What Is the LM324? Quad Op-Amp: Pinout, Specs and Uses
The LM324 is a low-cost IC with four independent operational amplifiers (op-amps) in one package that runs from a single supply (3–32 V). It is the quad sibling of the dual LM358; because its input senses ground, it is ideal for battery-powered circuits. It is used for multi-channel sensor conditioning and active filter banks; its output is not rail-to-rail.
The LM324 is a low-cost IC that packs four independent operational amplifiers (op-amps) into a single 14-pin package and runs from a single supply. It is essentially the quad sibling of the dual LM358 and shares the same electrical character. For the concept, see what is an op-amp.
What is the LM324 used for?
When a circuit needs several amplifier/filter stages, it provides four channels on one chip: multi-channel sensor conditioning, active filter banks, summing/comparison stages. Because its input reaches down to ground (0 V), it is ideal for single-supply and battery-powered systems.
LM324 pinout (DIP-14 / SOIC-14)
| Pin | Function | Pin | Function |
|---|---|---|---|
| 1 | Output 1 | 14 | Output 4 |
| 2 | Input 1− | 13 | Input 4− |
| 3 | Input 1+ | 12 | Input 4+ |
| 4 | V+ (VCC) | 11 | V− / GND |
| 5 | Input 2+ | 10 | Input 3+ |
| 6 | Input 2− | 9 | Input 3− |
| 7 | Output 2 | 8 | Output 3 |
The supply pins 4 (V+) and 11 (V−/GND) are shared by all four op-amps.
Key electrical specifications
| Parameter | Typical value |
|---|---|
| Number of op-amps | 4 (independent) |
| Supply (single) | 3 V – 32 V |
| Supply (dual) | ±1.5 V – ±16 V |
| GBW | ~1.1 MHz |
| Slew rate | ~0.3 V/µs |
| Input common-mode range | includes V− (ground) |
| Output | not rail-to-rail (cannot reach V+) |
LM324 or LM358?
They are from the same family with the same electrical figures. The difference is channel count and package: the LM358 has two op-amps (8 pins), the LM324 has four (14 pins). If your circuit has 3–4 amplifier stages, the LM324 saves both board space and cost.
Limitations
- The output is not rail-to-rail; for full swing choose a part like the MCP6004.
- The class-B output stage causes crossover distortion at the zero crossing → not for hi-fi audio.
- At ~0.3 V/µs it is slow; not suited to high frequency.
LM324 equivalents and alternatives
- LM358: the dual (2 op-amp) version of the same family.
- LM2902: the automotive (AEC-Q100) counterpart of the LM324.
- TL074: quad JFET input, for audio/high impedance.
- MCP6004: quad rail-to-rail, low voltage.
Find it in our catalog
To compare price and stock for the LM324 and its alternatives, use the LM324 search. For gain, use the Op-Amp Gain Calculator.