LM224DT - 4-Channel 1.3MHz Op Amp | STMicroelectronics
MPN: LM224DT ✓ ActiveLM224DT Overview
An operational amplifier is a high-gain differential amplifier whose feedback network determines its closed-loop behavior. The LM224 family belongs to the linear-amplifier hierarchy: operational amplifier, voltage-feedback amplifier, analog signal-conditioning IC, and semiconductor. Its four amplifiers can operate independently, allowing one package to implement multiple filtering, amplification, comparison, or buffering functions while also supporting split-supply operation.
Key features include four independent channels, internal frequency compensation, a 1.3 MHz gain bandwidth product, low input bias current, and low power-supply current. The wide 3 V to 30 V operating range permits use with 5 V, 12 V, 15 V, and 24 V supply systems. The device is available in the 14-pin SOIC outline identified by the T packaging suffix.
Each channel uses an internally compensated architecture that simplifies closed-loop design without an external frequency-compensation network. Input offset voltage is specified up to 7 mV, while the gain bandwidth product determines how quickly a closed-loop circuit can amplify signals. The amplifiers are intended for general-purpose precision rather than high-speed or high-current applications, making them suitable for slow sensor signals and buffered control systems.
Typical uses include industrial sensor interfaces, low-frequency active filters, transducer amplifiers, audio and communication buffers, battery-powered instrumentation, and four-channel process monitoring. A single package can reduce board area when four independent analog channels are required, although thermal management and input common-mode limits remain important when operating from higher supply voltages.
Designers should verify input and output common-mode ranges, output swing, supply current, and stability for the intended load using the manufacturer datasheet. Input and output decoupling should be placed close to the supply pins, and unused amplifier inputs should be biased to a defined common-mode voltage to prevent unstable operation.
This page combines verified distributor and manufacturer information, pin-level guidance, practical application notes, and drop-in replacement analysis. It also distinguishes electrically compatible replacements from merely similar amplifiers, helping engineers choose a replacement by package, pinout, supply range, bandwidth, and system requirements.
Drop-in alternatives for LM224DT — 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 LM224DT (same form factor and footprint) — differing in Package, RoHS Status, Amplifier Type, Product Type.
LM124D
✅ Drop-In📋 Reference alternative (not in catalog)
LM224D
✅ Drop-InContact for price
View Datasheet →TS27L2CDT
✅ Drop-In📋 Reference alternative (not in catalog)
LM2902D
✅ Drop-InContact for price
View Datasheet →LM224A
✅ Drop-In📋 Reference alternative (not in catalog)
LM224DT Maximum Ratings & Electrical Characteristics
| Number of Amplifiers | 4 circuits |
| Amplifier Type | General-purpose operational amplifier |
| Gain Bandwidth Product | 1.3 MHz |
| Supply Voltage Range | 3 V to 30 V |
| Input Offset Voltage | 7 mV maximum |
| Frequency Compensation | Internal |
| Package | 14-pin SOIC |
| Mounting Type | Surface mount |
| RoHS Status | Compliant |
| Automotive Qualification | Not applicable |
LM224DT 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 or ground |
| 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- — Negative supply or ground |
| 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
LM224DT is suitable for 6 applications: Industrial Sensor Signal Conditioning, Quad Active Filter Stages, Process-Control Buffering, Audio and Communication Buffering, Battery-Powered Instrumentation, Comparator and Threshold Detection.
Industrial Sensor Signal Conditioning
The LM224DT is well suited to amplifying and conditioning low-frequency outputs from temperature, pressure, and position sensors because each package contains four independent, internally compensated amplifiers. With a 3 V to 30 V supply range, the device can operate from 5 V, 12 V, or 24 V industrial rails, while its 1.3 MHz gain bandwidth product covers many sensor-bandwidth requirements. A practical implementation would use one channel as a differential input stage and another as a buffer or active-filter stage. Engineers must still verify the input common-mode range and output swing at the selected supply voltage, because sensor excitation and transducer offsets can move the signal outside those limits.
Recommended
Quad Active Filter Stages
Four independent LM224DT channels can implement four sections of a low-frequency active filter without using four separate amplifier packages. Internal frequency compensation removes the need for external compensation in ordinary closed-loop configurations, while the 1.3 MHz gain bandwidth product supports filter bandwidths well below the amplifier unity-gain frequency. The 14-pin SOIC package also simplifies routing and reduces package count on analog control boards. Filter design must account for the amplifier's gain-bandwidth limit, output-current capability, and stability when driving the selected capacitor and resistor network, particularly when cascading multiple sections with high Q factors.
Recommended
Process-Control Buffering
The LM224DT can buffer sensor and controller signals in industrial process-control systems that operate from 12 V or 24 V rails. Its four independent channels provide flexible gain, impedance conversion, and signal isolation within a single 14-pin SOIC, and the internal compensation allows straightforward voltage-feedback configurations. This arrangement can reduce loading of a transducer or divider network before a downstream converter or controller samples the signal. The designer should confirm that output swing provides the required logic or sensor-interface levels and that each input is biased within the common-mode range. Input protection may also be needed when field wiring exposes the amplifier to transients beyond its specified limits.
Recommended
Audio and Communication Buffering
The LM224DT can buffer low-level audio or communication signals when the design requires multiple general-purpose amplifier channels and a supply above the usual 5 V limit. Its internally compensated, high-gain amplifier architecture supports voltage-feedback buffering, gain adjustment, and crossover networks, while the 1.3 MHz bandwidth is appropriate for voice-band and many control-signal paths. The wide 3 V to 30 V supply range also permits dual-rail operation where supported by the signal and output limits. Audio designers should evaluate distortion, slew rate, output swing, and channel-to-channel behavior from the datasheet rather than assuming the part matches a dedicated low-noise audio amplifier.
Recommended
Battery-Powered Instrumentation
For portable measurement equipment, the LM224DT can implement four low-frequency analog functions from a single supply within its 3 V to 30 V operating range. Its low-power-consumption design and four-channel integration reduce board area compared with four separate single or dual amplifier packages. Typical uses include sensor conditioning, gain stages, and output buffering for a portable meter. The trade-off is that 14-pin SOIC construction is less compact than modern chip-scale packages, and the exact supply-current contribution depends on operating voltage, load, and channel utilization. Battery life calculations should use the manufacturer electrical-characteristics table for the actual quiescent and load currents.
Recommended
Comparator and Threshold Detection
Although primarily an operational amplifier, the LM224DT can operate as an open-loop comparator for slow threshold detection and relay-control signals. Four independent channels allow monitoring of multiple limits, and the 3 V to 30 V supply range accommodates both low-voltage and industrial control systems. Compared with a dedicated high-speed comparator, the LM224DT trades speed for a very wide supply capability and general-purpose flexibility. When used as a comparator, verify output saturation levels and input overdrive behavior in the datasheet. Add output pull-up or pull-down components if the open-collector output configuration requires them, and avoid using the amplifier as a comparator where propagation delay would affect the control response.
Recommended
Recommended Products Summary
Engineering reference data for LM224DT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LM124D | LM224D | TS27L2CDT | LM2902D | LM224A |
|---|---|---|---|---|---|---|
| Package | SOIC-14 | SOIC-14 | SOIC-14 | SOIC-14 | SOIC-14 | SOIC-14 |
| Brand | STMicroelectronics | Texas Instruments | Philips Semiconductors | STMicroelectronics | Texas Instruments | Texas Instruments |
| Number of Amplifiers | 4 | 4 | 4 | 4 | 4 | 4 |
| Single-Supply Operation | Yes | Yes | Yes | Yes | Yes | Yes |
| Split-Supply Operation | Yes | Yes | Yes | Yes | Yes | Yes |
Key Differentiators
- Direct same-brand family alternative with matching offset rating (vs TS27L2CDT)
- Documented pin-to-pin replacement with lower maximum offset (vs LM124D)
- Higher verified bandwidth than the LM2902D candidate (vs LM2902D)
Design Notes
The LM224DT supports a 3 V to 30 V supply, but the usable signal range changes with that supply. Do not assume that a 24 V input can be amplified directly into a 24 V output. First confirm the input common-mode range and output swing in the manufacturer electrical-characteristics table, then size the feedback network so the output remains within the linear region. The ground pins are pins 4 and 11; use a low-impedance ground plane and route both ground connections without long traces.
A drop-in package match does not guarantee identical behavior across every operating condition. The documented LM124D has a 5 mV maximum offset versus 7 mV for LM224DT, and LM2902D has a 1 MHz bandwidth versus 1.3 MHz for LM224DT. Before substituting either device, compare input bias current, common-mode range, output swing, slew rate, supply current, temperature grade, and output-sink capability. These differences can alter sensor accuracy or loop stability even when the PCB remains unchanged.
Place the bypass capacitor adjacent to the positive supply connection and return it directly to the ground reference. Because this is a four-amplifier package, keep sensitive input traces away from outputs 3 and 4, especially where a high-gain channel can drive adjacent circuitry. Use a continuous ground plane, provide adequate decoupling at the supply entry point, and check the final board for EMI coupling between the high-impedance input nodes and output routing.
The internal compensation of the LM224DT is intended to simplify conventional voltage-feedback use, but closed-loop stability still depends on gain, load, and feedback topology. For high-noise-gain configurations, use the manufacturer's stability guidance and verify the design with the intended output load. If driving substantial capacitive cable capacitance, add an isolation resistor and evaluate the resulting step response; nominal bandwidth alone does not guarantee robust settling.
Compliance Information
The verified distributor data identifies LM224DT as RoHS3 compliant. The supplied records do not establish REACH, lead-free, halogen-free, conflict-minerals, or automotive qualification status.