LM324DG - 4-Channel 1 MHz Op Amp, 3-32 V | onsemi
MPN: LM324DG ✓ ActiveLM324DG Overview
An operational amplifier, or op amp, is a voltage-controlled differential amplifier whose open-loop gain is used to amplify a difference between two input signals. The LM324 belongs to the broader amplifier IC hierarchy: operational amplifier, analog amplifier, semiconductor, and integrated circuit. Its true differential inputs and ability to operate from a single positive supply are particularly useful in circuits that do not have a negative reference rail.
Key features include four amplifier channels in one package, a 1 MHz gain-bandwidth product, a 0.6 V/us slew rate, input offset voltage ratings of 5 mV to 7 mV depending on the cited source, and a minimum common-mode rejection ratio of 65 dB. The 3 V to 32 V operating supply range supports both low-voltage logic systems and conventional industrial analog circuits without requiring a separate negative supply.
The LM324 architecture is intended for general-purpose voltage amplification rather than precision or high-speed signal conditioning. Its relatively wide input offset voltage and modest gain-bandwidth product make it most appropriate for audio, transducer, buffering, and feedback-control stages where moderate accuracy and bandwidth are sufficient. Designers should account for input offset when measuring small signals and verify gain-bandwidth requirements for closed-loop applications.
Typical uses include microphone preamplification, active audio-channel amplification, low-frequency sensor interfaces, industrial control loops, and general buffer stages. Because each channel can be assigned to a different signal or function, four independent amplifier circuits can be implemented on one board while reducing component count and simplifying routing.
The primary design consideration is the absence of a negative supply in many applications. Input and output signals must remain within the device's common-mode input and output swing limits, so a negative rail is not required but can improve signal-headroom flexibility. Input and output decoupling should follow the manufacturer datasheet's recommended application circuit, and unused amplifier inputs must be biased so they remain in a defined operating state.
This product page consolidates the verified LM324DG specifications, distributor references, drop-in replacement candidates, package details, and practical design guidance. It also distinguishes direct same-package substitutes from functional alternatives so engineers can narrow a replacement search without assuming that every quad op amp is electrically or mechanically interchangeable.
Drop-in alternatives for LM324DG — 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 LM324DG (same form factor and footprint) — differing in Amplifier Type, Input Offset Voltage, Package, Supply Voltage Range, Input Type.
LM324ADR2G
✅ Drop-InContact for price
View Datasheet →LM324ADG
✅ Drop-In📋 Reference alternative (not in catalog)
LM324SNG
✅ Drop-In📋 Reference alternative (not in catalog)
LM324DR
✅ Drop-InContact for price
View Datasheet →LM324ADR2G
✅ Drop-InContact for price
View Datasheet →LM324DG Maximum Ratings & Electrical Characteristics
| Number of Channels | 4 channels |
| Amplifier Type | Single-supply quad operational amplifier with true differential inputs |
| Supply Voltage Range | 3 V to 32 V |
| Gain-Bandwidth Product | 1 MHz |
| Slew Rate | 0.6 V/us |
| Input Offset Voltage | 5 mV to 7 mV |
| Minimum Common-Mode Rejection Ratio | 65 dB |
| Number of Pins | 14 pins |
| Package | 14-pin SOIC |
| Mounting Type | Surface mount |
| Operating Temperature Grade | Commercial temperature grade |
| Input Type | True differential inputs |
| Power Supply Configuration | Single supply |
LM324DG Pin Configuration
| Pin 1 | OUT1 — Amplifier 1 output |
| Pin 2 | -IN1 — Inverting input of amplifier 1 |
| Pin 3 | +IN1 — Non-inverting input of amplifier 1 |
| Pin 4 | V- — Negative supply or ground connection |
| Pin 5 | +IN2 — Non-inverting input of amplifier 2 |
| Pin 6 | -IN2 — Inverting input of amplifier 2 |
| Pin 7 | OUT2 — Amplifier 2 output |
| Pin 8 | OUT3 — Amplifier 3 output |
| 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 — Amplifier 4 output |
Typical Applications
LM324DG is suitable for 6 applications: Audio Signal Conditioning, Industrial Sensor Interfaces, Low-Frequency Control Loops, Transducer Amplification, Communications Interface Buffers, Portable and Battery-Powered Equipment.
Audio Signal Conditioning
The LM324DG fits low-frequency audio conditioning because it combines four general-purpose amplifier channels with a 1 MHz gain-bandwidth product and 0.6 V/us slew rate in one 14-pin SOIC package. It can implement preamplifier, mixer, and buffer stages around microphones or line-level sources without requiring four separate packages. The 3 V to 32 V supply range supports portable equipment operating from 5 V as well as higher-voltage analog systems. The main limitation is input offset voltage of up to 7 mV, which should be considered when signals approach the noise floor, plus the need to keep outputs within the finite output-swing range. The device is better for conventional audio bands than demanding high-fidelity paths requiring lower offset and distortion.
Recommended
Industrial Sensor Interfaces
The LM324DG is appropriate for buffering and scaling outputs from industrial sensors when the required bandwidth is modest. Four independent channels allow two differential amplifiers and two additional signal-conditioning stages to share one 14-pin SOIC package, reducing board area and component count. Its 3 V to 32 V supply range is useful for 24 V industrial systems, while true differential inputs support signals referenced around a single supply. However, the cited input offset voltage of 5 mV to 7 mV can create meaningful error for low-level sensors, and the 1 MHz gain-bandwidth product limits high-speed closed-loop operation. Designers should also verify the common-mode range for the actual sensor output and avoid saturating the amplifier near supply-limit conditions.
Recommended
Low-Frequency Control Loops
The LM324DG can serve as the active element in low-frequency proportional, integral, or general feedback-control circuits. Its four-channel arrangement supports a controller plus signal buffers without requiring multiple amplifier packages, while the 0.6 V/us slew rate and 1 MHz gain-bandwidth product are generally adequate for slow plant dynamics. The single-supply operation simplifies circuits that previously required positive and negative rails. The design trade-off is that the LM324 is not a precision amplifier: input offset voltage can shift the control operating point, and output swing limitations may require biasing around mid-supply. Stable loop design therefore requires checking noise gain, phase margin, output loading, and compensation against the manufacturer application guidance.
Recommended
Transducer Amplification
The LM324DG is suitable for basic voltage amplification from resistive transducers such as temperature, position, and light sensors when only moderate accuracy is required. Its true differential input architecture can reject common disturbances when the two inputs are driven with opposite signals, and all four channels remain available for instrumentation or channel multiplexing. The 3 V minimum supply supports compact sensor systems, while the 32 V maximum expands industrial headroom. The primary engineering concern is offset error: at the cited 7 mV maximum, a low-level transducer signal can experience meaningful percentage error. Designers should calculate the full signal-chain error, include suitable input filtering, and ensure sensor outputs remain inside the common-mode input range.
Recommended
Communications Interface Buffers
The LM324DG can provide general-purpose buffering and gain stages around low-speed communications interfaces, particularly in industrial equipment where signal integrity requirements are modest. Four channels in a single 14-pin SOIC allow receive and transmit paths to be supported economically, while the 1 MHz gain-bandwidth product covers many baseband control signals. The amplifier's broad 3 V to 32 V supply range accommodates multiple system rails, and true differential inputs suit balanced arrangements. It should not be treated as a high-speed line driver or modern rail-to-rail communications buffer: slew rate, output swing, input capacitance, and channel-to-channel behavior must be checked. For higher data rates or low-voltage interface nodes, a dedicated transceiver is the better architectural choice.
Recommended
Portable and Battery-Powered Equipment
The LM324DG is usable in portable or battery-powered equipment when the signal bandwidth is low and the amplifier operates from a 5 V rail. Four channels reduce the number of packages required for microphone, sensor, and control amplification, which helps conserve board area. The minimum 3 V operating voltage supports systems operating near a regulated 3.3 V rail, while true differential inputs are convenient for sensor signals. The tradeoff is that this general-purpose amplifier does not provide a verified rail-to-rail output specification in the supplied data, so a 3.3 V design must verify output swing across temperature and load. Input offset of up to 7 mV can also be significant for low-voltage battery sensors, making biasing and error budgeting essential.
Recommended
Recommended Products Summary
Engineering reference data for LM324DG — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LM324ADR | LM324ADG | LM324SNG | LM324DR | LM324AD |
|---|---|---|---|---|---|---|
| Package | 14-pin SOIC | 14-pin SOIC | 14-pin SOIC | 14-pin SOIC | 14-pin SOIC | 14-pin SOIC |
| Brand | onsemi | onsemi | onsemi | onsemi | Texas Instruments | Texas Instruments |
| Number of Channels | 4 | 4 | 4 | 4 | 4 | 4 |
Key Differentiators
- Four general-purpose amplifiers in one package (vs LM324DR)
- Direct onsemi sourcing option (vs LM324AD)
- Single-supply compatibility (vs LM324ADR)
- Verified bandwidth and slew-rate positioning (vs LM324SNG)
Design Notes
Do not assume that a 3 V to 32 V supply rating makes the output rail-to-rail. According to the onsemi LM324 datasheet, the output swing and common-mode input range have finite limits, particularly near the positive supply. Bias signals around the available output range and verify worst-case load, temperature, and supply conditions. Also check whether the single-supply input range includes ground throughout the complete operating range; this determines whether an external bias network is required for bipolar sensor signals.
Place the LM324DG close to the signals it processes and route each input away from switching nodes and high-current traces. Maintain a quiet ground reference for pin 4 and use the decoupling arrangement specified in the manufacturer datasheet. Because all four channels share one package, internal die heating can affect every channel; keep high-current or dissipative circuitry away from the SOIC and avoid placing thermal hotspots underneath the package.
Do not leave an unused amplifier input floating. An unused non-inverting input should be tied to a defined bias point, commonly the same reference used by its inverting input, while the output remains unconnected. Before substituting another manufacturer's LM324 variant, verify that pin numbering, exposed thermal-pad usage, input and output assignments, supply pins, and package dimensions match the LM324DG 14-pin SOIC footprint.
The 1 MHz gain-bandwidth product and 0.6 V/us slew rate are the primary limits for small-signal and large-signal behavior. Check the required closed-loop gain, noise gain, output load, and target frequency before committing to the LM324DG. For high-Q filters or very low-frequency instrumentation, excessive noise gain can reduce usable bandwidth. Add input filtering only after checking that added capacitance does not upset feedback-loop stability.
Compliance Information
The supplied search results do not provide definitive extracted compliance declarations for the LM324DG. The commercial-temperature designation does not establish AEC-Q100 status. Current onsemi product and compliance documentation should be checked before production release.