The STMicroelectronics MC4558CN is a dual general-purpose operational amplifier designed for a broad range of analog signal processing applications. It features low noise, wide bandwidth, and high output drive capability, making it suitable for audio preamplifiers, active filters, and signal conditioning circuits. The device is supplied in an 8-pin dual in-line package (DIP) and operates over a wide range of power supply voltages, providing flexibility for both single-supply and dual-supply configurations. Its internal architecture is designed to maintain high common-mode rejection and low total harmonic distortion, making it a reliable choice for precision analog designs.

## Electrical Characteristics

The MC4558CN operates over a supply voltage range from ±3V to ±18V, or 6V to 36V for single-supply operation. Its quiescent current per amplifier is typically 1.0 mA, allowing for low-power applications. The input offset voltage is typically 2 mV with a maximum of 7 mV at 25°C, and the input bias current is typically 50 nA, with a maximum of 250 nA, enabling high-impedance applications. The input resistance is 2 MΩ typically, while the differential input voltage rating extends to the full power supply range.

## Voltage Gain and Frequency Response

The open-loop voltage gain (A_VOL) is typically 100 dB at low frequencies, ensuring strong amplification for small signals. The gain-bandwidth product is 3 MHz, which supports applications requiring moderate frequency response, while the slew rate is 9 V/µs typical, allowing adequate performance in audio and low-frequency signal processing. The device exhibits a total harmonic distortion of 0.003% under standard operating conditions, ensuring minimal signal degradation in high-fidelity analog circuits.

## Input and Output Specifications

The MC4558CN features input voltage ranges from -Vcc + 2V to +Vcc - 2V, allowing for a wide dynamic range. The common-mode rejection ratio (CMRR) is typically 90 dB at 1 kHz, supporting accurate differential signal processing. The output voltage swing is ±13.5 V with ±15 V supplies into a 2 kΩ load, and the device can drive loads as low as 2 kΩ, with short-circuit protection limiting output current to 40 mA. Its output impedance is low, typically 75 Ω, enabling proper interfacing with subsequent stages without significant voltage drop.

## Noise Performance

Low noise is a key feature of the MC4558CN. The equivalent input noise voltage is 30 nV/√Hz at 1 kHz, making it suitable for audio applications and sensitive measurement circuits. The device also has a low input current noise of 0.5 pA/√Hz, ensuring minimal contribution to overall system noise in high-impedance configurations.

## Power Dissipation and Thermal Characteristics

The maximum power dissipation per package is 500 mW at 25°C ambient temperature, with thermal resistance from junction to ambient of 100°C/W. These ratings enable operation over a broad temperature range from -40°C to +85°C without derating, supporting robust performance in both industrial and consumer electronics.

## Packaging and Pin Configuration

The MC4558CN is supplied in an 8-lead dual in-line package (DIP-8). Pin 1 and pin 5 are the inverting inputs of the two amplifiers, while pin 2 and pin 6 are the non-inverting inputs. Pin 3 and pin 7 serve as the outputs, and pins 4 and 8 are for negative and positive supply connections, respectively. This pinout allows easy integration into standard PCB layouts and supports typical dual-op-amp applications like summing amplifiers, active filters, and instrumentation amplifiers.

## Typical Applications

The MC4558CN is widely used in audio preamplifiers due to its low noise and low distortion characteristics. It is suitable for active filters, including low-pass, high-pass, and band-pass designs, where precision and stability are required. Instrumentation circuits, including differential amplifiers and signal conditioning stages, benefit from its high CMRR and low input bias current. It can also be applied in voltage followers, integrators, and analog computation circuits, given its moderate bandwidth and high linearity.

## Reliability and Performance Considerations

The MC4558CN exhibits robust performance over temperature variations, with minimal drift in offset voltage and gain. Designers often utilize external compensation capacitors to optimize frequency response in high-gain configurations. The device is compatible with standard analog signal design practices and can interface with both TTL and CMOS logic levels if properly biased. Its dual-amplifier configuration reduces component count in multi-stage designs, enhancing layout efficiency and cost-effectiveness.

## Design Notes

For optimal performance, decoupling capacitors should be placed close to the power supply pins to minimize noise coupling. Proper layout techniques, including short input traces and ground plane utilization, improve noise immunity and maintain the integrity of high-impedance signals. The MC4558CN’s internal compensation ensures stability for unity-gain follower configurations, making it suitable for buffer stages in precision measurement and audio signal chains.

## Summary of Key Specifications

* Supply Voltage: ±3V to ±18V (dual), 6V to 36V (single)
* Quiescent Current: 1.0 mA per amplifier
* Input Offset Voltage: 2 mV typical, 7 mV max
* Input Bias Current: 50 nA typical, 250 nA max
* Input Resistance: 2 MΩ typical
* Voltage Gain: 100 dB typical
* Gain-Bandwidth Product: 3 MHz
* Slew Rate: 9 V/µs typical
* Total Harmonic Distortion: 0.003%
* Common-Mode Rejection Ratio: 90 dB typical
* Output Voltage Swing: ±13.5 V into 2 kΩ load
* Short-Circuit Output Current: 40 mA max
* Equivalent Input Noise: 30 nV/√Hz at 1 kHz
* Thermal Resistance (Junction to Ambient): 100°C/W
* Operating Temperature Range: -40°C to +85°C
* Package: 8-pin DIP

The MC4558CN remains a versatile, high-performance dual operational amplifier, suitable for precision audio, signal conditioning, and general-purpose analog applications requiring low noise, moderate bandwidth, and reliable operation across a wide temperature and voltage range.