LM258 Op Amp : Pin Configuration & Its Working

The LM258 op-amp is a dual op-amp-based integrated circuit. This IC belongs to the ‘LMxx’ family member. Here, the prefix of this IC like ‘LM’ denotes the series of integrated circuits which stands for linear monolithic, invented by National Semiconductor. Linear monolithic refers to the analog components which are incorporated onto a single Si IC.


This LM258 Op Amp is available with two separate internally frequency compensated op-amps with high gain. These inbuilt ICs were specifically designed to work with a single power supply over an extensive range of voltages. This article discusses an overview of LM258 Op-Amp like its pinout, features, specifications, circuit working, advantages, and applications.

What is LM258 Op Amp?

The LM258 op-amp includes two separate op-amps with high gain & internally compensated frequency. This chip operates with a single power supply on different voltage ranges.

This IC also operates with split power supplies & the current drain with less power supply is independent of the magnitude of the voltage supply. This operational amplifier is used in DC gain blocks, transducer amplifiers & conventional op-amp circuits.

LM258 Op Amp
LM258 Op Amp

For instance, the LM258 series operational amplifier can be operated off of the typical +5V power supply which is utilized in digital systems to provide the necessary electronics interface without requiring the extra ±15V power supplies.

In addition, this IC can perform two dissimilar functions at a time in several applications. This IC is very famous so it can be used by engineers & beginners in different electronics projects.

Pin Configuration

The pin configuration of LM258 Op-Amp is shown below. This IC is available with 8-pins where each pin and its functionality are discussed below.

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LM258 Pin Configuration
LM258 Pin Configuration
  • Pin 1(OUT1): This is the o/p pin of the first operational amplifier
  • Pin2 (1IN-): This is the first op-amp’s inverting input
  • Pin3 (1IN+): This is the first op-amp’s non-inverting input
  • Pin4 (GND): Ground pin
  • Pin5 (2IN+): This is the second op-amp’s non inverting input
  • Pin6 (2IN-): This is the second op-amp’s inverting input
  • Pin7 (2OUT): This is the second op-amp’s o/p pin
  • Pin8 (VCC): This is the power supply pin

Packages & Dimensions

The packages and dimensions of LM258 Op-Amp include the following.

  • For SOIC (8) package, its dimension is 4.9X3.9 mm
  • For VSSOP (8) package, its dimension is 3X3 mm
  • For the SO (8) package, its dimension is 5.20 X 5.30 mm
  • For PDIP (8) package, its dimension is 9.81 X 6.35 mm

Features & Specifications

The features & specifications of LM258 Op-Amp include the following.

  • The voltage supply is a wide range
  • It works with a single power supply
  • Two operational amplifiers are operated separately
  • Interference is less noise based in between two op-amps
  • Bandwidth is wide like 1 MHz
  • Gain of DC voltage is large like 100 dB
  • Offset voltage with less input is 2 mV
  • Range of Input common-mode includes GND
  • The voltage supply voltage is equivalent to differential i/p voltage.
  • Internal compensation of frequency
  • Voltage supply ranges from +3.0 V to +32 V
  • Operation of dual voltage supply +16V & -16V
  • Very less current supply drain like 500µA
  • Operating temperature ranges from -25ºC – 85ºC
  • Complete power dissipation is 830mW
  • Power drain is apt for the operation of the battery
  • The pin configuration is similar to the LM258 dual op-amp
  • Op-amps are compensated internally
  • In the linear mode, the input common-mode voltage range includes ground and the output voltage can also swing to ground, even though operated from only a single power supply voltage.
  • The unity gain cross frequency is temperature compensated.
  • The input bias current is also temperature compensated.

The characteristics of the LM258 op-amp are; the i/p common-mode voltage range within the linear mode comprises GND & the o/p voltage can also swing toward the ground, although it is operated by using a single voltage power supply. The cross-frequency unity gain is compensated with temperature and the input bias current is also compensated with temperature.


How to use LM258 Op-Amp?

The low current applications of LM258 op-amp are voltage reference examination, voltage regulators & current generators recognized with op-amps due to the limits of the operational amplifier.

Voltage Reference Circuit with LM258 IC
Voltage Reference Circuit with LM258 IC

The simple voltage reference circuit using LM258 op-amp is shown below. The required components to build this circuit is voltage supply is 10V, Z1=ZPD5.1, RZ=1k, & RL is 10k potentiometer. The main function of the voltage follower circuit is if we require a voltage reference that is equivalent to the Zener diode’s breakdown voltage. Here, the operational amplifier’s less o/p resistance is nothing but the o/p voltage mainly depends on extremely small the load.

Measurements

To build the above circuit diagram, we need to arrange the potentiometer to the maximum. So measure the o/p voltage or Vout & the voltage of the more zen diode (Vz). Evaluate these two values
Next need to measure the least load resistor by setup 80mA current limit. To begin reducing load resistor and check the output voltage.

Let’s describe minim load resistor once output voltage reduces to approximately 90% of its small value. At this point, calculate the o/p current. Evaluate the measured value through the maximum ratings using the op-amp datasheet like o/p current & short circuit o/p current. Again set the current to 20mA after this measurement.

Need to check the dependence of output voltage on the voltage supply. For that, need to set the load resistor to the maximum. To measure output voltage correctly at 10V & 19V because the supply unit cannot exceed to 20V. Find the relative change like ΔVout/ ΔVsupply [mV/V].

Where to Use/Applications

The applications of LM258 dual op-amp include the following.

  • It is used in analog and digital electronics
  • Power Supplies
  • Mobile Chargers
  • Motherboards
  • Personal Computers
  • UPS or Uninterruptible Power Supplies
  • Mathematical operations
  • Amplifiers
  • Voltage Comparators
  • Oscillators
  • Measuring Instruments
  • Active Filters
  • PLCs or Programmable Logic Controllers
  • Amplification & Signal Conditioning
  • Refrigerators, Dryers & Washers
  • Current Loop Transmitters (4 – 20-mA)

Thus, this is all about an overview of the LM258 Op Amp datasheet which includes its pin configuration, features, specifications, circuit, characteristics, and applications. The advantages of LM258 Op-Amp includes; it includes two op-amps, eliminates dual supply requirement and its power drain is appropriate for the operation of the battery. Here is a question for you, what are the disadvantages of LM258 Op-Amp?

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