LM258D - Dual Operational Amplifier

Overview

The LM258D is a dual operational amplifier designed for a wide range of analog applications. It consists of two independent, high-gain, internally frequency-compensated op-amps that operate from a single power supply over a wide voltage range. The device offers low power consumption and is suitable for battery-powered applications. Its performance characteristics make it ideal for transducer amplifiers, DC gain blocks, and other precision analog circuits.

Features

• Dual Operational Amplifier: Contains two independent op-amps in a single package.
• Wide Supply Voltage Range: Operates from 3V to 32V (±1.5V to ±16V in dual-supply configurations).
• Low Power Consumption: Quiescent current is typically 0.7mA per amplifier.
• Large Output Voltage Swing: Provides rail-to-rail output swing capability.
• Internally Frequency Compensated: No external compensation required for stable operation.
• Low Input Bias Current: Typically 20nA, making it suitable for high-impedance sensor applications.
• Common-Mode Input Voltage Range: Includes ground, allowing operation in single-supply applications.
• ESD Protection: Built-in protection against electrostatic discharge.

Applications

The LM258D is versatile and can be used in a variety of analog circuit designs, including:

• Transducer Amplifiers: Suitable for amplifying signals from sensors such as thermocouples, strain gauges, and pressure sensors.
• DC Gain Blocks: Provides precise amplification for low-frequency or DC signals.
• Active Filters: Can be used in low-pass, high-pass, and band-pass filter designs.
• Signal Conditioning: Ideal for conditioning signals in data acquisition systems.
• Battery-Powered Devices: Low power consumption makes it suitable for portable and handheld equipment.
• Voltage Followers: Used as buffer amplifiers to isolate stages in a circuit.
• Summing Amplifiers: Enables analog signal addition in mixer circuits.

Electrical Characteristics

The following table summarizes the key electrical specifications of the LM258D under typical operating conditions (V_CC = +5V, T_A = 25°C unless otherwise noted):

DC Characteristics

• Input Offset Voltage: 2mV (max)
• Input Bias Current: 20nA (typ)
• Input Offset Current: 2nA (typ)
• Common-Mode Rejection Ratio (CMRR): 85dB (typ)
• Supply Voltage Rejection Ratio (PSRR): 100dB (typ)
• Large-Signal Voltage Gain: 100V/mV (typ) at V_OUT = ±10V

AC Characteristics

• Gain Bandwidth Product: 1MHz (typ)
• Slew Rate: 0.5V/µs (typ)
• Input Noise Voltage: 40nV/√Hz (typ) at 1kHz

Power Supply Characteristics

• Supply Voltage Range: 3V to 32V (single supply), ±1.5V to ±16V (dual supply)
• Quiescent Current: 0.7mA per amplifier (typ)
• Output Short-Circuit Current: 40mA (max)

Package Information

The LM258D is available in multiple package options to accommodate different PCB layouts and assembly processes. The most common package is the SOIC-8 (Small Outline Integrated Circuit), which is surface-mountable and suitable for automated assembly.

SOIC-8 Package Dimensions

• Package Type: SOIC-8 (Surface Mount)
• Body Width: 3.9mm (max)
• Body Length: 4.9mm (max)
• Height: 1.75mm (max)
• Lead Pitch: 1.27mm

Pin Configuration

The pinout for the LM258D in an SOIC-8 package is as follows:

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

Thermal and Environmental Specifications

The LM258D is designed to operate reliably under various environmental conditions:

• Operating Temperature Range: -40°C to +125°C
• Storage Temperature Range: -65°C to +150°C
• Junction Temperature: 150°C (max)
• Thermal Resistance (θ_JA): 160°C/W (SOIC-8 package)

Conclusion

The LM258D is a highly versatile dual operational amplifier that combines low power consumption, wide supply voltage range, and robust performance in a compact package. Its internal frequency compensation eliminates the need for external components, simplifying circuit design. Whether used in battery-powered devices, signal conditioning circuits, or active filters, the LM258D delivers reliable and precise analog signal processing. Its availability in surface-mount packages makes it suitable for modern PCB designs, ensuring compatibility with automated assembly processes.