The LM741 Datasheet: A General-Purpose Operational Amplifier

Common symbol for the LM741 op amp

LM741 schematic symbol

Among common electronic components, the operational amplifier, or op amp, stands out as one of the most often implemented parts and one of the simplest to utilize. Typically, op amps are used as comparators or amplifiers and can be used as voltage sources for other devices or circuits. By far, the most commonly used op amp is the LM741, which is a general-purpose amplifier with two inputs—one non-inverting and the other inverting—and a single output. Notable characteristics are the large input impedance between the inputs and low output impedance. 

Let’s investigate this component further using the LM741 datasheet.

Uses and Applications for the LM741 Op Amp

The LM741 op amp can be utilized in a wide variety of ways; however, it is most often applied as listed below.

Common Applications for the LM741 Op Amp

  • Comparators
  • Multivibrators
  • DC Amplifiers
  • Summing Amplifiers
  • Integrators
  • Differentiators
  • Active Filters

As the list above shows, the device is often used for dual input applications; however, the LM741 can also be implemented as a single input element by tying one of the inputs to ground. Let’s take a look at how the LM741 functions. 

Making the Best Use of the LM741 Datasheet

The LM741 op amp can be acquired in several different package types such as CDIP, PDIP, and TO-99. However, all packages have eight pins that should be connected, as shown in the table below (from the LM741 datasheet published by Texas Instruments).

 Pin connections for the LM741

Pinout for the LM741 from the LM741 datasheet published by Texas Instruments

As the table indicates, the op amp has two power supply inputs that are at inverse polarity. The LM741 also includes offset nulls for both the inverting and non-inverting inputs.

LM741 Operation

The basic operation of the LM741 is as a comparator. This can be seen by taking a look at the component’s functional diagram, shown below.

Internal operation of the LM741

LM741 functional diagram

As the diagram (from the LM741 datasheet) illustrates, the op amp is an IC comprised of multiple BJTs, as well as other passive components. The layout clearly exhibits duality signal flows, which enables the comparator functionality. For most applications, the LM741 is also used as an amplifier, where the gain is set by an external resistive network.  In the simplest case, two resistors are used: one is connected from ground to the non-inverting input (pin 3) and the other from pin 3 to the output (pin 6).

Electrical Parameters

In the table below, also from the LM741 datasheet, the electrical parameters and ranges are given. 

Electrical specifications for the LM741

LM741 electrical parameters from the LM741 datasheet published by Texas Instruments

Note, the input resistance is typically 2 MΩ. The output resistance, which for ideal modeling is assumed to be 0, is not listed. An important parameter is the slew rate, which shows how quickly the amplifier can respond to input changes. As listed, this is 0.5 V/µs for the LM741, which allows the component to be used as a filter for some applications.

 Alternatives to the LM741

The 741 op amp was originally manufactured by Fairchild as the uA741. Today, many manufacturers—including Texas Instruments, ON Semiconductor, Microchip, and others—make the LM741 (the LM stands for linear monolithic). The uA741 is also still available and is a good substitute for the LM741. 

Designing PCBAs With the LM741

The LM741 datasheet is a valuable resource that includes information about the functionality, operation, landing pattern, and packaging for the device. However, to ensure that your component is represented accurately for manufacturing and in an accepted format, it is best to leverage the advantages of a CAD model such as the one shown below. 

LM741 design images

CAD images for the LM741

The design images above are available from Ultra Librarian (UL), the world’s largest online parts database. In addition to the CAD images for designing your schematic, PCB layout, and ECAD integration, the UL library for the LM741 also includes simulation models for use with PSpice. 

For a commonly used op amp like the LM741, it is best to utilize the CAD model as well as information from the LM741 datasheet during the building process. If you’re looking for CAD models for common components, Ultra Librarian helps by compiling all your sourcing and CAD information in one place, and this data is presented in a format preferred by PCBA manufacturers.  Working with Ultra Librarian sets up your team for success to ensure streamlined and error-free design, production, and sourcing. Register today for free.

UL-Icon.png

The Ultra Librarian Team

Ultra Librarian offers the world’s largest PCB CAD library, putting cutting-edge materials at your fingertips so you can build better products faster—all for free.

Related Posts

If you’re looking for any of our component footprints or models, we have readily available and free options for you and your design team. Search our library for the solution you’ve been looking for.

Free Design Resources

Ultra Librarian is the worlds largest online – and always free – PCB CAD library. Build products better, faster, and more accurately with easy access to vendor-verified symbols, footprints, and 3D models. Register today to start searching the right components for your next design.

Recommended