LM324N quad op-amp: specs and pinout
A Texas Instruments LM324 quad operational amplifier in a 14-pin PDIP package (N). Four amplifiers share one supply and work from a single supply or a split supply. It is a general-purpose part, not a rail-to-rail one.
Specs
| Spec | Value | Source |
|---|---|---|
| Supply voltage (VCC) | 3 V to 30 V (LM324, LM324A, LM324K, LM324KA) | source Recommended Operating Conditions |
| Amplifiers per package | 4 | source Description |
| Common-mode input range | 0 V to VCC minus 2 V | source Recommended Operating Conditions |
| Supply current (four amplifiers) | 1.4 mA typical, 3 mA maximum | source Electrical Characteristics |
| Input offset voltage (max, 25 C) | 7 mV (LM324 and LM324K) | source Device comparison table, Section 1 |
| Operating ambient temperature | 0 C to 70 C (LM324) | source Device comparison table, Section 1 |
| Package | N (PDIP, 14), 19.3 mm x 9.4 mm | source Device Information |
Power
| Value | Source | |
|---|---|---|
| Supply | 3 V to 30 V single supply (or split supply) | source Recommended Operating Conditions; Electrical Characteristics |
| Current | 1.4 mA typical, 3 mA max for all four amplifiers | source Recommended Operating Conditions; Electrical Characteristics |
Pinout
This is a bare chip, not a module. The pinout is the 14-pin package pinout from the Texas Instruments datasheet; the LM324N part number matches TI's orderable N-package part.
| Pin | Function | Voltage | Notes | Source |
|---|---|---|---|---|
| 1OUT (1) | Amplifier 1 output | source Figure 5-1, Pin Functions | ||
| 1IN- (2) | Amplifier 1 inverting input | source Figure 5-1, Pin Functions | ||
| 1IN+ (3) | Amplifier 1 non-inverting input | source Figure 5-1, Pin Functions | ||
| VCC+ (4) | Positive supply | 3 V to 30 V | source Figure 5-1, Pin Functions | |
| 2IN+ (5) | Amplifier 2 non-inverting input | source Figure 5-1, Pin Functions | ||
| 2IN- (6) | Amplifier 2 inverting input | source Figure 5-1, Pin Functions | ||
| 2OUT (7) | Amplifier 2 output | source Figure 5-1, Pin Functions | ||
| 3OUT (8) | Amplifier 3 output | source Figure 5-1, Pin Functions | ||
| 3IN- (9) | Amplifier 3 inverting input | source Figure 5-1, Pin Functions | ||
| 3IN+ (10) | Amplifier 3 non-inverting input | source Figure 5-1, Pin Functions | ||
| VCC- (11) | Negative supply or ground (single supply) | 0 V | source Figure 5-1, Pin Functions | |
| 4IN+ (12) | Amplifier 4 non-inverting input | source Figure 5-1, Pin Functions | ||
| 4IN- (13) | Amplifier 4 inverting input | source Figure 5-1, Pin Functions | ||
| 4OUT (14) | Amplifier 4 output | source Figure 5-1, Pin Functions |
Build with it
Project ideas for the LM324N quad op-amp. Each link opens Soldr with the prompt filled in; Soldr assigns the pins, checks power and shows how to wire every part.
- Four-step light level bar: Four comparators each light one LED as an LDR divider crosses a resistor-ladder level. On the Uno's 5 V, keep every input below about 3 V (VCC minus 2 V). Learning project.
- Potentiometer voltage follower with indicator LED: One amplifier as a unity-gain buffer shows how a high-impedance source can drive a load. On a 5 V supply the input must stay at or below about 3 V (VCC minus 2 V), so do not wire the potentiometer across the full 5 V: put a resistor of about 6.8 k from the 5 V pin to the top of the 10 k potentiometer (two resistors in series from the pack if needed) so the wiper tops out near 3 V. Add a 100 nF capacitor across the supply. Learning project.
- A gain-of-four amplifier with an LM324 that scales a small adjustable voltage so an Arduino Uno can read it on an analog pin: A feedback resistor about three times the ground resistor (from the pack) gives a gain near four. The input comes from the potentiometer through a divider that keeps it at or below about 0.75 V, so the output stays at or below 3 V, inside VCC minus 2 V on the Uno's 5 V, and the Uno analog pin sees well under 5 V. Add 100 nF across the supply. Learning project.
Common mistakes
- Driving inputs up to the supply rail: the common-mode input range ends at VCC minus 2 V (source: link, Recommended Operating Conditions)
- Running it from 3.3 V with inputs near 3.3 V: with a 3.3 V supply, inputs must stay below about 1.3 V (source: link, Recommended Operating Conditions)
- Shorting an output to VCC: the datasheet warns this can cause excessive heating and eventual destruction (source: link, Absolute Maximum Ratings notes)
Not covered by the official source
- Datasheet covers many variants; LM324 non-B column values used and temperature range 0 C to 70 C taken from the comparison table.
Sources
- link (LM124/LM224/LM324/LM2902 datasheet SLOS066AE, Aug 1975, revised Sept 2025, Texas Instruments). LM324N is TI's part number for the PDIP-14 package.