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Texas Instruments OPA2251UA
- Part No.:
- OPA2251UA
- Manufacturer:
- Texas Instruments
- Category:
- Instrumentation, Op Amps, Buffer Amps
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
OPA2251UA.pdf
- Description:
- IC OPAMP GP 2 CIRCUIT 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,730
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Product details
Overview
OPA2251UA from Texas Instruments is a dual-channel, micro-power operational amplifier optimized for ±15V supply operation, delivering 25μA quiescent current per amplifier, ±250μV max input offset voltage, rail-to-rail output swing within 50mV of rails, and 124dB common-mode rejection - used in portable medical instrumentation and battery-powered test equipment.
For engineers reviewing the OPA2251UA datasheet, OPA2251UA pinout, OPA2251UA application, or OPA2251UA equivalent, key selection considerations include its ±15V-optimized offset trim, dual-channel SOIC-8 package, unity-gain stability with capacitive loads up to 2700pF at ±15V, and operation across –40°C to +85°C industrial temperature range.
Technical Context
The OPA2251UA belongs to the OPAx251 family, laser-trimmed specifically at ±15V for low offset voltage (±50μV typ) and drift (±0.5μV/°C), while maintaining full functionality across ±1.35V to ±18V dual-supply or 2.7V–36V single-supply operation. Its input common-mode range extends 200mV below V–, enabling robust single-supply sensing.
It features unity-gain stability, rail-to-rail output (within 50mV at AOL > 100dB), high open-loop gain (128dB), and supports external offset trim via dedicated pins - a capability exclusive to the single (OPA251) and dual (OPA2251) variants, not quad versions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Range | ±1.35V to ±18V dual; 2.7V–36V single - enables flexible system-level power architecture without rail translation. |
| Quiescent Current | ±27μA typ per amplifier at ±15V - enables multi-year battery life in portable instruments. |
| Input Offset Voltage | ±50μV max at ±15V (25°C); ±100μV max over –40°C to +85°C - reduces DC error in precision sensor front-ends. |
| CMRR | 124dB min at ±15V - rejects noise from shared analog/digital grounds in mixed-signal systems. |
| Output Swing | Within 50mV of rails at AOL > 100dB and RL = 20kΩ - maximizes dynamic range in low-voltage data acquisition. |
| Gain-Bandwidth | 30kHz at ±15V - sufficient for DC-coupled signal conditioning and slow-control loops. |
| Input Bias Current | –4nA typ (flows out of inputs) - minimizes voltage error across high-impedance sensor sources like pH electrodes. |
Pinout & Package
OPA2251UA is housed in an 8-pin SOIC (D package), with exposed pad not present. Pin functions are validated per TI SBOS075A Figure 4-2 and Table 4-2.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| +IN A (Pin 3) | Noninverting input, Channel A | Accepts high-impedance analog signals; common-mode range extends to V– – 0.2V. |
| –IN A (Pin 2) | Inverting input, Channel A | Used for feedback configuration; matched with +IN A for precision differential gain. |
| OUT A (Pin 1) | Output, Channel A | Rail-to-rail capable; drives 20kΩ load while maintaining ≥100dB open-loop gain. |
| V– (Pin 4) | Negative power supply | Reference for both inputs and output; common-mode range defined relative to this pin. |
| +IN B (Pin 5) | Noninverting input, Channel B | Independent input path; enables dual-sensor monitoring or signal duplication. |
| –IN B (Pin 6) | Inverting input, Channel B | Supports independent gain-setting for second channel without crosstalk. |
| OUT B (Pin 7) | Output, Channel B | Electrically isolated from OUT A; channel separation < 0.3μV/V ensures minimal inter-channel interference. |
| V+ (Pin 8) | Positive power supply | Must be bypassed with 0.01μF ceramic capacitor near pin for stability with capacitive loads. |
Key Features
| Feature | Design Value |
|---|---|
| ±15V-optimized offset trim | Laser-trimmed at ±15V to achieve ±50μV typical offset - eliminates need for system-level calibration in high-voltage analog front-ends. |
| Rail-to-rail output | Swings within 50mV of V+ and V– at full open-loop gain - preserves signal headroom in low-supply industrial sensors. |
| Unity-gain stable | Drives up to 2700pF capacitive load at ±15V, G = 10 - supports direct connection to ADC input capacitors or long PCB traces. |
| External offset adjustment | Pins 1 and 5 provide trim access for Channel A and B - enables field recalibration in metrology-grade equipment. |
| Wide temperature range | Specified from –40°C to +85°C; functional from –55°C to +125°C - suitable for uncontrolled environmental deployments. |
Applications
| Battery-Powered ECG Monitor | Portable Multimeter Front-End |
|---|---|
Use Scenario: Amplifying low-amplitude biopotential signals (0.5–5mV) from dry electrodes under variable battery voltage (7–12V). IC Role / Device Role / Timing Role: Dual-channel instrumentation amplifier stage with matched gain and offset for differential lead I/II/III derivation. Use Value: 25μA quiescent current per channel extends battery life beyond 100 hours; ±250μV max offset ensures sub-μV baseline stability. |
Use Scenario: Conditioning DC voltage/current measurements across multiple ranges using programmable gain and auto-zeroing. IC Role / Device Role / Timing Role: Precision buffer and level-shifter between high-impedance DMM input and SAR ADC reference domain. Use Value: 124dB CMRR rejects switching noise from internal DC-DC converters; rail-to-rail output maximizes ADC utilization. |
| Low-Power Data Logger | Industrial Sensor Signal Chain |
Use Scenario: Continuous acquisition of thermistor, RTD, or strain gauge outputs in remote, solar-charged nodes. IC Role / Device Role / Timing Role: Single-supply (3.3V) signal conditioner with programmable gain and anti-alias filtering. Use Value: Input common-mode range down to V– – 0.2V allows direct connection to grounded sensors; 30kHz GBW supports oversampling. |
Use Scenario: Isolating and scaling 4–20mA loop signals in PLC analog input modules operating at ±15V. IC Role / Device Role / Timing Role: High-CMRR difference amplifier driving precision DAC or isolation amplifier inputs. Use Value: ±15V-optimized trim ensures < ±100μV offset drift over temperature - critical for 16-bit measurement accuracy. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-channel, micro-power op-amp applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| OPA2333AIDR | Zero-drift architecture (0.02μV/°C drift), 17μA IQ, 350kHz GBW - higher speed and lower drift, but no external trim pins. | Better for DC-critical applications like precision weight scales; less suitable where field recalibration is required. | Select OPA2333AIDR when long-term DC stability outweighs need for manual offset correction. |
| LMV358IDR | Higher IQ (150μA), 1MHz GBW, no trim capability, 7mV max VOS - lower precision, higher power, wider bandwidth. | Suitable for cost-sensitive consumer devices where micro-power and ultra-low offset are non-critical. | Select LMV358IDR only when budget constraints dominate and ±250μV offset is acceptable. |
Compared with OPA2251UA, OPA2333AIDR offers superior drift performance and bandwidth at lower quiescent current but lacks external trim; LMV358IDR trades precision and power efficiency for cost and speed - making OPA2251UA optimal for recalibratable, ±15V industrial signal chains.
Availability
OPA2251UA is available at Aetrix Electronics and suitable for battery-operated instruments, portable medical devices, and industrial test equipment requiring stable component supply across extended temperature and voltage ranges.
Supply support for OPA2251UA 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 company headquartered in Dallas, Texas, specializing in analog and embedded processing technologies with over 90 years of innovation in precision amplifiers and signal conditioning.
The OPAx251 product line was designed for high-accuracy, low-power analog signal conditioning in ±15V industrial and portable instrumentation - emphasizing laser-trimmed DC precision, rail-to-rail output, and robust capacitive-load drive.
FAQ
What supply voltage range does the OPA2251UA support?
The OPA2251UA operates from ±1.35V to ±18V dual supply or 2.7V to 36V single supply. It is laser-trimmed for optimal performance at ±15V, where it achieves ±50μV typical input offset voltage and ±0.5μV/°C drift. Performance remains functional across the full range, though offset and drift specifications degrade slightly outside ±15V - confirmed in TI SBOS075A Section 6.1.1. The OPA2251UA maintains rail-to-rail output swing and unity-gain stability throughout.
Does the OPA2251UA have external offset trim capability?
Yes, the OPA2251UA provides external offset trim capability on Pins 1 and 5 for Channel A and Channel B respectively, as documented in TI SBOS075A Section 6.1.2 and Figure 6-1. This feature allows field recalibration to null residual offset in high-accuracy applications such as metrology equipment. Trim is implemented using a 10kΩ potentiometer; however, excessive adjustment may degrade offset drift performance, so it is recommended only when initial offset exceeds system requirements.
What is the maximum capacitive load the OPA2251UA can drive stably?
The OPA2251UA drives up to 2700pF capacitively in unity-gain configuration at ±15V supply and G = 10, as shown in TI SBOS075A Figure 6-3. At lower supplies (e.g., ±1.35V), stability is maintained up to ~200pF without compensation. For larger loads at low voltage, a 5kΩ series resistor in the feedback path (Figure 6-4) extends stable operation beyond 1000pF - verified in typical characteristics and application notes. No external compensation is needed within specified limits.
Is the OPA2251UA unity-gain stable?
Yes, the OPA2251UA is explicitly designed and tested for unity-gain stability across its full operating range, including ±15V and 5V single-supply configurations. TI SBOS075A Section 6.1.3 confirms stability with capacitive loads up to 200pF at 5V/G=1 and 2700pF at ±15V/G=10. Its internal compensation ensures phase margin > 60° under all recommended conditions - eliminating need for external compensation networks in standard gain configurations.
What is the operating temperature range for the OPA2251UA?
The OPA2251UA is fully specified from –40°C to +85°C for electrical parameters including offset voltage, CMRR, and open-loop gain, per TI SBOS075A Section 5.2. It remains functional from –55°C to +125°C, though certain parameters (e.g., quiescent current, output swing) may deviate outside the specified range. Thermal metrics such as RθJA = 150°C/W (SOIC-8) ensure reliable operation in enclosed industrial enclosures without forced airflow.
OPA2251UA Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- microPOWER™
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Amplifier Type:
- General Purpose
- Number of Circuits:
- 2
- Output Type:
- Rail-to-Rail
- Slew Rate:
- 0.01V/µs
- Gain Bandwidth Product:
- 35 kHz
- -3db Bandwidth:
- -
- Current - Input Bias:
- 20 nA
- Voltage - Input Offset:
- 100 µV
- Current - Supply:
- 27µA (x2 Channels)
- Current - Output / Channel:
- 50 mA
- Voltage - Supply Span (Min):
- 2.7 V
- Voltage - Supply Span (Max):
- 36 V
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
OPA2251UA FAQ
1.How can I place an order for OPA2251UA through Aetrix?
Please submit a Request for Quotation (RFQ) for OPA2251UA 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 OPA2251UA reliable?
The price and inventory of OPA2251UA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for OPA2251UA is usually 5 days.
3.What payment methods are accepted for OPA2251UA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for OPA2251UA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for OPA2251UA?
OPA2251UA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your OPA2251UA 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 OPA2251UA?
For technical support, including OPA2251UA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your OPA2251UA requirements.
6.How does Aetrix verify that OPA2251UA is sourced from the original manufacturer or authorized distributors?
All OPA2251UA 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 OPA2251UA meets industry standards.
7.What is the process for return or replacement of OPA2251UA?
All OPA2251UA units undergo pre-shipment inspection (PSI). If there is an issue with OPA2251UA, 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 OPA2251UA part is unused and in its original packaging.
Return procedure for OPA2251UA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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