MC33079D - 15 MHz Low-Noise Quad Op Amp | onsemi
MPN: MC33079D ✓ ActiveMC33079D Overview
An operational amplifier, or op amp, is a high-gain differential amplifier whose external feedback defines its gain and bandwidth. Within the semiconductor hierarchy, an op amp belongs to the linear amplifier and analog signal-conditioning categories. It is used to amplify weak sensor signals, buffer high-impedance sources, implement active filters, and provide gain in audio and control paths. The MC33079 integrates four amplifiers in one package, reducing board area while providing consistent device-level matching.
The MC33079D combines 4.5 nV/√Hz low-voltage-noise performance with a 15 MHz gain-bandwidth product. Its 7 V/µs slew rate supports faster large-signal transitions than slower general-purpose amplifiers. Additional features include 0.002% distortion, a large output-voltage swing, 2 kV ESD protection, and a macromodel for simulation. These characteristics make the device relevant to microphone preamplification, active audio crossover networks, audio buffer stages, and precision low-frequency signal conditioning.
The bipolar architecture uses high-frequency PNP input transistors to provide low input-voltage noise. Because the amplifiers are not rail-to-rail, system designers should verify input common-mode range and output swing against the selected supply voltage. The listed operating-voltage range of 2.5 V to 15 V permits operation from low-voltage analog systems through conventional ±15 V bipolar supplies. The four amplifiers share a common package, although each output still requires suitable output-current and stability analysis for its load.
Typical uses include four-channel audio buffering, low-level microphone amplification, active equalization, filtering, instrumentation interfaces, and general-purpose analog signal processing. In multi-amplifier designs, adjacent channels can implement gain, filtering, and drive functions without requiring four separate packages. The device can also serve in laboratory and industrial control circuits where low noise and a 15 MHz bandwidth are more important than rail-to-rail input or output operation.
The primary design consideration is power-supply configuration. Decouple each supply connection with a local ceramic bypass capacitor, maintain a short return path, and place input and feedback components close to the relevant amplifier pins. Avoid using the quad amplifier merely because four circuits are required: confirm common-mode limits, output-swing headroom, capacitive-load stability, noise-gain bandwidth, and channel-to-channel layout symmetry before releasing the PCB.
This product record combines the MC33079D manufacturer-datasheet specifications, package information, search queries, and cross-reference findings with practical design guidance. It also highlights genuine replacement constraints: a mechanically similar 14-pin SOIC amplifier is not automatically a drop-in replacement, so common-mode range, bias current, stability, noise, and exact pin assignment must be checked before substitution.
Drop-in alternatives for MC33079D — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
OPA1654
✅ Drop-In📋 Reference alternative (not in catalog)
MC33079D Maximum Ratings & Electrical Characteristics
| Amplifier Type | Quad low-noise operational amplifier |
| Number of Amplifiers | 4 circuits |
| Input Transistor Technology | Bipolar |
| Voltage-Noise Density | 4.5 nV/√Hz |
| Gain-Bandwidth Product | 15 MHz |
| Slew Rate | 7 V/µs |
| Total Distortion | 0.002% |
| ESD Protection | 2 kV |
| Minimum Supply Voltage | 2.5 V |
| Maximum Supply Voltage | 15 V |
| Typical Total Supply Voltage | ±18 V |
| Package | 14-pin SOIC |
| Mounting Type | Surface mount |
| Macromodel Availability | Included |
| Frequency Stability | Excellent |
MC33079D 14-pin soic Pin Configuration Guide
Pin configuration for MC33079D (14-pin soic package). This analog component features input, output, and power supply pins. Refer to the manufacturer datasheet for offset null, compensation, and enable pin configurations. Ideal for signal conditioning and amplifier circuits.
No detailed pinout data available for MC33079D.
Refer to the datasheet for full pin configuration.
Typical Applications
MC33079D is suitable for 6 applications: Low-Level Audio Preamplification, Active Audio Crossover, Four-Channel Audio Buffering, Precision Active Filtering, Industrial Sensor Signal Conditioning, General Analog Instrumentation.
Low-Level Audio Preamplification
The MC33079D fits low-level audio preamplification because its 4.5 nV/√Hz voltage-noise density preserves small signals without adding unnecessary broadband noise. A 15 MHz gain-bandwidth product supports closed-loop gains commonly used around microphone and line-level stages, while the 7 V/µs slew rate provides additional margin during transient-heavy signals. Each channel can implement a noninverting or inverting gain stage with conventional feedback. The design should still verify input bias current, output swing, and stable noise gain against the selected operating voltage.
Recommended
Active Audio Crossover
The MC33079D is suitable for active crossover and equalization networks because its 15 MHz gain-bandwidth product comfortably covers audio-band closed-loop filtering, while 4.5 nV/√Hz noise supports low-level high-pass, low-pass, and peaking stages. The 7 V/µs slew rate improves large-signal behavior compared with slower precision amplifiers. Four amplifiers in one 14-pin SOIC can implement several filter sections, but each feedback network must preserve the required noise gain. Check component tolerances and simulate the complete filter for stability.
Recommended
Four-Channel Audio Buffering
A four-channel buffering application benefits from integrating the MC33079D's four amplifiers in one 14-pin SOIC. Its 15 MHz gain-bandwidth product handles buffer gains near unity with more bandwidth than required for most audio signals, and the 4.5 nV/√Hz input-noise density avoids degrading a low-level source. The 7 V/µs slew rate supports dynamic signal transitions. Verify output-current demand, load capacitance, and the datasheet's recommended output-decoupling arrangement for every channel.
Recommended
Precision Active Filtering
The MC33079D can implement precision active filters when the required closed-loop bandwidth remains comfortably below its 15 MHz gain-bandwidth product and the filter's noise gain does not create an unintended stability limitation. Its 4.5 nV/√Hz voltage-noise density is useful for filtering low-level instrumentation signals, while the 7 V/µs slew rate provides useful transient margin. Confirm resistor accuracy, input bias current effects, output swing, and common-mode range in the target filter topology before layout release.
Recommended
Industrial Sensor Signal Conditioning
The MC33079D is appropriate for conditioning moderate-bandwidth industrial sensor signals when low noise is valuable and bipolar-input behavior is acceptable. Its 4.5 nV/√Hz noise density benefits strain, pressure, and audio-derived sensors, while the 15 MHz gain-bandwidth product allows useful closed-loop gain. The 7 V/µs slew rate helps preserve square-wave and transient content. Industrial designs should account for input-bias-current error, supply rejection within the actual operating frequency range, common-mode limits, and isolation from switching circuitry.
Recommended
General Analog Instrumentation
The MC33079D supports general-purpose instrumentation because four independent amplifiers provide flexible gain, buffering, and summing functions in one package. Its 4.5 nV/√Hz noise density is beneficial when amplifying small sensor outputs, and the 15 MHz gain-bandwidth product provides enough bandwidth for many measurement-band circuits. The 7 V/µs slew rate limits large-signal distortion in test and control paths. Confirm whether the input and output common-mode ranges satisfy the actual measurement node and power-supply configuration.
Recommended
Recommended Products Summary
Engineering reference data for MC33079D — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | OPA1654 |
|---|---|---|
| Brand | onsemi | Texas Instruments |
| Package | 14-pin SOIC | 14-pin surface mount |
| Amplifier Count | 4 | 4 |
| Input Architecture | Bipolar | JFET |
Key Differentiators
- Low-noise bipolar input stage (vs OPA1654)
- 15 MHz gain-bandwidth product (vs OPA1654)
- Four matched functions in one 14-pin SOIC (vs OPA1654)
Design Notes
Place the supply bypass capacitor immediately beside the MC33079D power and ground pins, with the shortest practical return path. Connect each amplifier's feedback resistors and input components close to their associated pins to minimize parasitic capacitance and feedback-loop delay. The quad layout is convenient for channel symmetry, but a common ground plane and clean separation from switching regulators remain important for preserving the device's 4.5 nV/√Hz noise performance.
Do not assume that any 14-pin quad amplifier is interchangeable with the MC33079D. Check the exact SOIC pin assignment, input common-mode range, output swing, input bias current, noise gain, and capacitive-load behavior. The MC33079D is not described as rail-to-rail, so verify both inputs and outputs remain inside their valid ranges at minimum and maximum supply voltages. Changing the amplifier architecture from bipolar to JFET can alter bias-current error and circuit behavior materially.
Analyze each closed-loop stage for stability using the actual feedback topology, source impedance, load capacitance, and PCB parasitics. The 15 MHz gain-bandwidth product and 7 V/µs slew rate provide useful dynamic performance, but they do not guarantee stability at every noise gain or capacitive load. For high-Q active filters, include component tolerances and amplifier finite-gain behavior in simulation, and keep sensitive input nodes physically separated from clock, switching, and high-current return paths.
Compliance Information
Compliance declarations are not stated in the available component records and must be confirmed from the manufacturer documentation or current declarations before release to a regulated market.