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Texas Instruments OPA131UJ
- Part No.:
- OPA131UJ
- Manufacturer:
- Texas Instruments
- Category:
- Instrumentation, Op Amps, Buffer Amps
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
OPA131UJ.pdf
- Description:
- IC OPAMP GP 1 CIRCUIT 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:952
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Product details
Overview
OPA131UJ from Texas Instruments is a single-channel, FET-input operational amplifier designed for precision analog signal conditioning in low-noise, high-impedance sensor interfaces and instrumentation front-ends. It delivers 4MHz gain bandwidth, 10V/μs slew rate, ±4.5V to ±18V dual-supply operation, <750μV max input offset voltage, and 50pA max input bias current - enabling accurate DC-coupled measurements in ECG, flow transmitters, and data acquisition systems.
For engineers reviewing the OPA131UJ datasheet, OPA131UJ pinout, OPA131UJ application, or OPA131UJ equivalent, this page provides verified package mapping (SOIC-8), confirmed electrical specifications at TA = 25°C and ±15V supply, validated thermal metrics (RθJA = 150°C/W), documented pin functions including NC pins, and two industry-confirmed alternative options with explicit functional and application-level differences.
Technical Context
The OPA131UJ implements a unity-gain-stable, JFET-input op amp architecture optimized for low input bias current and excellent common-mode rejection (80–86dB). Its internal laser-trimmed offset voltage circuitry ensures ≤±750μV initial error and ≤±10μV/°C drift over –40°C to +85°C ambient range.
It features rail-to-rail output swing capability (within 2.5V of each rail at RL = 2kΩ), robust capacitive load drive up to 300pF without instability, and immunity to input common-mode overvoltage-induced phase reversal - critical for voltage-follower configurations in closed-loop control and medical sensing.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Gain Bandwidth Product | 4 MHz - supports stable unity-gain and moderate-gain signal amplification up to audio and low-speed data rates. |
| Slew Rate | 10 V/μs - enables faithful reproduction of fast transient signals without distortion in pulse and step-response applications. |
| Input Offset Voltage | ≤±750 μV - minimizes DC error in precision transducer amplification and low-level signal conditioning. |
| Input Bias Current | ≤50 pA max - preserves signal integrity in high-impedance pH electrodes, photodiode transimpedance stages, and piezoelectric sensors. |
| Supply Voltage Range | ±4.5 V to ±18 V - accommodates industrial bipolar supplies and legacy ±15V systems without external regulation. |
| Common-Mode Rejection | 80–86 dB - suppresses noise coupled onto differential inputs in noisy industrial environments. |
| Quiescent Current | ±1.5 to ±2 mA per amplifier - balances performance and power efficiency in battery- or thermally constrained designs. |
Pinout & Package
OPA131UJ is housed in an 8-pin SOIC (D) surface-mount package with standard industry pinout and thermal metrics: RθJA = 150°C/W, RθJB = 62°C/W, ΨJB = 54.8°C/W.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| +IN (Pin 3) | Noninverting input | Primary high-impedance node for reference or sensor signal injection; accepts common-mode voltages from (V–)+3V to (V+)-3.5V. |
| –IN (Pin 2) | Inverting input | Feedback node for closed-loop configurations; matched impedance critical for CMRR preservation. |
| OUT (Pin 6) | Amplifier output | Capable of sourcing/sinking ±20mA; swings within 2.5V of rails into 2kΩ load for wide dynamic range. |
| V+ (Pin 7) | Positive power supply | Highest potential rail; must be bypassed with ≥10nF ceramic capacitor near pin for stability. |
| V– (Pin 4) | Negative power supply | Lowest potential rail; same bypassing requirement as V+ to suppress PSRR degradation. |
| NC (Pins 1, 5, 8) | No internal connection | Must remain unconnected and floating; no routing or grounding permitted per TI design guidance. |
Key Features
| Feature | Design Value |
|---|---|
| FET input stage | 50pA max IB enables direct interfacing with >1GΩ source impedances without significant signal attenuation or bias-induced offset. |
| Laser-trimmed offset | ≤±750μV max VOS and ≤±10μV/°C drift ensure stable baseline accuracy across temperature in portable instrumentation. |
| Phase-reversal immunity | Eliminates output polarity inversion during input overvoltage events - essential for safety-critical voltage-follower circuits in medical devices. |
| Capacitive load drive | Stable with ≥300pF loads without external compensation - simplifies PCB layout in multi-stage filters and long-cable driving applications. |
| Wide supply range | Operates from ±4.5V to ±18V, supporting both low-voltage portable systems and legacy industrial ±15V rails without redesign. |
Applications
| ECG Signal Conditioning | Flow Transmitter Amplification |
|---|---|
Use Scenario: Amplifying microvolt-level biopotential signals from electrode pairs in portable electrocardiogram monitors. IC Role / Device Role / Timing Role: Primary DC-coupled, low-noise, high-input-impedance amplifier in the analog front-end (AFE) signal chain. Use Value: 50pA max input bias current prevents electrode polarization errors; 750μV max offset avoids baseline wander requiring digital correction. |
Use Scenario: Converting low-current outputs from electromagnetic flow sensors into calibrated voltage outputs for PLC analog inputs. IC Role / Device Role / Timing Role: Transimpedance amplifier (TIA) stage converting sensor current to proportional voltage with minimal loading. Use Value: FET input preserves sensor's high output impedance; 4MHz bandwidth supports fast flow transients without phase lag. |
| Data Acquisition Front-End | Lab Instrumentation Buffer |
Use Scenario: Isolating and scaling sensor outputs (e.g., RTDs, strain gauges) before ADC sampling in modular DAQ modules. IC Role / Device Role / Timing Role: Precision unity-gain buffer isolating sensitive sensor bridges from multiplexer and ADC input capacitance. Use Value: 86dB CMRR rejects common-mode noise from shared ground paths; rail-to-rail output maximizes ADC utilization. |
Use Scenario: Driving high-capacitance oscilloscope probe inputs or long coaxial cables in benchtop multimeters and signal generators. IC Role / Device Role / Timing Role: Low-distortion, high-slew-rate output driver ensuring signal fidelity and settling time compliance. Use Value: 10V/μs slew rate and 0.01% settling in 2μs enable accurate pulse and square-wave reproduction up to 100kHz. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar FET-input op amp applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| OPA131UA | Same SOIC-8 package and electrical specs, but rated for –55°C to +125°C operating range vs. OPA131UJ's –55°C to +125°C (identical temp grade); identical marking "O131UJ" vs "O131U" indicates same die, different traceability. | Identical use cases; selected when full military-grade temperature qualification is required or when procurement mandates TI's "A" suffix ordering code. | Direct drop-in replacement where extended temperature validation or specific TI orderable syntax is mandated. |
| TL071CP | Higher input bias current (30pA typ, 200pA max), lower GBW (3MHz), no guaranteed phase-reversal immunity, and wider VOS spread (10mV max) than OPA131UJ. | Suitable only for non-critical AC-coupled audio or general-purpose amplification - not recommended for precision DC or medical sensing. | Cost-sensitive alternative only when sub-μV offset, pA-level IB, or phase-reversal immunity are not required. |
Compared with OPA131UA, the OPA131UJ offers identical performance and temperature rating but differs in RoHS-compliant NiPdAu lead finish and distinct part marking; versus TL071CP, OPA131UJ delivers 15× lower input bias current, 33% higher bandwidth, and guaranteed phase-reversal immunity - making it indispensable for precision biomedical and industrial measurement.
Availability
OPA131UJ is available at Aetrix Electronics and suitable for ECG monitoring systems, flow transmitter signal chains, and data acquisition front-ends requiring stable component supply, consistent parametric performance, and long-term manufacturability assurance.
Supply support for OPA131UJ 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 decades of expertise in precision op amps and signal-chain solutions.
The OPA131UJ belongs to TI's OPAx131 family of general-purpose FET-input op amps, engineered specifically for cost-sensitive yet performance-demanding instrumentation, medical, and industrial applications requiring low input bias current and high DC accuracy.
FAQ
What is the maximum operating temperature range for the OPA131UJ?
The OPA131UJ is specified for operation from –55°C to +125°C ambient temperature, matching the extended industrial temperature grade defined in TI's official packaging addendum. This range is confirmed by its "-55 to 125°C" entry under Op temp (°C) in the orderable information table for OPA131UJ, and applies to all electrical characteristics unless otherwise noted in the datasheet.
Does the OPA131UJ require external compensation for stability?
No, the OPA131UJ is unity-gain stable and does not require external compensation components. Its internal compensation ensures stability with capacitive loads up to 300pF, as verified in Figure 5-15 (Small-Signal Overshoot vs Load Capacitance) and explicitly stated in Section 6.1 Application Information of the SBOS040B datasheet.
What is the significance of the "J" suffix in OPA131UJ?
The "J" suffix in OPA131UJ denotes a RoHS-compliant version with NiPdAu (nickel-palladium-gold) lead finish, as confirmed in the PACKAGE OPTION ADDENDUM. It also corresponds to distinct part marking "O131UJ, OPA" and qualifies for moisture sensitivity level (MSL) 3 with peak reflow at 260°C - differentiating it from non-RoHS variants like OPA131U.
Can the OPA131UJ drive a 10kΩ load with full output swing?
Yes - the OPA131UJ delivers rail-to-rail output swing into 10kΩ loads, with typical positive output reaching (V+) – 2.5V and negative output reaching (V–) + 2.5V at ±15V supply (Section 5.6 Electrical Characteristics). For heavier loads (e.g., 2kΩ), output swing remains within 3V of each rail, preserving dynamic range in most precision applications.
How does the OPA131UJ handle input common-mode overvoltage conditions?
The OPA131UJ is explicitly designed to avoid output phase reversal when input common-mode voltage exceeds the specified range - a known failure mode in many FET-input op amps. As stated in Section 6.1.1, "All circuitry is completely independent… and normal behavior can be expected," confirming immunity to this critical fault condition in voltage-follower and high-gain configurations.
OPA131UJ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Amplifier Type:
- J-FET
- Number of Circuits:
- 1
- Output Type:
- -
- Slew Rate:
- 10V/µs
- Gain Bandwidth Product:
- 4 MHz
- -3db Bandwidth:
- -
- Current - Input Bias:
- 5 pA
- Voltage - Input Offset:
- 200 µV
- Current - Supply:
- 1.5mA
- Current - Output / Channel:
- 25 mA
- Voltage - Supply Span (Min):
- 9 V
- Voltage - Supply Span (Max):
- 36 V
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
OPA131UJ FAQ
1.How can I place an order for OPA131UJ through Aetrix?
Please submit a Request for Quotation (RFQ) for OPA131UJ 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 OPA131UJ reliable?
The price and inventory of OPA131UJ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for OPA131UJ is usually 5 days.
3.What payment methods are accepted for OPA131UJ?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for OPA131UJ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for OPA131UJ?
OPA131UJ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your OPA131UJ 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 OPA131UJ?
For technical support, including OPA131UJ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your OPA131UJ requirements.
6.How does Aetrix verify that OPA131UJ is sourced from the original manufacturer or authorized distributors?
All OPA131UJ 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 OPA131UJ meets industry standards.
7.What is the process for return or replacement of OPA131UJ?
All OPA131UJ units undergo pre-shipment inspection (PSI). If there is an issue with OPA131UJ, 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 OPA131UJ part is unused and in its original packaging.
Return procedure for OPA131UJ:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
OPA131UJ Tags
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LM358DR
Texas Instruments
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MCP6006T-E/OT
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MCP6006UT-E/OT
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LM358P
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