OP400

OP400 Quad Operational Amplifier Technical Summary

Overview

The OP400 is a groundbreaking monolithic quad operational amplifier that delivers OP77-type precision performance in a space-efficient, cost-effective package. As the first of its kind, it eliminates the traditional trade-off between precision and space/cost savings in quad op-amp designs. The OP400 combines four high-performance amplifiers in a single IC, making it ideal for applications requiring multiple precision amplifiers while conserving board space and reducing component count.

Key Features

• Low input offset voltage: 150μV maximum
• Exceptional offset voltage drift: 1.2μV/°C maximum over -55°C to +125°C range
• Low power consumption: 725μA maximum supply current per amplifier
• High open-loop gain: 5000V/mV minimum
• Low input bias current: 3nA maximum
• Excellent noise performance: 11nV/√Hz noise voltage density at 1kHz
• Stable with large capacitive loads (10nF typical)
• Pin-compatible with LM148, HA4741, RM4156, and LT1014 with improved performance
• Available in die form for specialized applications

Applications

The OP400's combination of precision and quad packaging makes it suitable for a wide range of applications:

• Precision instrumentation amplifiers
• Data acquisition systems
• Medical instrumentation
• Industrial control systems
• Test and measurement equipment
• Analog signal processing
• Active filters
• Voltage followers
• Summing amplifiers
• Integrators and differentiators

Electrical Characteristics

The following table summarizes the key electrical specifications of the OP400:

DC Characteristics (V_S = ±15V, T_A = 25°C unless otherwise specified)

• Input Offset Voltage: 150μV max
• Input Offset Voltage Drift: 1.2μV/°C max (-55°C to +125°C)
• Input Bias Current: 3nA max
• Input Offset Current: 1nA max
• Common Mode Rejection Ratio: 110dB min
• Power Supply Rejection Ratio: 110dB min
• Large Signal Voltage Gain: 5000V/mV min (R_L ≥ 2kΩ)
• Supply Current (per amplifier): 725μA max
• Output Voltage Swing: ±13V min (R_L ≥ 2kΩ)

AC Characteristics

• Gain Bandwidth Product: 500kHz typ
• Slew Rate: 0.15V/μs typ
• Input Voltage Noise: 11nV/√Hz at 1kHz
• Input Current Noise: 0.5pA/√Hz at 1kHz
• Phase Margin: 60° typ (C_L = 10nF)

Absolute Maximum Ratings

• Supply Voltage: ±22V
• Input Voltage: ±22V
• Differential Input Voltage: ±30V
• Output Short-Circuit Duration: Continuous
• Operating Temperature Range: -55°C to +125°C
• Storage Temperature Range: -65°C to +150°C

Package Information

The OP400 is available in multiple package options to suit different application requirements:

Standard Package Options

• 14-Lead Hermetic Ceramic DIP (D14)
• 14-Lead Plastic DIP (P14)
• 16-Lead SOIC (S16)
• Die Form (for hybrid applications)

Pin Configuration (14-Lead DIP/SOIC)

• Pin 1: Output A
• Pin 2: Inverting Input A
• Pin 3: Non-Inverting Input A
• Pin 4: V+
• Pin 5: Non-Inverting Input B
• Pin 6: Inverting Input B
• Pin 7: Output B
• Pin 8: Output C
• Pin 9: Inverting Input C
• Pin 10: Non-Inverting Input C
• Pin 11: V-
• Pin 12: Non-Inverting Input D
• Pin 13: Inverting Input D
• Pin 14: Output D

Design Considerations

When implementing the OP400 in circuit designs, consider the following:

Power Supply Decoupling

Proper power supply decoupling is essential for optimal performance. Place 0.1μF ceramic capacitors as close as possible to each power supply pin, with a 1-10μF tantalum capacitor for bulk decoupling.

PCB Layout

For best performance:

• Keep input traces short and away from output traces
• Use ground planes to minimize noise pickup
• Match impedance of differential input traces
• Minimize stray capacitance at high impedance nodes

Thermal Considerations

While the OP400 has excellent thermal characteristics, in high-density quad amplifier applications, ensure adequate airflow or heat sinking if operating at high ambient temperatures.

Performance Advantages

The OP400 offers several significant advantages over competing quad operational amplifiers:

• Superior precision compared to standard quad op-amps
• Lower noise characteristics than typical quad amplifiers
• Better drift performance over temperature
• Higher open-loop gain for improved accuracy
• Lower power consumption than precision discrete alternatives
• Proven stability with capacitive loads up to 10nF

Conclusion

The OP400 represents a significant advancement in quad operational amplifier technology, bringing precision performance previously only available in single op-amps to space-saving quad packages. Its combination of low offset voltage, excellent drift characteristics, low noise, and high gain make it an ideal choice for demanding analog applications where multiple amplifiers are required. The OP400's pin compatibility with industry-standard quad op-amps allows for easy upgrades to higher performance in existing designs.