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Texas Instruments OPA251PA
- Part No.:
- OPA251PA
- Manufacturer:
- Texas Instruments
- Category:
- Instrumentation, Op Amps, Buffer Amps
- Package:
- 8-DIP (0.300", 7.62mm)
- Datasheet:
-
OPA251PA.pdf
- Description:
- IC OPAMP GP 1 CIRCUIT 8DIP
- Quantity:
- Payment:
- Shipping:
Inventory:4,517
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Product details
Overview
OPA251PA from Texas Instruments is a single-channel, micro-power operational amplifier optimized for ±15V dual-supply operation in precision analog signal conditioning. It delivers 25μA quiescent current, ±250μV max input offset voltage, rail-to-rail output swing within 50mV of rails, 124dB common-mode rejection, and 128dB open-loop gain-enabling high-accuracy, low-power sensing in portable medical instruments and battery-powered test equipment.
For engineers reviewing the OPA251PA datasheet, OPA251PA pinout, OPA251PA application, or OPA251PA equivalent, this page provides verified technical context, real-world design meaning for key specs, validated pin functions, application-specific implementation insights, and two confirmed alternative parts with documented functional and application-level differences.
Technical Context
The OPA251PA uses a precision bipolar input stage with laser-trimmed offset at ±15V, enabling stable DC accuracy across its full operating range (±1.35V to ±18V). Its unity-gain stability and capacitive load drive capability up to 2700pF at ±15V/10× gain support robust sensor interface and signal conditioning without external compensation.
Input common-mode range extends 200mV below V–, supporting single-supply configurations down to 2.7V, while rail-to-rail output ensures maximum dynamic range in low-voltage systems. Trim pins (1 and 5) allow external offset nulling-exclusive to the single-channel OPA251 and OPA241 variants.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Range | ±1.35V to ±18V dual supply; supports legacy ±15V industrial systems and extended-range instrumentation |
| Quiescent Current | ±27μA typical at ±15V; enables multi-year battery life in portable devices drawing <100μA total system current |
| Input Offset Voltage | ±50μV typical, ±250μV max at ±15V; eliminates need for user trimming in most precision DC-coupled applications |
| CMRR | 124dB at ±15V; rejects >99.999% of common-mode noise in noisy industrial environments |
| Open-Loop Gain | 128dB at ±15V; ensures <0.002% gain error in closed-loop configurations with gains ≤1000 |
| Output Swing | Within 50mV of rails at AOL > 100dB; preserves >99% of available voltage headroom for ADC interfacing |
| Gain-Bandwidth | 30kHz at ±15V; sufficient for DC–10kHz sensor signal conditioning with stable phase margin |
Pinout & Package
OPA251PA is housed in an 8-pin PDIP (Plastic Dual In-line Package) with 0.3-inch body width and through-hole mounting. Thermal resistance RθJA = 100°C/W enables operation up to +85°C ambient without forced airflow.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| +IN (3) | Noninverting input | High-impedance node (1GΩ || 4pF) accepting signals from high-Z sources like thermocouples or bridge sensors |
| –IN (2) | Inverting input | Differential input node; matched to +IN for CMRR performance; accepts feedback network connections |
| OUT (6) | Amplifier output | Rail-to-rail capable output driving 10kΩ loads; short-circuit protected (±21mA sink, +4mA source) |
| V+ (7) | Positive power supply | Highest potential rail; must be bypassed with 0.01μF ceramic capacitor near pin for stability |
| V– (4) | Negative power supply | Lowest potential rail; supports operation down to –18V; common-mode range extends 200mV below this pin |
| TRIM (1,5) | Offset voltage adjustment | External 20kΩ potentiometer connection points-only on single-channel versions-for fine-tuning DC accuracy |
| NC (8) | No internal connection | Floating terminal; no electrical function; may be left unconnected or tied to ground for mechanical stability |
Key Features
| Feature | Design Value |
|---|---|
| Laser-trimmed offset at ±15V | Ensures ±50μV typical VOS under target operating conditions-critical for factory-calibrated test equipment |
| Rail-to-rail output | Delivers full-scale signal swing to 12-bit+ ADCs without level-shifting circuitry, reducing BOM count and layout area |
| Unity-gain stable | Operates reliably in buffer, follower, and transimpedance configurations without external compensation components |
| Wide common-mode input range | Accepts inputs 200mV below V–, enabling direct interface to grounded-sensor topologies in single-supply systems |
| Low 1/f noise (1.7μVPP) | Minimizes drift-induced errors in DC-coupled medical instrumentation such as ECG front-ends and pressure transducers |
Applications
| Battery-Powered Test Equipment | Portable Medical Instrumentation |
|---|---|
Use Scenario: Handheld multimeter front-end amplifying mV-level thermocouple or shunt voltage signals. IC Role / Device Role / Timing Role: Precision DC-coupled gain stage with ultra-low input bias current and offset drift. Use Value: Enables 4½-digit resolution without auto-zero circuitry, extending battery life beyond 100 hours per AA cell pair. |
Use Scenario: Low-noise signal conditioning for wearable pulse oximeter photodiode current detection. IC Role / Device Role / Timing Role: Transimpedance amplifier converting nanoamp photocurrents into clean voltage outputs. Use Value: 1.7μVPP 0.1–10Hz noise and ±250μV offset ensure SpO₂ saturation accuracy within ±1% across temperature. |
| Industrial Sensor Signal Conditioning | Low-Power Data Acquisition Modules |
Use Scenario: 4–20mA loop-powered transmitter amplifying RTD or strain gauge bridge outputs. IC Role / Device Role / Timing Role: High-CMRR differential amplifier rejecting common-mode noise from motor drives and PLCs. Use Value: 124dB CMRR suppresses >99.999% of 50/60Hz interference, eliminating need for additional filtering stages. |
Use Scenario: Remote environmental monitoring node digitizing temperature/humidity sensor outputs. IC Role / Device Role / Timing Role: Rail-to-rail output buffer isolating precision ADC reference from varying load conditions. Use Value: 50mV rail margin ensures full 0–3.3V ADC input range utilization even at end-of-battery-life voltages. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar precision op-amp applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| OPA241PA | Optimized for 5V single supply; ±100μV max VOS at 5V vs. ±250μV at ±15V for OPA251PA | Better suited for modern 3.3V/5V battery systems; lower PSRR at high frequencies than OPA251PA | Select OPA241PA when operating from 2.7–5V supplies and prioritizing lowest possible quiescent current (±25μA) |
| TLV2461CP | Rail-to-rail I/O; 600μA IQ; 2.5mV max VOS; 6.4MHz GBW-higher speed but 24× higher power | Used in higher-bandwidth sensor interfaces where micro-power is secondary to response time | Choose TLV2461CP only when >100kHz signal bandwidth is required and battery life is not constrained |
Compared with OPA241PA and TLV2461CP, the OPA251PA uniquely balances ±15V compatibility, sub-30μA quiescent current, and <250μV offset-making it the sole choice for legacy industrial test gear requiring both high-voltage headroom and multi-year battery operation.
Availability
OPA251PA is available at Aetrix Electronics and suitable for battery-operated instruments, portable medical devices, and industrial sensor signal conditioning requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for OPA251PA includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Texas Instruments is a global semiconductor leader specializing in analog and embedded processing technologies, with over 50 years of precision amplifier innovation.
The OPAx251 family was designed specifically for high-accuracy, low-power analog signal conditioning in ±15V industrial and portable instrumentation-prioritizing DC precision, rail-to-rail output, and thermal stability over speed.
FAQ
What is the maximum supply voltage rating for the OPA251PA?
The OPA251PA has an absolute maximum supply voltage of ±18V (36V total), with recommended operation from ±1.35V to ±18V. At ±15V, it achieves optimal offset voltage and drift performance per TI's laser-trimming specification. Exceeding ±18V risks permanent damage per Section 5.1 Absolute Maximum Ratings.
Does the OPA251PA support single-supply operation?
Yes, the OPA251PA operates from a single supply of 2.7V to 36V. Its input common-mode range extends 200mV below V–, and output swings rail-to-rail within 50mV-enabling true single-supply use in systems like 3.3V data loggers. However, offset voltage is specified and trimmed for ±15V, so VOS may increase slightly at low voltages.
What is the purpose of pins 1 and 5 on the OPA251PA?
Pins 1 and 5 are dedicated offset voltage trim terminals, available only on the single-channel OPA251PA and OPA241PA. They accept a 20kΩ potentiometer to null residual input offset-useful in ultra-high-precision applications where ±250μV max is insufficient. TI cautions that trimming may degrade offset drift performance.
Can the OPA251PA drive large capacitive loads?
Yes-the OPA251PA drives up to 2700pF capacitively at ±15V with gain ≥10, per Figure 6-3. At unity gain and ±15V, stability is maintained up to ~500pF. For larger loads, TI recommends adding a series resistor (e.g., 5kΩ) inside the feedback loop, as shown in Figure 6-4, to preserve stability without sacrificing DC accuracy.
How does the OPA251PA compare to the OPA241PA in terms of offset voltage?
The OPA251PA is laser-trimmed at ±15V and specifies ±50μV typical / ±250μV max VOS under those conditions. The OPA241PA is trimmed at 5V and specifies ±50μV typical / ±250μV max at 5V-but its VOS degrades to ±150μV max at ±15V. Thus, OPA251PA maintains superior DC accuracy in ±15V systems.
OPA251PA Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 8-DIP (0.300", 7.62mm)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Amplifier Type:
- General Purpose
- Number of Circuits:
- 1
- Output Type:
- Rail-to-Rail
- Slew Rate:
- 0.01V/µs
- Gain Bandwidth Product:
- 35 kHz
- -3db Bandwidth:
- -
- Current - Input Bias:
- 4 nA
- Voltage - Input Offset:
- 50 µV
- Current - Supply:
- 27µA
- Current - Output / Channel:
- 21 mA
- Voltage - Supply Span (Min):
- 2.7 V
- Voltage - Supply Span (Max):
- 36 V
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 8-PDIP
OPA251PA FAQ
1.How can I place an order for OPA251PA through Aetrix?
Please submit a Request for Quotation (RFQ) for OPA251PA on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for OPA251PA reliable?
The price and inventory of OPA251PA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for OPA251PA is usually 5 days.
3.What payment methods are accepted for OPA251PA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for OPA251PA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for OPA251PA?
OPA251PA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your OPA251PA order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for OPA251PA?
For technical support, including OPA251PA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your OPA251PA requirements.
6.How does Aetrix verify that OPA251PA is sourced from the original manufacturer or authorized distributors?
All OPA251PA products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that OPA251PA meets industry standards.
7.What is the process for return or replacement of OPA251PA?
All OPA251PA units undergo pre-shipment inspection (PSI). If there is an issue with OPA251PA, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The OPA251PA part is unused and in its original packaging.
Return procedure for OPA251PA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
OPA251PA Tags
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LM358DT
STMicroelectronics
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LM358DR
Texas Instruments
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LM2904DR
Texas Instruments
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LM358ADR
Texas Instruments
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LM2904DGKR
Texas Instruments
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MCP6006T-E/OT
Microchip Technology
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MCP6006UT-E/OT
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LM324PWR
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LM2902PWR
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LM2902DR
Texas Instruments
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LM358P
Texas Instruments
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