Home Blog~~LM358 vs. LM393: Learn about the LM358 op amp and the differences between op amps and comparators~~

~~on April 29th~~ ~~906~~

LM358 vs. LM393: Learn about the LM358 op amp and the differences between op amps and comparators

Overview of LM358 Operational Amplifier

The LM358 is a low power dual operational amplifier consisting of two independent high gain internal frequency compensated operational amplifiers. It is designed for single-supply operation over a wide voltage range. In addition, it features low power consumption, an extended common-mode input voltage range to ground/VEE, and single- or dual-supply operation.

Catalog

1. Overview of LM358 Operational Amplifier

2. Features of LM358 Operational Amplifier

3. Symbol, Footprint, and Pin Configuration of LM358

4. Internal Structure of LM358 Chip

5. Working Principle of LM358 Operational Amplifier

6. What Is the Difference Between LM393 and LM358?

7. How to Use the LM358 Chip?

8. What Are the Applications of LM358 Operational Amplifier?

It offers several distinct advantages over standard op amp types used in single-supply applications. The amplifier can operate from supply voltages as low as 3.0 V or as high as 32 V. The amplifier can be operated from a single supply. Its common-mode input range includes negative supplies, so it eliminates the need for external bias components in many applications. The LM358 is available in an SOP-8 package and is widely used in industrial control, audio amplifiers, DC gain, and all conventional operational amplifier circuits.

Replacements and Equivalents

• CA258

• HA17904PS

• LM358A

• LM358E

• LM358P

• LM358W

Features of LM358 Operational Amplifier

• Its lower input bias current and bias voltage help improve performance and accuracy.

• The LM358 has a high input impedance, making it less susceptible to external signal sources.

• LM358 can operate on a single power supply, which is very convenient for some portable devices and battery-powered applications. Not only does this reduce its power requirements, it reduces the cost and complexity of the device.

• The LM358 is a low-power operational amplifier suitable for battery-powered applications requiring long-term operation.

• The input of the LM358 allows a wide common-mode voltage range, making it ideal for applications that need to handle signals of different levels.

• It integrates two independent operational amplifiers, which makes it suitable for a variety of applications such as amplification, filtering, and comparison.

Symbol, Footprint, and Pin Configuration of LM358

The symbol, footprint, and pin configuration of LM358 are shown below.

LM358 has eight pins, with the output, inverting input, and non-inverting input arranged from top to bottom on the left side. The fourth pin serves as the negative power supply in dual power supply mode and as the ground power supply in single power supply mode. On the right side, the four pins include the non-inverting input terminal, inverting input terminal, output terminal, and positive power supply, arranged from bottom to top.

Internal Structure of LM358 Chip

The internal structure of the LM358 chip includes an output stage, a common mode input stage, a differential mode input stage, two operational amplifiers, etc.

Output stage: It consists of an output stage amplifier and a common pole amplifier, which can achieve voltage amplification and output drive.

Common mode input stage: It consists of a differential amplifier and an operational amplifier to achieve common mode input.

Differential mode input stage: The differential mode input stage consists of a differential amplifier and a common pole amplifier, which can realize differential input.

Operational amplifier: Both operational amplifiers have the same internal structure, each amplifier contains an output stage, a differential mode input stage, and a common mode input stage.

Working Principle of LM358 Operational Amplifier

LM358 is a dual op amp integrated circuit consisting of a differential amplifier and a single-ended amplifier for voltage following function. In a differential amplifier, a differential input circuit is formed between the non-inverting input (IN+) and the inverting input (IN-). When the voltage of IN+ is higher than IN-, the output is positive; when the voltage of IN+ is lower than IN-, the output is negative. Therefore, the LM358 is particularly suitable for comparison circuits.

In a single-ended amplifier, it amplifies the input signal to a level similar to the supply voltage and outputs it. At the same time, it makes the output signal follow the supply voltage, which means it can be used in control circuits.

What Is the Difference Between LM393 and LM358?

LM393 is a dual voltage comparator and LM358 is a dual operational amplifier. They differ in the following aspects.

LM393 is a dual voltage comparator used to compare two input signals and output a corresponding high or low level. The LM358 is a dual operational amplifier. An operational amplifier is a circuit commonly used to amplify input signals. Unlike a comparator, the output of an op amp can vary continuously over a wide range and is not limited to high or low levels.

The op amp output stage generally uses a push-pull circuit to achieve bipolar output. However, most comparator output stages use an open-collector structure to achieve unipolar output.

The LM393 comparator has a fast flipping speed, approximately on the order of ns. The flipping speed of LM358 operational amplifiers is generally on the order of us (except for special high-speed operational amplifiers).

The op amp can be connected to a negative feedback circuit, but the comparator cannot use negative feedback. Although the comparator also has two input terminals, non-inverting and inverting, there is no phase compensation circuit inside, so if negative feedback is connected, the circuit may not work stably. It has no phase compensation circuit inside, which is why the comparator is faster than the op amp.

How to Use the LM358 Chip?

First, we need to connect the chip to the circuit correctly. Typically, the LM358 chip has 8 pins, including the non-inverting and inverting input pins of the two operational amplifiers, as well as the output and power supply pins. Before connecting the chip to the circuit, we should carefully read the chip's data sheet to understand the function of each pin and the correct wiring method. In addition, we should also pay attention to the power supply voltage and operating temperature range required by the chip to ensure its normal operation.

What Are the Applications of LM358 Operational Amplifier?

• Audio amplification: LM358 chip can be used for audio amplification. For example, in a sound system, it amplifies weak audio signals to a sufficient level to make the sound from the speakers clearer.

• Feedback control systems: LM358 can be used to form feedback control loops. It achieves precise control of system parameters by measuring the output signal and comparing it with a reference signal. It is usually used in fields such as automatic control systems, regulated power supplies, and motor drives.

• Voltage comparator: LM358 has a dual op-amp structure, one of which can be used as a voltage comparator. By setting the threshold voltage, it can implement functions such as voltage comparison, switch control, and trigger.

• Sensor interface: The LM358 can be used as a signal amplifier for sensor interface circuits to amplify weak sensor signals to a suitable range for subsequent data processing and analysis. It is used in a wide range of application scenarios, including pressure sensors, light sensors, and temperature sensors.

• Voltage following: It can also be used in voltage following circuits. It implements functions such as tracking and controlling voltage changes by amplifying the input voltage and outputting the corresponding voltage signal.

• Signal processing: LM358 can be used as a key component in analog signal processing circuits to amplify, filter, and enhance input signals. For example, we use LM358 for audio amplification to obtain clear sound quality.

Frequently Asked Questions [FAQ]

1. What is LM358 sensor?

In electronics, this sensor is analogous to human's visionary senses which can be used to detect an obstacle which is one of its common applications. In robotics, a group of such modules are used so that a robot can follow a line pattern. This circuit is made using the following: 1. LM358 IC.

2. What is LM358 used for?

LM358 can be used as transducer amplifier, DC gain block etc. It has large dc voltage gain of 100dB. This IC can be operated on wide range of power supply from 3V to 32V for single power supply or from ±1.5V to ±16V for dual power supply and it also support large output voltage swing.

3. Is LM358 a good op-amp?

There are much better opamps available for sensible prices, and for the most part there's no good reason to use an LM358 in any audio circuit. However, this opamp has some useful characteristics, and it's very low power, which may well be just what you need.

4. What are the advantages of LM358?

These amplifiers have several distinct advantages over standard operational amplifier types in single supply applications. They can operate at supply voltages as low as 3.0 V or as high as 32 V, with quiescent currents about one−fifth of those associated with the MC1741 (on a per amplifier basis).

5. What is LM358 in Arduino?

LM358 is a type of operational amplifier. It consists of two independent, high-gain, frequency-compensated operational amplifiers designed to operate from a single supply over a wide range of voltages.

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