The LM4558 IC is a monolithic integrated chip from the LM family that consists of two operational amplifiers. Despite being housed in the same packaging, these two operational amplifiers work separately from one another. However, the power rails for both operational amplifiers are the same. The LM4558 is the perfect choice for usage in a variety of applications because the two op-amps have very little noise interference between them.

LM4558 Pin Description

It consists of two operational amplifiers inside a single package.

Operational Amplifier 1

  • Pin2: Positive Input pin
  • Pin3: Negative Input pin
  • Pin1: Output

Operational Amplifier 2

  • Pin5: Positive Input pin
  • Pin6: Negative input pin
  • Pin7: Output pin

Pin8 and 4 are voltage supply pins. Connect these pins to voltage supply and ground.

LM4558 Features

It offers the following attributes:

  • It offers single supply operation in the +5.0 V to +15 V range, and dual supply operation in the +15V to -15V range.
  • This device is resistant to latch-up.
  • External frequency adjustment is not required because of internal compensation.
  • It uses extremely little power, making it appropriate for a wide range of applications.
  • gives the amplifiers matching phase and gain.
  • 200 mW is the total power dissipation.
  • At the input, it has low noise transistors.
  • It continuously guards against short circuits.
  • 80 dB is the Common-Mode Rejection Ratio.
  • The IC can function between 0 and 70 degrees Celsius.

Where to use LM4558?

A broad range of differential and common-mode input voltages are available for the LM4558 IC. Furthermore, it offers a latch-up-free operation. Frequency correction does not require the connection of external components. It operates steadily thanks to an integrated frequency correction. This gadget is highly suited for voltage follower applications and amplification operations thanks to these qualities.

How to use LM4558?

The two op-amps inside the chip can perform two different functions at the same time. As mentioned in the above section, this dual amplifier IC is well suited for voltage following applications. Therefore, we will explain this circuit to understand its working.

Voltage Follower Circuit Example

Amplification has nothing to do with a voltage follower. It outputs the input value exactly as it is, much like a buffer. The output load will draw more current if it has a low resistance. This is when an operational amplifier has a benefit.

They offer high impedance, which results in the load drawing very little current. They do not load down the source attached to the input pin because of their high impedance. The output pin generates the same input value since the inverting input is linked directly to it without a resistor in between.

LM4558 Applications

This versatile IC is useful in many applications. Few of them are:

  • Incorporates, differentiates, sums, and other mathematical operations.
  • It offers relatively little distortion and is used in phase shift oscillators and sine wave oscillator circuits.
  • Its uses include instrumentation, peak detectors, multivibrators, and signal processing and filtering.

2D Diagram

It is found in 8 pin SOP and 8 pin DIP-packages. The figure shows the two-dimensional diagram of the 8-pin DIP package. The dimensions are in inches. The values in brackets are in millimeters.


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