OP37GP
OP37GP Operational Amplifier Technical Summary
Overview
The OP37GP is a precision high-speed operational amplifier that combines ultra-low noise performance with excellent speed and precision characteristics. As part of the OP27/OP37 family of operational amplifiers, it is specifically designed for applications requiring both low noise and high gain-bandwidth product. The OP37GP offers significant improvements over standard precision op-amps, particularly in noise performance and slew rate capabilities.
This device is the "GP" (general purpose) version of the OP37 series, providing balanced performance across all key parameters. The amplifier features laser-trimmed input circuitry for low offset voltage and drift, making it particularly suitable for precision instrumentation applications where signal integrity is critical.
Key Features
- Ultra-Low Noise Performance: 3.8 nV/√Hz at 1 kHz
- Excellent DC Precision: 25 µV maximum input offset voltage
- High Gain-Bandwidth Product: 63 MHz typical
- Fast Slew Rate: 17 V/µs minimum (OP37 series)
- Low 1/f Noise: 80 nV peak-to-peak (0.1 Hz to 10 Hz)
- High Open-Loop Gain: Minimum 1 V/µV
- Wide Supply Voltage Range: ±4V to ±18V operation
- Stable Operation: Unity gain stable (OP27) or optimized for gains ≥5 (OP37)
Applications
The OP37GP is ideally suited for a wide range of precision analog applications including:
- Professional audio equipment and high-fidelity systems
- Medical instrumentation and ECG amplifiers
- Seismic sensors and geophysical equipment
- High-resolution data acquisition systems
- Photodiode and transducer amplifiers
- Precision instrumentation and test equipment
- Low-noise preamplifiers for scientific applications
- Active filters with demanding noise requirements
Electrical Characteristics
All specifications are given for ±15V supplies at 25°C unless otherwise noted.
DC Characteristics
- Input Offset Voltage: 10 µV typical, 25 µV maximum
- Input Offset Voltage Drift: 0.2 µV/°C typical
- Input Bias Current: 40 nA typical, 80 nA maximum
- Input Offset Current: 20 nA typical, 40 nA maximum
- Common Mode Rejection Ratio (CMRR): 120 dB minimum
- Power Supply Rejection Ratio (PSRR): 110 dB minimum
- Large Signal Voltage Gain: 1,000,000 typical (1 V/µV minimum)
AC Characteristics
- Gain Bandwidth Product: 63 MHz typical
- Slew Rate: 17 V/µs minimum, 22 V/µs typical (OP37 series)
- Equivalent Input Noise Voltage:
- 3.8 nV/√Hz at 1 kHz
- 5.5 nV/√Hz at 10 kHz
- 0.1 Hz to 10 Hz Noise: 80 nV peak-to-peak typical
- Settling Time to 0.01%: 900 ns for 10V step
Power Characteristics
- Supply Voltage Range: ±4V to ±18V
- Quiescent Current: 5 mA typical per amplifier
- Operating Temperature Range: -40°C to +85°C
Package Information
The OP37GP is available in multiple package options to suit different application requirements:
8-Pin PDIP (Plastic Dual In-line Package)
- Package Code: P (DIP-8)
- Dimensions: 9.81mm x 6.35mm body
- Pin Spacing: 2.54mm (100 mil) between pins
- Lead Material: Copper alloy
- Lead Finish: Matte tin
- Moisture Sensitivity Level (MSL): MSL 1 (unlimited floor life)
8-Pin SOIC (Small Outline Integrated Circuit)
- Package Code: S (SOIC-8)
- Dimensions: 4.9mm x 3.9mm body
- Pin Spacing: 1.27mm (50 mil) between pins
- Lead Material: Copper alloy
- Lead Finish: Matte tin
- Moisture Sensitivity Level (MSL): MSL 1 (unlimited floor life)
Pin Configuration (8-Pin Packages)
- Pin 1: Offset Null
- Pin 2: Inverting Input (-IN)
- Pin 3: Non-Inverting Input (+IN)
- Pin 4: Negative Supply (-VEE)
- Pin 5: Offset Null
- Pin 6: Output
- Pin 7: Positive Supply (+VCC)
- Pin 8: NC (No Connection)
Design Considerations
Noise Optimization
To achieve the best noise performance from the OP37GP:
- Keep source impedances balanced at both inputs
- Use low-noise power supplies with adequate bypassing
- Minimize parasitic capacitances in the input circuit
- Use ground planes and proper board layout techniques
Stability Considerations
The OP37 is optimized for stable operation at closed-loop gains of 5 or greater. For gains below 5, consider:
- Using the OP27 variant which is unity-gain stable
- Adding small compensation capacitors if necessary
- Ensuring proper PCB layout to minimize stray capacitances
Thermal Management
While the OP37GP doesn't typically require heatsinking, consider:
- Using adequate copper area for power dissipation in high-temperature environments
- Allowing for proper air flow in densely packed designs
- Monitoring junction temperature in extreme operating conditions
