LM324 is a 14pin IC consisting of four independent operational amplifiers (op-amps) compensated in a single package. Op-amps are high gain electronic voltage amplifier with differential input and, usually, a single-ended output. The output voltage is many times higher than the voltage difference between input terminals of an op-amp.
These op-amps are operated by a single power supply LM324 and need for a dual supply is eliminated. They can be used as amplifiers, comparators, oscillators, rectifiers etc. The conventional op-amp applications can be more easily implemented with LM324.
Pin Description:
| Pin No | Function | Name |
| 1 | Output of 1st comparator | Output 1 |
| 2 | Inverting input of 1st comparator | Input 1- |
| 3 | Non-inverting input of 1st comparator | Input 1+ |
| 4 | Supply voltage; 5V (up to 32V) | Vcc |
| 5 | Non-inverting input of 2nd comparator | Input 2+ |
| 6 | Inverting input of 2nd comparator | Input 2- |
| 7 | Output of 2nd comparator | Output 2 |
| 8 | Output of 3rd comparator | Output 3 |
| 9 | Inverting input of 3rd comparator | Input 3- |
| 10 | Non-inverting input of 3rd comparator | Input 3+ |
| 11 | Ground (0V) | Ground |
| 12 | Non-inverting input of 4th comparator | Input 4+ |
| 13 | Inverting input of 4th comparator | Input 4- |
| 14 | Output of 4th comparator | Output 4 |