STMicroelectronics MC33079D

Overview

MC33079D from STMicroelectronics is a low-noise quad operational amplifier in SO-14 package, designed for high-fidelity audio signal conditioning. It delivers 4.5 nV/√Hz input voltage noise, 15 MHz gain bandwidth product, and 7 V/µs slew rate, with ±14.3 V output swing at ±15 V supply-enabling clean amplification in preamp and active filter stages of professional audio equipment.

For engineers reviewing the MC33079D datasheet, MC33079D pinout, MC33079D application, or MC33079D equivalent, key selection criteria include input offset drift (2 µV/°C), THD of 0.002% at 20 Hz–20 kHz, channel separation of 120 dB, and guaranteed operation from –40 °C to +125 °C in industrial audio systems.

Technical Context

The MC33079D integrates four independent high-slew-rate op-amps on a single monolithic die, each featuring internally compensated unity-gain-stable architecture with 9 MHz open-loop bandwidth. Its bipolar input stage ensures low input bias current (250–800 nA) and symmetrical source/sink output drive capability (15–37 mA).

Designed for wide-supply operation (±2.5 V to ±15 V), it maintains stable phase margin (30° at 100 pF load) and gain margin (–6 dB) under capacitive loading-critical for active crossover networks and multi-stage feedback topologies where stability margins directly impact transient fidelity.

Key Specifications

Pinout & Package

MC33079D uses the SO-14 (small outline, 14-pin) plastic micropackage with 1.27 mm pitch, JEDEC MS-012AC compliant, and ECOPACK® RoHS-compliant construction.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quad op-amp applications.

Compared with NE5534AD and LM324DT, MC33079D uniquely balances low noise, high speed, quad integration, and industrial temperature range-making it optimal for space-constrained, high-linearity multi-channel analog signal chains where discrete solutions increase BOM count and matching complexity.

Availability

MC33079D is available at Aetrix Electronics and suitable for professional audio mixer design, industrial sensor signal conditioning, and automotive cabin audio preamplification requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MC33079D includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, power ICs, sensors, and analog components for industrial, automotive, and consumer markets.

The MC33079D belongs to ST's legacy precision analog amplifier product line, engineered specifically for high-fidelity audio and industrial measurement applications demanding low noise, wide bandwidth, and robust thermal performance.

FAQ

Is MC33079D pin-compatible with MC33078D?

No. MC33079D is a quad op-amp in SO-14; MC33078D is a dual op-amp in SO-8. Pin counts and internal channel mapping differ fundamentally-direct replacement requires PCB redesign. The MC33079D pinout supports four independent amplifiers with shared supplies, while MC33078D routes only two.

Can MC33079D operate from a single +12 V supply?

Yes, but with reduced output swing and input common-mode range. With VCC+ = +12 V and VCC– = 0 V, the output can swing to approximately +10.5 V / –0.5 V, and Vicm is limited to 0 V to +10 V. For true AC-coupled audio use, a virtual ground at +6 V is required via resistive divider and bypass capacitor.

What is the maximum capacitive load MC33079D can drive without oscillation?

Stable with ≤100 pF capacitive load when configured as unity-gain follower. At higher capacitance (e.g., >200 pF), phase margin degrades below 30°, risking ringing or oscillation. For loads >100 pF, add a 10–47 Ω series resistor between output and capacitor to isolate reactive feedback.

Does MC33079D support rail-to-rail input or output?

No. Input common-mode range extends to ±13 V to ±14 V with ±15 V supplies-within 1–2 V of rails-but does not reach them. Output swing is ±14.3 V/±14.6 V, leaving ~0.7 V saturation voltage. It is not a rail-to-rail op-amp; for true RRO, consider ST's TS912IDT or similar modern alternatives.