The 8 Most Commonly Used Integrated Circuits (and Where They're Used)
Some integrated circuits are so useful and reliable that they've been a fixture in nearly every electronics workshop for decades. Knowing these "classics" makes it easier both to understand existing circuits and to quickly pick the right part for your own design. Here are the 8 most commonly used ICs and their typical applications.
Timing and analog
1. NE555 — timer
Perhaps the most popular IC of all time. Used to generate delays, timing, oscillation and PWM; a staple of first projects. Supply: NE555P offers.
2. LM358 — dual op-amp
A low-cost dual operational amplifier that can run from a single supply. It turns up everywhere in signal amplification, filtering and sensor interfaces. Supply: LM358 offers.
3. LM393 — comparator
Compares two voltages and produces a digital output; the basis of threshold detection and simple sensor-triggering circuits. Supply: LM393 offers.
Power management
4. LM7805 — 5 V linear regulator
The classic regulator that steps a higher input voltage down to a steady 5 V. Used in countless circuits to provide a clean supply. Supply: LM7805 offers.
5. LM317 — adjustable regulator
A flexible linear regulator whose output voltage you set with two resistors. Preferred for variable supplies and simple power sources. Supply: LM317 offers.
Digital and control
6. 74HC595 — shift register
Lets you control many outputs from just a few pins; it "expands" microcontroller pins for driving LED arrays and displays. Supply: 74HC595 offers.
7. ATmega328P — microcontroller
The chip at the heart of the popular Arduino boards. It reads sensors, controls outputs and runs your program. Supply: ATmega328P offers.
8. L298N — dual motor driver
A power bridge that drives DC and stepper motors with direction and speed control. A classic of robotics projects. Supply: L298N offers.
Summary table
| IC | Function | Typical use |
|---|---|---|
| NE555 | Timer/oscillator | Delay, PWM, tone generation |
| LM358 | Dual op-amp | Signal amplification, filtering |
| LM393 | Comparator | Threshold detection |
| LM7805 | 5 V regulator | Fixed supply |
| LM317 | Adjustable regulator | Variable supply |
| 74HC595 | Shift register | Pin expansion |
| ATmega328P | Microcontroller | Project brain |
| L298N | Motor driver | DC/stepper motor |
Choosing the right IC
Many ICs perform the same function; the differences usually come down to supply voltage, package type, speed and temperature grade. When choosing one, confirm the supply range and package from the datasheet, and remember that the same part comes with different suffixes (for example DIP vs. SMD). Seeing the same MPN's price and stock across different suppliers makes the sourcing decision easier.
Why are these ICs still indispensable?
It's no accident these classics have survived for decades. They're all cheap, widely available and sourced from multiple manufacturers — which means supply security. Their datasheets and application examples are mature, and the internet is full of circuits and sample code built around them. Most are also offered across a wide supply range and in several packages, so they suit both hobby and industrial projects. Newer, more advanced ICs keep appearing, but for jobs that call for simplicity and reliability these parts remain the first choice.
Projects you can build with these ICs
A few examples: an LED flasher or simple alarm with the NE555; a microphone preamp with the LM358; a clean 5 V supply for a battery-powered circuit with the LM7805; driving dozens of LEDs from a single board with the 74HC595; a remote-controlled robot car with the ATmega328P and L298N. In other words, these eight parts are the building blocks of a huge share of beginner and intermediate projects.
Common mistakes
- Mixing up packages: the DIP and SMD versions of the same chip carry different suffixes; the wrong package won't fit the board.
- No filtering on the regulator: the LM7805/LM317 run unstably without the recommended input/output capacitors.
- Op-amp vs. comparator confusion: they look similar but serve different purposes; a comparator is meant for fast digital comparison.
- Exceeding the current limit: linear regulators and motor drivers heat up; account for power and cooling.
Frequently asked questions
Do these ICs have equivalents?
Most have equivalents from several manufacturers, which brings supply security and price advantages. Comparing equivalents before choosing makes sense.
Is the NE555 still used?
Yes; thanks to its simplicity and reliability it has been produced for decades and is still widely used.
Should I buy DIP or SMD?
DIP is practical for breadboards and learning; SMD is preferred for compact, mass-produced boards.
Conclusion
These 8 ICs are like the "common vocabulary" of electronic design; once you know them you can both decode ready-made circuits and make quick decisions in your own designs. To see all supplier offers and equivalents for an IC, use search, and to review candidates side by side use the comparison tool.