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What is LM358 Operational Amplifier?Detailed description of LM358

What is LM358 Operational Amplifier?Detailed description of LM358

August 15 , 2023 0

This article will introduce about model LM358 from several aspects.Joinwinchips offers a variety of parameters for model LM358, professional one-on-one service, the most detailed and professional product introduction, on-time delivery, the fastest same day shipping.

Today is LM358 op amp , mainly the following aspects:
1, What is LM358?
2, LM358 pin diagram and function
3, LM358 CAD model
4, LM358 principle of operation
5, LM358 characteristics and parameters
6, LM358 classic typical circuit

What is LM358?

The LM358 operational amplifier is a low power dual operational amplifier consisting of two independent high gain internal frequency compensated operational amplifiers specifically designed to be powered from a single supply over a wide voltage range.
The LM358 op amps feature low power consumption, an extended common-mode input voltage range to ground/VEE, and single- or dual-supply operation. It offers several distinct advantages over standard op amp types used in single-supply applications.
The amplifier can be operated from supply voltages as low as 3.0 V or as high as 32 V. The amplifier has a common mode input voltage range that includes the negative supply. The common-mode input range includes a negative supply, eliminating the need for external bias components in many applications. The output voltage range also includes the negative supply voltage.

LM358 Pin Diagram and Function

The LM 358 has a total of 8 pins, each pin has a different individual function, the following is the LM 358 pin diagram and function.
Pin 1 and Pin 8 are the outputs of the comparator.
Pins 2 and 6 are inverting inputs.
Pins 3 and 5 are in-phase inputs.
Pin 4 is the GND terminal.
Pin 8 is VCC+.

Operational Amplifiers:

Operational amplifiers, or simply operational amplifiers, are essentially DC-coupled, high-gain voltage amplification devices, and they are ideally suited for signal conditioning, DC amplification, filtering, and can be used with external feedback components such as capacitors and resistors between their outputs using the input terminals.
An operational amplifier performs different functions depending on its feedback configuration, whether resistive, capacitive, or both, where it can be used as a differential amplifier, integrator, or adder.

In-phase inputs:

The in-phase input of the operational amplifier is marked with a "+" sign on the circuit diagram of the LM358, and the in-phase input is pin 3. A positive voltage is found to be applied to the in-phase input and then it will not change, it will produce a positive swing at the output.
If a changing waveform (e.g. a sine wave) is applied to a non-inverting input (e.g. pin 3 in the LM358) then it will appear at the output in the same way, it is not inverted.

Inverting Inputs:

The inverting input of the operational amplifier is marked with a "-" sign in the schematic of the LM358, and the inverting input is pin 2.
When a positive voltage is applied to the inverting input, a negative voltage swing will result. Therefore, applying a sine wave to the inverting input will result in an inverted phase at the output.

LM358 CAD Model

LM358 Circuit Symbol Diagram

LM358 Package Dimension Diagram

LM358 3D Model

LM358 IC Principle of Operation

Here a Proteus simulation of LM358 has been designed to give you a better understanding of how the LM358 IC works. In this simulation, a small automatic LED switching circuit is designed based on LDR values. The image is shown below:

You can see in the diagram above that I have connected the LDR to the input pin and the LED to the output pin of the LM358.
Now, when LDR is dimmed, the LED will remain off, but when LDR is on, the LED will also be on.
The variable resistor is used for sensitivity purposes and is shown ON in the figure below:

You can see in the picture above that the LED is now on because the LDR is on.

LM358 Characteristic Parameters

Two operational amplifiers in a single package
Wide power supply range
Single supply - 3V to 32V
Dual supply - ±1.5V to ±16V
Input differential voltage range ±32
Low supply current - 700uA
Input common mode voltage range -0.3 to 32
Single supply for reliable operation with two op amps
Junction temperature 150˚C
Operating ambient temperature - 0˚C to 70˚C
Storage temperature range - 65˚C to 150˚C
Solder pin temperature - 260˚C (10 seconds - specified)
Short Circuit Protection Outputs
Available packages: TO-99, CDIP, DSBGA, SOIC, PDIP, DSBGA

LM358 Classic Typical Circuit

1, using the LM358 simple vibration alarm circuit
Using the LM358 vibration alarm circuit design is simple, there are many applications in the family car.
The main application of this circuit is as a burglar alarm for automobiles. In this circuit, a piezoelectric sensor is used as a vibration sensor that must be mounted on the door you must protect.

The LM358 shown in the figure is connected to an inverting Schmitt trigger. Port R1 sets the threshold voltage for the circuit. r1 is used as a feedback resistor.
When the piezoelectric sensor is not activated, the output of the piezoelectric sensor will be low and the output of the IC will be low, so the output of the sensor will be high and activated as a Schmitt trigger. It will then emit a beep.
Even though the vibration has been separated, the buzzer will still beep for some time. This is because, when the LM358 IC is triggered, the inverting input has little effect and the state is not easily inverted. Therefore, it is always good to fix the sensor firmly to a surface, wherever you place it, and to place the sensor near a door handle.
So here this diagram must use a 3V battery as a power source and adjust the R2 register to get the necessary sensitivity.

Infrared Proximity Sensor for LM358

Component List
LM358
10K Ohm Resistor
220 Ohm Resistor
Infrared Emitter LED
Infrared Receiver LED
Color LED
Battery 5V
10K Ohm Variable Resistor

Infrared Lights:

IR LEDs are solid-state lightning devices that emit some form of electromagnetic radiation when energized.IR LEDs emit light longer than visible light. It is important that the IR photodiode used be able to detect the specific wavelength of INFRA RED emitted by the IR LED.

Infrared photodiode:

It is a special type of diode that generates current when exposed to light and it is connected in reverse bias for infrared detection. In the absence of infrared radiation, when light does not fall on it, it has a very high resistance and a small amount of current flows through it called dark current. But when infrared light falls on it, more charge carriers are generated and its resistance decreases and a current begins to flow which is proportional to the intensity of the radiation falling on the photodiode. In a proximity sensor, the photodiode uses this mechanism to generate an electrical signal.

Principle of operation:

The principle followed by the proximity sensor is very simple. an IR LED and a photodiode are connected in parallel with each other and are used as transmitter and receiver. The photodiode is connected with reverse bias. When an obstacle appears in front of the emitter ray, the emitter ray is the IR LED emitter and when that light is reflected back, it is intercepted by the photodiode which acts as the receiver. The reflected light lowers the resistance of the photodiode, thus creating large charge carriers and generating an electrical signal.

This signal is actually a voltage across a 10k resistor, which is a potentiometer, and we can adjust this voltage by adjusting this voltage over varying distances. It is fed directly to the in-phase end of the operational amplifier. The function of the op-amp is to compare the two inputs given to it on pin 2 and pin 3.

The signal from the photodiode is supplied to the in-phase pin (pin 3) connected to a 10k resistor and the threshold voltage from the potentiometer to the adjustable inverting pin (pin 2). If the voltage on the non-inverting pin 2 is greater than the voltage on the inverting pin, it indicates that the light is not falling on the photodiode and the op-amp output is high, otherwise the output is low.

The digital output is either high or low. Obstacle avoidance robots or line following robots use the digital output signal from the proximity sensor to stop the robot's motion or change the robot's direction. Once the obstacle is close enough, the signal can be fed through the H-bridge circuitry directly to the input pins of the motors to drive them.

The analog output is a continuous range of values from zero to some finite value. Motor drivers or other switching devices cannot use analog signals directly. First, they need to be processed by a microcontroller and converted to digital form by an ADC and some coding. This form of output requires an additional microcontroller, but eliminates the need for operational amplifiers.

The mode of operation of the comparator is simple:

Vout = Vcc if Vin > Vref.

The reference voltage is set at pin 2, and if Vin < Vref, Vout = 0, since we ground the pin.

It is worth noting that at this point the output voltage will be approximately equal to the supply voltage Vout~Vcc.

Given these circumstances, our connection of the IR receiver output to a non-inverting input (positive) means that we are connecting the IR receiver to the LM-358's input pin 2. Initially, we said that when the photodiode is not trapping the IR radiation, we will have a

voltage output of about 0.56 V. This means that we will have a voltage output of about 0.56 V when the photodiode is not trapping the IR radiation.

Therefore, we must first give Vref a voltage higher than 0.56 V. Here we will use a potentiometer to set a value higher than 0.56 V to pin Vref. In this case, in state 0, we have Vin < Vref and Vout = 0, so the LED will be off.

When the receiver will capture the radiation, it will allow a higher current to pass, which will exceed Vref and we will have Vin > Vref and Vout = Vcc, about 9V.

Other Applications

Sensor Amplifiers
Conventional operational amplifier circuits
Integrators, differentiators, adders, additions, voltage followers, etc., of
DC gain modules, digital multimeters, oscilloscopes
Comparators (loop control and regulation)
Active filters
General purpose signal conditioning and amplification
4 to 20mA Current Loop Transmitters