MC1458

MC1458 Dual Operational Amplifier Technical Summary

Overview

The MC1458 is a high-performance, monolithic dual operational amplifier designed for a wide range of analog applications. This IC integrates two independent op-amps in a single package, offering excellent performance with low power consumption and robust electrical characteristics. The device is well-suited for both general-purpose and precision analog circuits, featuring high gain, wide input voltage range, and built-in short-circuit protection.

Key Features

• Low Power Consumption: Optimized for energy-efficient operation, making it suitable for battery-powered devices.
• Large Input Voltage Range: Supports a broad range of input signal levels, enhancing versatility in various circuit configurations.
• No Latch-Up: Designed to prevent latch-up under abnormal operating conditions, ensuring reliable performance.
• High Gain: Delivers high open-loop voltage gain, making it ideal for precision amplification tasks.
• Short-Circuit Protection: Built-in safeguards protect the device from damage during output short-circuit conditions.
• No Frequency Compensation Required: Internally compensated for stable operation without external components.

Applications

The MC1458 is widely used in both industrial and consumer electronics due to its robust performance and flexibility. Key application areas include:

• Summing Amplifier: Combines multiple input signals into a single output with precise weighting.
• Voltage Follower: Provides high input impedance and low output impedance for signal buffering.
• Integrator: Used in analog computing and waveform generation circuits.
• Active Filtering: Implements low-pass, high-pass, band-pass, and notch filters with minimal external components.
• Function Generator: Generates sine, square, and triangular waveforms in oscillator circuits.

Electrical Characteristics

The following table summarizes the key electrical specifications of the MC1458 under typical operating conditions (unless otherwise noted):

• Supply Voltage Range: ±3V to ±18V (Dual Supply)
• Input Offset Voltage: 2mV (max)
• Input Bias Current: 500nA (max)
• Input Offset Current: 100nA (max)
• Open-Loop Gain: 100dB (typical)
• Common-Mode Rejection Ratio (CMRR): 90dB (typical)
• Power Supply Rejection Ratio (PSRR): 100dB (typical)
• Slew Rate: 0.5V/µs (typical)
• Bandwidth: 1MHz (typical)
• Output Current: 20mA (short-circuit protected)

Package Information

The MC1458 is available in multiple package options to accommodate different PCB layouts and assembly processes. The most common packages include:

• 8-Pin PDIP (Plastic Dual In-Line Package):
  • Dimensions: 9.81mm x 6.35mm
  • Pin spacing: 2.54mm (standard DIP spacing)
• 8-Pin SOIC (Small Outline Integrated Circuit):
  • Dimensions: 4.90mm x 3.90mm
  • Pin spacing: 1.27mm

Pin Configuration

The pinout for the MC1458 (8-pin package) is as follows:

• Pin 1: Output A (Amplifier 1 Output)
• Pin 2: Inverting Input A (Amplifier 1 Inverting Input)
• Pin 3: Non-Inverting Input A (Amplifier 1 Non-Inverting Input)
• Pin 4: V- (Negative Power Supply)
• Pin 5: Non-Inverting Input B (Amplifier 2 Non-Inverting Input)
• Pin 6: Inverting Input B (Amplifier 2 Inverting Input)
• Pin 7: Output B (Amplifier 2 Output)
• Pin 8: V+ (Positive Power Supply)

Design Considerations

When designing with the MC1458, consider the following guidelines to ensure optimal performance:

• Power Supply Decoupling: Use 0.1µF ceramic capacitors close to the power supply pins to minimize noise.
• Thermal Management: Although the MC1458 has low power dissipation, ensure adequate ventilation in high-temperature environments.
• Input Protection: For applications with large input differential voltages, consider adding external clamping diodes.
• PCB Layout: Keep signal traces short and avoid parallel routing of input and output traces to prevent feedback oscillations.

Conclusion

The MC1458 dual operational amplifier is a versatile and reliable component for a wide range of analog signal processing applications. Its combination of low power consumption, high gain, and robust protection features make it an excellent choice for both novice and experienced designers. Whether used in active filters, integrators, or voltage followers, the MC1458 delivers consistent performance across diverse operating conditions.