MC3403 Quad Operational Amplifier

Overview

The MC3403 (and its counterpart MC3303) is a quad operational amplifier featuring four internally compensated, two-stage op-amps in a single package. Designed for versatility, this IC operates across a wide range of supply voltages, making it suitable for both single-supply and split-supply applications. The device employs a true differential input stage with class AB output architecture to minimize crossover distortion while maintaining robust performance characteristics.

Key to its design is the innovative two-stage architecture. The first stage incorporates differential input transistors (Q24/Q22) with input buffer transistors (Q25/Q21) and a differential-to-single-ended converter (Q3/Q4). This configuration not only provides initial gain but also handles level shifting and transconductance reduction - allowing the use of a small 5pF compensation capacitor while maintaining stability.

Features

• Robust Output Protection: Short-circuit protected outputs prevent damage during fault conditions
• High Quality Audio Performance: Class AB output stage minimizes crossover distortion
• Precision Input Stage: True differential input configuration for accurate signal processing
• Wide Supply Voltage Range:
  • Single supply operation: 3.0V to 36V
  • Split supply operation: ±1.5V to ±18V
• Low Power Consumption: Maximum input bias currents of 500nA
• High Integration: Four complete amplifiers in one package
• Stable Operation: Internally compensated for reliable performance
• Backward Compatible: Similar performance characteristics to MC1741C
• Standardized Implementation: Industry-standard pinouts for easy replacement
• Enhanced Durability: ESD protection diodes for improved ruggedness
• Environmental Compliance: Available in Pb-free package options

Applications

The MC3403's combination of features makes it ideal for a broad spectrum of applications:

• Power Supply Control Circuits: Voltage regulation and monitoring in DC/DC converters
• Industrial Control Systems: Signal conditioning for sensors and transducers
• Audio Processing: Preamplifiers and active filters benefiting from low distortion
• Medical Instrumentation: Biomedical signal amplification with high accuracy
• Automotive Electronics: Engine control units and sensor interfaces
• Consumer Electronics: Audio/video equipment and appliance controls
• Test and Measurement: Precision instrumentation circuits
• Battery-Powered Devices: Portable equipment benefiting from wide voltage range

Electrical Characteristics

The following table summarizes key electrical specifications (typical values at 25°C unless noted):

DC Characteristics

• Input Offset Voltage: 2.0mV maximum
• Input Bias Current: 45nA typical, 500nA maximum
• Input Offset Current: 5nA typical, 100nA maximum
• Common Mode Rejection Ratio (CMRR): 70dB typical
• Power Supply Rejection Ratio (PSRR): 100dB typical
• Large Signal Voltage Gain: 50V/mV typical at V_CC=15V, R_L=2kΩ

AC Characteristics

• Gain Bandwidth Product: 1.0MHz typical
• Slew Rate: 0.5V/μs typical
• Input Noise Voltage: 35nV/√Hz typical at 1kHz
• Phase Margin: 60° typical

Power Characteristics

• Supply Current (per amplifier): 0.8mA typical at V_CC=15V
• Output Current: 20mA minimum
• Output Short Circuit Current: 38mA typical

Package Information

The MC3403 is available in multiple package options to suit different application requirements:

Standard Package Options

• PDIP-14: Plastic Dual In-line Package (0.300" wide)
• SOIC-14: Small Outline Integrated Circuit (150 mil body width)
• TSSOP-14: Thin Shrink Small Outline Package (4.4mm body width)

Package Dimensions (PDIP-14)

• Total Length: 19.05mm (0.750")
• Body Width: 7.62mm (0.300")
• Lead Pitch: 2.54mm (0.100")
• Lead Length: 3.30mm (0.130") minimum

Thermal Characteristics

• Junction-to-Ambient Thermal Resistance (θ_JA):
  • PDIP-14: 80°C/W
  • SOIC-14: 160°C/W
• Maximum Junction Temperature: 150°C
• Operating Temperature Range: 0°C to +70°C (Commercial)

Design Considerations

When implementing the MC3403 in your designs, consider these important factors:

Power Supply Configuration

The device supports flexible power supply arrangements. For single supply operation (3V-36V), connect V_EE to ground. For split supply configurations (±1.5V to ±18V), maintain proper voltage relationships between V_CC and V_EE.

PCB Layout Guidelines

• Use proper bypass capacitors (0.1μF ceramic) close to power pins
• Maintain short lead lengths for high frequency stability
• Implement ground planes for noise reduction
• Keep sensitive inputs away from output traces

ESD Protection

While the device includes ESD protection diodes, additional precautions should be taken:

• Use proper handling procedures during assembly
• Consider additional protection for inputs exposed to external connections
• Implement current-limiting resistors for inputs in harsh environments