LM324KN - Quad 14-PDIP General-Purpose Op Amp | Texas Instruments
MPN: LM324KN ✓ ActiveLM324KN Overview
An operational amplifier is an analog signal-conditioning IC that uses feedback to control gain, amplify differential inputs, buffer sensors, and perform general-purpose analog calculations. The LM324 family belongs to the operational-amplifier hierarchy within analog and mixed-signal semiconductors. Its common-mode input range includes ground, making it useful in circuits powered from a positive rail and sensing signals near 0 V.
The four independent channels can perform simultaneous amplification, filtering, buffering, or summing functions while sharing one package. Internal frequency compensation makes the LM324 suitable for general-purpose closed-loop amplifier designs without external compensation networks. Its low 0.8 mA typical supply-current drain helps reduce system power consumption, while the broad supply capability supports industrial and legacy equipment operating from multiple rail voltages.
Common applications include sensor-signal conditioning, low-level current-to-voltage conversion, audio preamplification, active filtering, comparators with additional biasing, and general instrumentation. The 14-pin PDIP format also supports manual assembly and through-hole prototyping in laboratories, educational equipment, industrial control systems, and repair products.
When designing an LM324KN circuit, verify input and output voltage limits against the selected operating rail, including output swing limitations when driving capacitive loads. Place input compensation or bias resistors close to the relevant amplifier pins, keep feedback loops short, and provide stable bypassing at the supply pins to limit noise and prevent oscillation.
This product page combines the LM324KN package and feature information with practical analog-design guidance, application context, verified alternatives, and a parameter comparison for faster component selection.
Drop-in alternatives for LM324KN — 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 LM324KN (same form factor and footprint) — differing in Package, Number of Channels, Product Type, Mounting Type, Amplifier Type.
LM324N
✅ Drop-In ⚠️ Specs UnverifiedContact for price
View Datasheet →LM324ADR2G
✅ Drop-In ⚠️ Specs UnverifiedContact for price
View Datasheet →LM324BAIDR
✅ Drop-InContact for price
View Datasheet →LMC660
✅ Drop-In📋 Reference alternative (not in catalog)
LM2904P3
✅ Drop-In ⚠️ Specs UnverifiedContact for price
View Datasheet →LM324KN Maximum Ratings & Electrical Characteristics
| Amplifier Count | 4 circuits |
| Product Type | General-purpose operational amplifier |
| Number of Channels | 4 independent channels |
| Package | 14-PDIP |
| Pin Count | 14 pins |
| Mounting Type | Through-hole |
| Supply Configuration | Single supply or split supply |
| Maximum Supply Voltage | 36 V |
| Typical Supply-Current Drain | 0.8 mA |
| Common-Mode Input Range | Includes ground |
| ESD Protection | 2 kV |
| Frequency Compensation | Internal |
| RoHS Status | unknown |
| REACH Status | unknown |
| AEC-Q100 Qualification | not_applicable |
LM324KN Pin Configuration
| Pin 1 | OUT1 — Output of amplifier 1 |
| Pin 2 | IN1- — Inverting input of amplifier 1 |
| Pin 3 | IN1+ — Non-inverting input of amplifier 1 |
| Pin 4 | V- — Negative supply connection |
| Pin 5 | IN2+ — Non-inverting input of amplifier 2 |
| Pin 6 | IN2- — Inverting input of amplifier 2 |
| Pin 7 | OUT2 — Output of amplifier 2 |
| Pin 8 | OUT3 — Output of amplifier 3 |
| Pin 9 | IN3- — Inverting input of amplifier 3 |
| Pin 10 | IN3+ — Non-inverting input of amplifier 3 |
| Pin 11 | V+ — Positive supply connection |
| Pin 12 | IN4+ — Non-inverting input of amplifier 4 |
| Pin 13 | IN4- — Inverting input of amplifier 4 |
| Pin 14 | OUT4 — Output of amplifier 4 |
Typical Applications
LM324KN is suitable for 6 applications: Industrial Sensor Signal Conditioning, Current-to-Voltage Conversion, Audio Preamplification, Active Filtering and Control Loops, Battery-Powered Portable Instruments, Educational and Laboratory Analog Circuits.
Industrial Sensor Signal Conditioning
LM324KN fits industrial sensor-conditioning circuits that amplify low-level sensor outputs into a voltage range suitable for measurement or control. Its four independent channels can process separate inputs without requiring multiple packages, while internal frequency compensation simplifies closed-loop amplifier design. The common-mode input range includes ground, which is valuable when sensing signals near 0 V from resistive dividers, potentiometers, or resistive bridges. The 14-PDIP format also supports through-hole control boards that use conventional leaded assembly. Designers should verify output swing at the selected supply voltage and keep input and feedback routing short to preserve accuracy.
Recommended
Current-to-Voltage Conversion
LM324KN is useful in current-to-voltage converter circuits where a small shunt voltage must be amplified for an ADC, meter, or analog display. Because its common-mode input range includes ground, a shunt positioned near the ground return can be measured effectively with a single positive supply. The device provides four independently usable amplifiers, allowing one channel to perform conversion while the others support buffering, gain stages, or offset conditioning. Verify the maximum input and output voltages, account for input bias current when choosing shunt and feedback resistors, and confirm stability with the capacitance presented by the downstream ADC or display.
Recommended
Audio Preamplification
LM324KN can serve in general-purpose audio preamplifier and mixer stages built around small-signal source devices. Its four-channel organization permits multiple buffered inputs without using separate packages, and the low 0.8 mA typical supply-current drain suits low-power analog sections. The internal frequency compensation supports straightforward closed-loop voltage-amplifier configurations, including non-inverting and inverting stages. Audio-system design should still consider the source impedance, gain error caused by bias current, output-loading tolerance, and bandwidth requirements. A common-mode input range including ground supports single-supply biasing, provided the signal and output remain inside the device's specified swing limits.
Recommended
Active Filtering and Control Loops
LM324KN is appropriate for active filter, gain-control, and simple analog-control loops where four interchangeable amplifier channels improve board utilization. Its internally compensated design is intended for conventional closed-loop operation, so first-order and basic second-order filter sections can often be implemented directly with passive R and C networks. Component tolerances and the amplifier's finite gain and bandwidth still influence cutoff accuracy and phase margin. Keep the feedback components close to their associated pins, avoid long high-impedance routes, and evaluate the final response across the intended supply range. The DIP package through-hole footprint makes it convenient for educational, prototype, and legacy industrial-control boards.
Recommended
Battery-Powered Portable Instruments
LM324KN can fit portable measurement instruments and battery-operated control products that require multiple low-power analog channels. Its four independent amplifiers reduce package count, and the 0.8 mA typical supply-current drain helps conserve power relative to a design using four separate amplifiers. The common-mode range including ground is useful in systems that operate from one positive rail, while broad supply compatibility supports different battery-derived voltage options. Designers should check quiescent and load-current behavior at the intended temperature, confirm that output swing leaves adequate headroom for the ADC or comparator, and account for input bias current when source impedances become high.
Recommended
Educational and Laboratory Analog Circuits
LM324KN is well suited to educational laboratories, breadboard-based prototypes, and through-hole analog training systems. Four independent amplifiers on one 14-PDIP package let students build amplifier, comparator, summing, buffer, and active-filter circuits without separate packages for every stage. Internal frequency compensation simplifies introductory closed-loop experiments, while the ability to operate from single or split supplies demonstrates both common analog biasing methods. Before connecting student circuits, use current limiting and protected laboratory supplies. For precision exercises, include input bias current, output swing, and finite open-loop gain in the analysis rather than treating the amplifier as ideal.
Recommended
Recommended Products Summary
Engineering reference data for LM324KN — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LM324N | LM324A | LM324B | LMC660 | LM2904P3 |
|---|---|---|---|---|---|---|
| Package | 14-PDIP | 14-PDIP - same | 14-PDIP - same | 14-PDIP - same | 14-PDIP - same | 14-PDIP - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Amplifier Count | 4 circuits | 4 circuits | 4 circuits | 4 circuits | 4 circuits | 4 circuits |
| Special Characteristic | Standard LM324 general-purpose amplifier | Standard LM324 family | LM324A accuracy variant | Improved B-version specifications | Greater bandwidth and input resistance | LM2904 operating-grade profile |
Key Differentiators
- Four independent channels in one through-hole package (vs LM2904P3)
- Established LM324 electrical behavior (vs LMC660)
- Improved offset specification available in the related B version (vs LM324B)
Design Notes
Do not assume an ideal amplifier: the LM324 input bias current creates offset error across high source impedances, and its output cannot necessarily reach either supply rail. Select the feedback resistors with source impedance and bias current in mind, and confirm output swing for the actual load. When the LM324 is used as a comparator, use an appropriate pull-up or pull-down and include hysteresis where required by the input offset voltage.
Keep each amplifier's feedback loop physically compact and connect compensation or bias components directly to the relevant pins. Avoid routing high-impedance input nodes near power-supply traces and switching nodes. Place supply bypassing close to pins 4 and 11, with a short ground return, and preserve adequate copper around power connections for current flow and heat dissipation. Check the final PCB for unintended coupling between adjacent amplifier channels.
Estimated: with a 12 V input, a 5 V output, and a 10 mA load, linear-regulator dissipation is approximately 70 mW using P = (VIN - VOUT) × IOUT. Verify the actual source and output currents across all operating modes, including startup and load transients. The package and board copper must dissipate the resulting heat without pushing the junction beyond its device-specific temperature limit.
Operational-amplifier output stability can be affected by excessive capacitive loading, particularly when driving long cables, ADC inputs, or relay contacts. Add a small isolation resistor close to the output when capacitive loading is unavoidable, and evaluate the resulting gain response. Also avoid very high closed-loop gains with large feedback resistors unless the resulting bias-current error and bandwidth behavior have been checked.
Compliance Information
The LM324KN is a general-purpose analog IC and is not an AEC-Q100-qualified automotive ordering option. Current manufacturer material-declaration records are required to establish RoHS, REACH, lead-free, halogen-free, and conflict-minerals status.
