OPA2227P - Dual Precision Low-Noise Op Amp | Texas Instruments
MPN: OPA2227P ✓ ActiveOPA2227P Overview
An operational amplifier is an analog integrated circuit that amplifies the voltage difference between its inverting and non-inverting inputs. Its place in the signal-chain hierarchy is operational amplifier → analog IC → semiconductor, while precision operation refers to maintaining accurate DC gain and offset behavior as well as low-distortion AC performance. The dual configuration provides two amplifiers in one package, reducing board area compared with two separate single-channel devices.
The OPA2227P combines low noise with wide bandwidth and high precision. The 3 nV/√Hz noise figure makes it relevant to sensor signals, instrumentation amplifiers, audio paths, and other applications in which input-referred noise limits usable resolution. Its 138 dB CMRR helps reject common-mode interference, while the 10 V/µs slew rate and 5 µs settling characteristics support faster closed-loop signal transitions than precision amplifiers with narrower bandwidth.
OPA2227 and OPA228 devices are identified by Texas Instruments as pin-for-pin replacements for industry-standard OP27 and OP37 devices. The OPA2227P therefore supports legacy precision-amplifier designs while offering a dual-channel implementation. Its internal characteristics are suited to both DC measurement and AC-coupled applications where low noise, stable gain, and common-mode rejection are important.
Typical uses include precision measurement front ends, low-level sensor amplifiers, buffered analog outputs, laboratory instrumentation, audio equipment, and active analog filters. The PDIP-8 package is suited to through-hole prototyping and designs where a mechanically robust package and readily visible connections are useful. Board-level compatibility still requires verification of supply voltage, input common-mode range, output swing, and stability configuration.
Design with the manufacturer datasheet as the controlling reference for maximum supply voltage, input bias current, offset voltage, open-loop gain, output-current capability, and recommended compensation. Place a short, low-impedance return from the power-supply pins to the ground plane, and provide adequate bypass capacitance close to the device. Avoid placing long copper traces beside sensitive input nets, and confirm that the selected gain and feedback network remain stable at the intended frequency.
This product record combines manufacturer ordering information, device-family positioning, precision and noise characteristics, practical application guidance, and drop-in replacement analysis. It helps engineers distinguish the PDIP OPA2227P from related single, dual, quad, and alternate-family variants before committing a PCB footprint or production release.
Drop-in alternatives for OPA2227P — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
OPA2228P
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
OPA2227P Maximum Ratings & Electrical Characteristics
| Amplifier Type | Dual precision operational amplifier |
| Number of Circuits | 2 circuits |
| Noise Density | 3 nV/√Hz |
| Slew Rate | 10 V/µs |
| Settling Time | 5 µs |
| Common-Mode Rejection | 138 dB |
| Unity-Gain Stability | Unity gain stable |
| Operating Temperature Range | -40°C to +85°C |
| Package | 8-pin PDIP (P) |
| Mounting Type | Through-hole |
OPA2227P 8-pin pdip (p) Pin Configuration Guide
Pin configuration for OPA2227P (8-pin pdip (p) package). This analog component features input, output, and power supply pins. Refer to the manufacturer datasheet for offset null, compensation, and enable pin configurations. Ideal for signal conditioning and amplifier circuits.
No detailed pinout data available for OPA2227P.
Refer to the datasheet for full pin configuration.
Typical Applications
OPA2227P is suitable for 6 applications: Precision Sensor Front Ends, Laboratory Instrumentation, Low-Noise Audio Preamplification, Industrial Control and Monitoring, Active Analog Filters, Data Acquisition and Analog Filtering.
Precision Sensor Front Ends
The OPA2227P fits low-level sensor conditioning because its specified 3 nV/√Hz noise limits the amplifier's contribution to the measured signal, while 138 dB common-mode rejection helps suppress interference shared by the input pair. Place the amplifier close to the sensor connector and preserve a compact, shielded return path to minimize pickup before the signal reaches filtering or conversion. The dual channel also allows related differential or reference signals to be conditioned with one package. Confirm the input common-mode range, bias-current error, and source-impedance limits from the manufacturer datasheet for the particular sensor and excitation scheme.
Recommended
Laboratory Instrumentation
OPA2227P is appropriate for laboratory instrumentation requiring low noise, high common-mode rejection, and precision closed-loop behavior. Its 3 nV/√Hz noise is valuable when the instrument amplifies small voltages from strain, temperature, or laboratory probes, while unity-gain stability provides a practical option for buffer and low-gain configurations. The 10 V/µs slew rate and 5 µs settling time support measurements that must capture rapid transitions without excessive delay. Layout should preserve high-impedance input symmetry and provide local supply bypassing, because otherwise board leakage and ground currents can dominate the low-noise performance of the amplifier itself.
Recommended
Low-Noise Audio Preamplification
The OPA2227P can serve in low-noise audio preamplifiers, line stages, and active filters where low input-referred noise and adequate dynamic response are required. Its 3 nV/√Hz noise helps establish a low amplifier-noise floor, while the 10 V/µs slew rate and 5 µs settling behavior provide useful margin when processing music or instrumentation signals. Unity-gain stability permits a straightforward voltage-follower configuration when the source impedance and loading are suitable. Verify output swing, load capability, and the frequency response of the selected feedback network so that the precision amplifier does not become the limiting element in the audio channel.
Recommended
Industrial Control and Monitoring
OPA2227P is suitable for industrial monitoring paths that combine slow process variables with occasional high-frequency interference. The 138 dB common-mode rejection helps reduce errors when both input terminals see a substantial common-mode voltage, while low noise preserves small-signal integrity. Its -40°C to +85°C specified operating range covers many industrial environments. Place the device away from switching nodes and motor-control traces, maintain balanced input routing, and use a single-point ground strategy for the sensitive analog section. Supply rails must remain within the datasheet limits, and any protection network should be checked for leakage, capacitance, and noise contributions.
Recommended
Active Analog Filters
OPA2227P can implement active filters and impedance stages that combine DC precision with low-noise AC performance. Unity-gain stability makes it useful in non-inverting and buffer-based topologies, while its 10 V/µs slew rate and 5 µs settling characteristics improve large-signal and transient behavior. Component tolerances in the feedback and gain-setting network should be considered carefully because precision DC operation and high closed-loop gain can magnify resistor errors and parasitic capacitance. Check the manufacturer datasheet for gain-bandwidth, open-loop gain, output swing, and stability limits before selecting the resistor and capacitor values for the target cutoff frequency.
Recommended
Data Acquisition and Analog Filtering
OPA2227P is appropriate for analog front-end stages that condition signals before an ADC or data-capture system. The low 3 nV/√Hz noise specification can improve the usable resolution of small sensor-derived waveforms, while unity-gain stability supports input buffering and moderate closed-loop gains. The dual channel permits simultaneous conditioning of a measurement input and its complementary or reference signal. Keep the amplifier close to the conversion stage, use low-leakage protection components where necessary, and account for settling time when the acquisition system changes gain or operating point. Confirm that the complete signal chain remains within the amplifier's common-mode and output-swing limits.
Recommended
Recommended Products Summary
Engineering reference data for OPA2227P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | OPA2228P |
|---|---|---|
| Package | 8-pin PDIP (P) | 8-pin PDIP (P) |
| Brand | Texas Instruments | Texas Instruments |
| Amplifier Channels | 2 circuits | 2 circuits |
| Mounting Type | Through-hole | Through-hole |
Key Differentiators
- Combines two precision amplifier channels with very low input noise (vs OPA2228P)
- Maintains strong common-mode interference rejection (vs OPA2228P)
- Provides a documented industry-standard replacement path (vs OPA2228P)
Design Notes
Place the recommended bypass capacitors immediately across the OPA2227P supply pins and their associated ground connections. Keep each capacitor-to-amplifier loop short, minimize the return-path length, and connect it to a low-impedance ground plane. This arrangement prevents fast supply-current changes from injecting noise through the amplifier's supply pins and helps preserve the benefit of the device's 3 nV/√Hz noise specification.
Route the two inputs symmetrically and keep them away from switching nodes, relay contacts, inductor windings, and high-current return paths. A short, guarded input trace reduces leakage and capacitive pickup that would otherwise appear above the amplifier's specified noise floor. Use a quiet analog ground region and connect measurement returns according to the system grounding architecture rather than creating long shared return paths between analog and power sections.
Do not assume that unity-gain stability permits every conceivable feedback network or load condition. Before finalizing the circuit, verify the intended closed-loop gain, capacitive loading, output swing, supply range, and common-mode range against the manufacturer datasheet. For precision DC measurements, also account for input bias current, offset voltage, and the resistance of the feedback network because those effects may dominate once the signal becomes very small.
For AC-coupled or high-frequency signal paths, use the smallest practical feedback resistors, maintain symmetrical input routing, and keep parasitic capacitance low around high-impedance nodes. The specified 10 V/µs slew rate and 5 µs settling time support fast operation, but actual bandwidth also depends on the amplifier's gain-bandwidth product and the closed-loop noise gain. Confirm stability with the final source impedance, load, and PCB geometry before release.
Compliance Information
The verified ordering and product-page information does not explicitly state the requested compliance statuses for OPA2227P.
