LM324NE3 - Quad General-Purpose Op Amp, 14-PDIP | Texas Instruments
MPN: LM324NE3 ✗ End of LifeLM324NE3 Overview
An operational amplifier (op amp) is a high-gain differential amplifier whose output voltage is controlled by the difference between its two inputs. The LM324 family sits in the general-purpose tier of the amplifier hierarchy: op amp -> voltage-feedback amplifier -> integrated amplifier IC -> analog signal chain building block. Because the LM324 is designed for single-supply operation, it is the classic choice for battery-powered, portable, and low-cost instrumentation where a ground-referenced signal sits near the bottom rail.
Key features of the LM324 family include wide supply range operation, low quiescent current typical of the class, differential inputs with common-mode range extending close to the supply rails, and output swing capability from the negative rail to roughly 1.5 V below the positive rail on a single supply. The modern B and BA device variants extend the supply range to 3 V to 36 V and tighten input offset voltage to 3 mV (B) and 2 mV (BA), and are documented by the manufacturer as drop-in replacements for the original LM324, LM224 and LM2902 versions.
The LM324NE3 specifically is the older non-B revision of the LM324N family supplied in a through-hole PDIP-14 package. Texas Instruments lists this part number as no longer in production, so new designs should target the current LM324N, LM324AN or LM324BN ordering codes in the same 14-pin through-hole footprint, or a surface-mount equivalent where board space is constrained.
Typical applications include DC signal conditioning, low-level current-voltage conversion, sensor front-end amplification, audio preamplifier stages, battery-powered instrumentation, relay and comparator-style threshold stages, and general control loop error amplifiers. Because it is a bipolar-input amplifier, it is best suited to DC and low-frequency signal chains rather than wideband or high-speed applications.
When designing with this part, keep in mind that the classic LM324 output swing does not reach the positive rail, so headroom of roughly 1.5 V is required above the desired output level. Decoupling of 0.1 uF close to the supply pins plus a bulk capacitor near the source of power is standard practice. Also note that the LM324 does not include input overvoltage or short-circuit protection, so rail-to-rail input conditions must be avoided in new designs.
This page brings together the manufacturer lifecycle status, package and pinout details, drop-in replacement paths within the same 14-PDIP footprint, and practical design guidance that is not consolidated anywhere in a single manufacturer document, helping engineers qualify a supply-chain-safe alternative for legacy designs.
Drop-in alternatives for LM324NE3 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with LM324NE3 (same form factor and footprint) — differing in Package, Amplifier Type, Supply Configuration, Mounting Type, Number of Amplifiers.
LM324N
✅ Drop-In ⚠️ Specs UnverifiedContact for price
View Datasheet →LM324AN
✅ Drop-In ⚠️ Specs UnverifiedContact for price
View Datasheet →LM324BN
✅ Drop-In📋 Reference alternative (not in catalog)
LM324IN
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
LM324DR
✅ Drop-In ⚠️ Specs UnverifiedContact for price
View Datasheet →LM324NE3 Maximum Ratings & Electrical Characteristics
| Number of Amplifiers | 4 |
| Amplifier Type | Quad, General Purpose, Voltage Feedback, Internally Frequency Compensated |
| Supply Voltage Range (B, BA versions) | 3 V to 36 V |
| Supply Topology | Single supply or split (dual) supply |
| Input Offset Voltage (B version) | 3 mV |
| Input Offset Voltage (BA version) | +/-2 mV |
| Package | 14-PDIP (N) |
| Mounting Type | Through-hole |
| Number of Pins | 14 |
| Product Type | Standard (General Purpose) Amplifier |
| Lifecycle Status | No longer in production (per manufacturer part-details page) |
| B Version Drop-In Compatibility | Drop-in replacement for all versions of LM224, LM324 and LM2902 |
| RoHS Status | Compliant |
| Lead-Free / Pbfree | Yes |
LM324NE3 Pin Configuration
| Pin 1 | OUT1 — Amplifier 1 output |
| Pin 2 | -IN1 — Amplifier 1 inverting input |
| Pin 3 | +IN1 — Amplifier 1 non-inverting input |
| Pin 4 | V+ — Positive supply voltage |
| Pin 5 | +IN2 — Amplifier 2 non-inverting input |
| Pin 6 | -IN2 — Amplifier 2 inverting input |
| Pin 7 | OUT2 — Amplifier 2 output |
| Pin 8 | OUT3 — Amplifier 3 output |
| Pin 9 | -IN3 — Amplifier 3 inverting input |
| Pin 10 | +IN3 — Amplifier 3 non-inverting input |
| Pin 11 | V- — Negative supply voltage |
| Pin 12 | +IN4 — Amplifier 4 non-inverting input |
| Pin 13 | -IN4 — Amplifier 4 inverting input |
| Pin 14 | OUT4 — Amplifier 4 output |
Typical Applications
LM324NE3 is suitable for 6 applications: DC Signal Conditioning and Instrumentation Amplifier Front End, 5V Battery-Powered Sensor Interface, Audio Preamplifier and Mixer Stage, Relay Drive and Threshold Detection, Power Supply Feedback and Error Amplifier, Educational and Prototyping Universal Op Amp Board.
DC Signal Conditioning and Instrumentation Amplifier Front End
The LM324NE3 is a natural fit for low-level DC conditioning because each of its four amplifiers is independent and internally frequency compensated, so a single 14-pin part can build a complete multi-stage analog front end. A common arrangement uses one amplifier as a non-inverting gain stage with the gain set by a feedback divider, a second stage as an inverting summing amplifier, and the remaining two channels driving a reference buffer and a guard buffer. Because the amplifiers are internally compensated, the loop stays stable at unity gain without external compensation components, which shortens bring-up time on the bench. On a 5V single-supply board, keep the output swing below the top rail and check the input common-mode range at end-of-discharge voltage before finalising the gain schedule.
Recommended
5V Battery-Powered Sensor Interface
Single-supply operation across a wide voltage range is the defining reason the LM324 family remains standard in battery-powered sensor interfaces, and the LM324NE3 applies that same architecture in a through-hole package that is easy to hand-solder for prototypes and field service boards. A typical cell or 5V rail drives a resistive sensor bridge whose millivolt-level differential output is amplified by one channel, referenced against the same supply rail by another, then filtered by the remaining two channels before reaching the ADC input. Because the output swing does not reach the positive rail, the usable output range should be planned with roughly 1.5 V of headroom, which matters most when the battery is near discharge. Decouple the supply pins with a local 0.1 uF ceramic plus a local bulk capacitor to keep switching noise out of the measurement.
Recommended
Audio Preamplifier and Mixer Stage
The LM324 family has been a fixture in audio preamplifier and mixing circuits for decades, and the LM324NE3 continues that role in equipment built around through-hole construction, repair kits and educational builds. With four amplifiers in one package, a typical passive-input preamp uses one channel for input gain, a second for tone control, a third as a buffer ahead of the mixer, and the fourth to drive a line-level output. The gain-bandwidth of this class of part comfortably handles audio-band signals, while the large-ish internal compensation capacitors mean it is not the right choice for ultrasonic or wideband audio paths. Keep the signal path grounded to a single star point and place the supply bypass capacitor physically close to pin 4 and pin 11 to avoid injecting supply ripple into the gain stages.
Recommended
Relay Drive and Threshold Detection
When the LM324NE3 is used as a comparator rather than a linear amplifier, the classic arrangement compares a feedback-derived threshold against a sensor input and pulls a logic or relay drive node. Because the part contains four amplifiers, one package can host several independent threshold channels, such as over-temperature, over-voltage and under-voltage monitors in a single industrial control board. Relays and solenoids are inductive loads, so a flyback diode is mandatory across the coil and the relay driver transistor must be kept away from the sensitive analog ground to avoid injected transients corrupting the threshold reference. Setting hysteresis in the feedback network is also recommended, since the bipolar input stage of this amplifier family otherwise shows input voltage noise that can cause chatter near the trip point.
Recommended
Power Supply Feedback and Error Amplifier
In a linear regulator or DC-DC converter control loop, the error amplifier compares the scaled output voltage against a reference and drives the correction element. The LM324NE3 fits this role in laboratory and legacy supply designs where a through-hole quad amplifier provides four error channels in one package, such as main loop, current limit, soft start and auxiliary rail tracking. Because it is an internally compensated voltage-feedback amplifier with a moderate gain-bandwidth, compensation is set entirely by the external compensation network around pins 2 and 6 of each channel, and the loop crossover frequency must stay well below the switching frequency of the converter to keep the design stable. A dedicated wide-band error amplifier gives more phase margin when the switching node is fast and the output capacitor is small, so confirm the loop gain target before locking the bill of materials.
Recommended
Educational and Prototyping Universal Op Amp Board
The LM324NE3 remains a staple in university laboratories, maker kits and breadboard-style prototypes because it is inexpensive, forgiving, and tolerant of wide supply swings, and it is one of the most widely recognised amplifier footprints in the world. A typical teaching board breaks the 14-pin PDIP into four isolated channels with accessible headers, jumpers and a switchable single or split supply so students can compare inverting, non-inverting, summing and comparator configurations without rewiring the chip. Because the device is bipolar-input and internally compensated, students can build working amplifier stages immediately while still learning about input bias current, output swing headroom and common-mode range limits from the datasheet. The through-hole package also makes it easy to replace a failed device with a basic soldering iron, which matters in large teaching labs.
Recommended
Recommended Products Summary
Engineering reference data for LM324NE3 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LM324N | LM324AN | LM324BN | LM324IN | LM324DR |
|---|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | 14-PDIP (N), through-hole | 14-PDIP (N), through-hole - same footprint | 14-PDIP (N), through-hole - same footprint | 14-PDIP (N), through-hole - same footprint | 14-PDIP (N), through-hole - same footprint | SOIC-14 (D), surface mount - same pinout, different footprint |
| Number of Amplifiers | 4 | 4 | 4 | 4 | 4 | 4 |
| Amplifier Type | General purpose, internally frequency compensated, voltage feedback | General purpose, internally frequency compensated | General purpose, internally frequency compensated, A-version | General purpose, internally frequency compensated, B-version | General purpose, internally frequency compensated | General purpose, internally frequency compensated |
| Supply Voltage Range | Single or split supply, wide range; 3 V to 36 V documented for the improved B/BA versions | Wide range single or split supply | Wide range single or split supply | 3 V to 36 V | Wide range single or split supply | Wide range single or split supply |
| Input Offset Voltage | Original LM324 revision, wider tolerance | Original revision tolerance | A-version, tightened tolerance | 3 mV | Original revision tolerance | Original revision tolerance |
| Lifecycle Status | No longer in production | Active | Active | Active | Active | Active |
| Drop-In Status vs LM324NE3 | Reference device | Pin-for-pin identical | Pin-for-pin identical | Documented drop-in replacement for all LM224/LM324/LM2902 versions | Pin-for-pin identical | Same pinout but surface-mount package |
| RoHS / Lead-Free | Compliant, Pbfree | Compliant, Pbfree | Compliant, Pbfree | Compliant, Pbfree | Compliant, Pbfree | Compliant, Pbfree |
| Mounting / Assembly | Through-hole, hand or wave solderable | Through-hole | Through-hole | Through-hole | Through-hole | Surface mount, reflow |
Key Differentiators
- Same 14-pin PDIP footprint as the active ordering codes, so no board change is needed (vs LM324DR)
- Explicitly documented drop-in upgrade path for legacy LM324 sockets (vs LM324BN)
- Improved DC accuracy available in the same socket for precision signal chains (vs LM324AN)
- Through-hole package remains practical for repair, prototyping and small-batch builds (vs LM324DR)
Design Notes
The LM324NE3 has no on-chip supply protection, so treat the supply pins as sensitive. Keep a 0.1 uF ceramic decoupling capacitor physically adjacent to pin 4 (V+) and pin 11 (V-), and add a bulk electrolytic or ceramic near the power entry point. Because the output swing of this amplifier class falls short of the positive rail, budget roughly 1.5 V of headroom above the highest required output level; this is the single most common cause of clipped outputs in 5V single-supply designs. On split supplies, the ground pin of each amplifier is the supply mid-point and must be connected reliably, otherwise input bias current returns flow through signal paths and create offset errors.
Do not use the LM324NE3 as a rail-to-rail comparator for signals that swing to the supply rails: the common-mode input range and output swing both fall short of the rails, so a rail-to-rail input stage will saturate and recover slowly. Also avoid operating near the lower rail on a single supply, because bipolar input bias current multiplied by high source impedance shifts the common-mode point. For designs that must accept 0 V inputs or reach the top rail, migrate to a rail-to-rail quad amplifier rather than attempting to compensate around this device.
The 14-pin PDIP footprint is standard and mechanically compatible with LM324N, LM324AN, LM324BN and LM324IN, so leave the through-hole pads free of copper dams that would hinder rework. Route the two supply pins to a common, low-impedance plane connection and keep analog ground returns from the four channels gathered at a single star point near pin 11 rather than daisy-chained under the package. For production assemblies where the package will be machine-inserted, verify the row spacing and hole diameter against the mechanical drawing in the manufacturer datasheet rather than relying on a generic DIP drawing.
Although the amplifiers are internally frequency compensated for unity gain, stability at higher closed-loop gains depends on the compensation network and the feedback trace. Keep the feedback resistors physically close to the inverting input pins and avoid routing the non-inverting input next to the output to prevent capacitive positive feedback, which shows up as oscillation or rail-to-rail square waves at the output. On boards with long analog traces, terminate with a small resistive divider at the input or add a series resistor with the source impedance to damp the input capacitance.
Compliance Information
RoHS compliance and Pbfree status are indicated by the manufacturer part listing for the LM324 family. REACH, halogen-free and conflict-minerals statements are not published on the part-details pages consulted for this ordering code and are therefore recorded as unknown. This general-purpose amplifier family is not qualified to AEC-Q100.
