino que también la invierte, con una ganancia dada por -R2/R1. La negatividad de la ganancia indica la inversión de la señal. Además de los amplificadores inverso y no inverso, los Op-Amps pueden utilizarse en aplicaciones como amplificadores de suma de voltaje, amplificadores integradores y diferenciales. Se espera que en futuras entregas se profundice en estas y otras aplicaciones prácticas de los Op-Amps.
Mindmap
Keywords
💡Amplificador
💡Op-amp
💡Entrada no invirtiendo
💡Entrada invirtiendo
💡Ganancia
💡Saturación
💡Buffer de voltaje
💡Amplificador no invirtiendo
💡Amplificador invirtiendo
💡Regla de oro del op-amp
Highlights
Op-amps are basic building blocks of analog electronic circuits, combining operational and amplification functions.
An amplifier increases the strength of an electrical signal, essential for processing, transmitting, or driving output devices.
Operational amplifiers were developed to perform various mathematical operations with minimal adjustments.
Op-amps can be built from discrete components or as integrated circuits, simplifying the design process.
Op-amps are symbolized by a simple triangle shape in circuit diagrams, representing their internal components.
An op-amp has two input terminals and one output terminal, with specific roles for each.
The gain of an op-amp is a critical parameter, representing how much larger the output voltage will be compared to the input voltage difference.
Op-amps can be used as voltage comparators, with the output saturating at the power supply voltage limit.
Adjusting the inverting input voltage allows for comparison with the input signal, creating a square wave output.
Op-amps have three golden rules that simplify their behavior prediction in different configurations.
The voltage buffer application of op-amps ensures the output voltage equals the input voltage without disturbing the source.
Non-inverting amplifiers use op-amps to amplify and maintain the phase of the input signal.
Inverting amplifiers invert and amplify the input signal, with gain determined by the feedback resistor.
The golden rules of op-amps include infinite open-loop gain, zero input current, and output adjustment to eliminate input voltage difference.
Upcoming episodes will cover more applications like voltage summing amplifiers, integrating amplifiers, and differentiating amplifiers.
Transcripts
as well as resistors capacitors diodes
and transistors op amps are one of the
basic building blocks of analog
electronic circuits
so what is an op-amp OP comes from
operational and amp comes from amplifier
an amplifier is an electronic circuit
that increases the strength or magnitude
of an electrical signal
it takes a weak input signal and makes
it larger producing a more powerful
output signal
many electronic signals are weak and
need to be strengthened before they can
be processed transmitted or used to
drive output devices
consider an audio system with a
microphone and a speaker
the microphone converts voice into an
electric signal and the speaker converts
that signal back into voice the issue is
that the microphone's output signal is
weak and not strong enough to drive the
speaker directly
to make the signal strong enough we need
to amplify it that's where the amplifier
comes in
the primary role of an amplifier is to
increase the voltage of the input signal
without significantly distorting its
quality
there are different types of amplifiers
amplifiers are crucial in ensuring that
weak signals become powerful enough to
drive output devices effectively
so what is special about operational
amplifiers
long before the Advent of digital
electronic technology computers were
built to electronically perform
calculations by employing voltages and
currents to represent numerical
quantities for example imagine we have
three water containers with different
temperatures we need to get the average
temperature of these three temperatures
automatically in real time
how can we make such a system we can
place a temperature sensor in each
container the output voltage of each
sensor is proportional to the
temperature of each room's temperature
but how can we get the average of these
three voltages
for that we need to design a special
circuit it should be able to give the
average of these three inputs
and then we can determine the average
temperature using the output voltage
this is an analog computer that computes
the average of its input here is another
example an analog computer that computes
the difference between two sensor
signals
likewise many electronic systems require
performing calculations involving
voltages which include tasks like
finding the voltage difference between
two points adding or summing up voltage
values dividing voltage by a constant
Factor multiplying voltage by a constant
Factor calculating the rate of change of
voltage over time which is the
derivative
and determining the accumulated effect
of voltage over a certain time period
which is the integral
to eliminate the need for Designing
separate circuits for every specific
calculation Engineers pursued a more
adaptable approach they aim to find a
component that could handle various
mathematical operations with minimal
adjustments this Pursuit resulted in the
development of the operational amplifier
intentionally crafted to serve as a
flexible foundational unit for such
calculations the word operational comes
from the idea that these amplifiers were
intended to operate or function in
specific mathematical configurations the
name operational amplifiers implies that
this device can do mathematical
operations and also has the ability to
increase magnitude of an electrical
signal
so op amps are basically a voltage
amplifying device which can be used to
perform various mathematical operations
op amps like any amplifier circuit can
be built from discrete components that
is resistors capacitors and transistors
or even using valves but it is a
laborious and complex task to simplify
the process and make them more
accessible to engineers and designers
manufacturers produce op amps as
integrated circuits or ICS
instead of drawing complex circuit
diagrams op amps are often symbolized by
a simple triangle shape where the
internal components are not individually
represented since many applications of
op-amps require two or more of them
pairs or quartets of op amps are
frequently packaged together
they are very affordable you can buy
dozens of op-amp ics for less than a
dollar
a single op amp has two input Terminals
and one output terminal
one of the inputs is called the
inverting input marked with a negative
or minus sign the other input is called
the non-inverting input marked with a
positive or plus sign
the V plus and V negative power supply
terminals are connected to the positive
and negative terminals of a DC voltage
source respectively these will often be
in the range of positive 5 volts to 15
Volts for the positive Supply and
negative 5 volts to 15 Volts for the
negative Supply this dual Supply
Arrangement allows for the output
voltage to swing both above and below
zero volts
the operational amplifier's output Port
can both sync and Source either a
voltage or a current
when designing a circuit around an
op-amp it is good to be familiar with
its characteristics the primary defining
feature of an op-amp is its gain
as previously discussed op-amps have the
special ability to amplify input
voltages more precisely they amplify the
voltage difference between their two
input terminals
the gain of an op amp represents how
much larger the output voltage will be
compared to the input voltage difference
if the inverting input voltage is V1
non-inverting input voltage is V2 and
the output voltage is V3 then the gain
will be V3 divided by V2 minus V1 this
gain is a critical parameter that
determines the amplification factor of
the op amp
even though the op amps amplify the
difference between its inputs op amps
cannot be used as a differential
amplifier on their own because the
internal gain of an op-amp is really
high the typical real value is about 200
000.
for an example imagine the difference
between the input terminals is just one
millivolts
since the gain is enormous the output
voltage will be theoretically about 200
volts making it unmanageable and
impractical in most scenarios in
practice the op amp can only amplify the
voltage up to the level of its power
supply
however this characteristic can be
effectively utilized in voltage
comparators
here we have an op amp that has a gain
of 200 000 and connected to plus 10
volts and negative 10 volts power supply
let's set the inverting input at zero
volts we are going to compare the
voltage of non-inverting input with the
voltage of inverting input which is 0
volts and give output according to it
the output voltage is equal to the gain
times the input voltage difference
if the voltage difference of inputs is
zero the output is also zero
if the voltage at the non-inverting
input is slightly increased the op amp
attempts to amplify this voltage
difference in such cases the output
theoretically needs to become
substantially higher but there's a
limitation the op amp can only amplify
the voltage up to the level of its power
supply which is 10 volts
when the output reaches this maximum
value it's referred to as saturation
in essence the op amp becomes saturated
when its output hits the supply voltage
limit
like Vice if the voltage of inverting
input is slightly lower than the
non-inverting
the op amp attempts to amplify this
small voltage difference into negative
200 volts but since the power supply
limit is negative 10 volts the output
saturates at the negative Supply voltage
the working summary of op amp voltage
comparator can be shown like this if the
voltage difference of inputs is zero the
output will be zero if the voltage of
non-inverting input is higher than the
inverting input the op amp is saturated
at positive Supply voltage if the
voltage of non-inverting input is lower
than the inverting input the op amp is
saturated at negative Supply voltage
instead of grounding the inverting input
we can make its voltage adjustable like
this so we can set any value in Supply
voltage range then it compare the input
voltage with that value
for example let's set the inverting
input to plus 5 volts if the input is a
sine wave the output will be negative 10
volts for the input values less than 5
volts and the output will be positive 10
volts for the input values more than
positive 5 volts the resulting output is
a square wave
in this configuration the op amp
Compares its input voltages and
saturates the output terminal
accordingly
the uniqueness of op amp extends beyond
their use as comparators
while they can serve as comparators in
specific scenarios their versatility
goes far beyond this role
to make op amps usable as differential
amplifiers in real-world applications
external components such as feedback
resistors are essential to control and
limit the overall gain feedback path
connects the output to the input we call
this closed loop configuration
now we know two op amp configurations
open loop configuration is used to
create comparators the closed loop
configuration is used to configure the
op amp to do the amplification and
mathematical operations before going
further there are few things to explain
to help circuit designers and
enthusiasts rules have been developed in
designing circuits using an op amp based
on their characteristics such rules are
commonly known as the golden rules
as we discussed earlier the open loop
gain is the gain of the op amp without
positive or negative feedback ideally
the open loop gain of an op amp will be
infinite that's the first Golden Rule of
op amp but practically this value is
about 200 000 not Infinity
the second rule states that no current
enters or leaves the op amp inputs which
means the input currents are effectively
zero in simpler terms an ideal op amp
has infinite input impedance which means
it draws no current from the input
sources connected to its inputs although
ideally it is assumed that the input
impedance of an op amp is infinite and
has zero current flow into the inside
real op amps have input leakage currents
from a few Pico amps to a few milliamps
the third rule states that in a circuit
with negative feedback the output
voltage of an op amp will change in
whatever way is necessary to make the
voltage difference between its two
inputs zero in other words an ideal op
amp will adjust its output voltage to
eliminate any voltage difference between
its inverting and non-inverting inputs
these golden rules help in understanding
and analyzing op amp circuits
these rules are based on the ideal
characteristics of op amps and provide
simplified guidelines for predicting
their behavior in different
configurations
keep those rules in mind let's discuss a
few more applications and try to analyze
those using golden rules the next most
basic application of the op amps is the
voltage buffer it's really simple we
just have to connect the output directly
to the inverting input what happens if
we apply one volts to the non-inverting
input
look at the rule number three the op amp
tries to change its output to make sure
whatever is the voltage present in the
non-inverting input is also present in
the inverting input
so the output voltage has also become
one volts
consequently in this configuration the
output voltage becomes equal to the
input voltage as the voltage output is
equal to the voltage input students
might become puzzled and wonder whether
this kind of circuit has any practical
application actually there are many
think we have this kind of voltage
divider and we need to power up some
load if we directly connect the load
like this since the current is flowing
through the load the load will affect
the voltage ratio of the resistance and
change the voltage V1
to avoid this we can use an op amp
buffer to this point and power up our
load according to rule number two no
current flows in or out from the inputs
so the op-amp will not disturb the
voltages V1 and V2 the load's current is
provided by the power supply connected
to the op amp eliminating the Distortion
of the voltage divider's values
another important application of op-amps
is non-inverting amplifier the
configuration of non-inverting amplifier
is like this let's first analyze the
circuit if the VN is applied to the
non-inverting input directly according
to the Golden Rule 3 the voltage of the
inverting input also has to be the same
since the R1 is grounded from one side
the voltage across it is v in and the
voltage across the R2 is equal to V out
minus V in
according to the golden rule 2 no
current flows to the op amp through the
input
so the current flowing through the R1
and R2 is equal
that current can be written as voltage
across each resistor divided by the
resistance like this now we can
rearrange the equation and calculate the
V out
the gain of this non-inverting amplifier
is R1 plus R2 divided by R1
we can adjust the values of R1 and R2 to
set the gain of this non-inverting
amplifier as needed
if the input is a sine wave then the
output of the non-inverting input will
be like this
input is Amplified according to the gain
and it's not inverted the word invert
will be more clear to you in our next
example
our final example for this episode is
the inverting amplifier it's very close
to our previous example but there are
few differences in an inverting
amplifier the input is taken to the
inverting input through a resistor R1 a
feedback path is provided from the
output via the resistor R2 to the
inverting input look closely for ease of
representation inverting and
non-inverting inputs are swapped here
let's analyze the circuit since the
non-inverting input is connected to
ground the voltage of non-inverting
input is zero volts according to the
Golden Rule 3 the voltage of the
inverting input also has to be the same
so the voltage of inverting input is
also become 0 volts
the voltage across R1 is 0 minus V in
and the voltage across R2 is V out minus
zero according to the golden rule 2 no
current flows to the op amp through the
input so the current flowing through the
R1 and R2 is equal that current can be
written as voltage across each resistor
divided by the resistance now we can
rearrange the equation and calculate the
V out the gain of this inverting
amplifier is minus R2 divided by R1 the
negative sign is very important it
indicates that the input is inverted so
this amplifier not only amplify the
input but also inverts it we can adjust
the values of R1 and R2 to set the gain
of this inverting amplifier as needed
if the input is a sine wave then the
output of the inverting amplifier will
be like this
input is Amplified according to the gain
but it's inverted
in this episode we've covered the
fundamental applications of op-amps
including the voltage comparator voltage
buffer non-inverting amplifier and
inverting amplifier in our upcoming
episode we'll delve into more practical
applications such as voltage summing
amplifiers integrating amplifiers and
differentiating amplifiers if you have
any questions feel free to leave them in
the comments below your feedback is
greatly appreciated and motivates us
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