Texas Instruments OPA137U/2K5

Overview

OPA137U/2K5 from Texas Instruments (formerly Burr-Brown) is a single-channel FET-input operational amplifier in SOIC-8 package, delivering 1MHz gain-bandwidth, 3.5V/µs slew rate, ±2.25V to ±18V dual-supply operation, and 5pA input bias current - ideal for precision photodetector amplification and battery-powered instrumentation.

For engineers reviewing the OPA137U/2K5 datasheet, OPA137U/2K5 pinout, OPA137U/2K5 application, or OPA137U/2K5 equivalent, key selection criteria include its rail-to-rail input capability (extends to V+), low 220µA quiescent current per channel, wide temperature range (–40°C to +85°C), and compatibility with single-supply systems requiring high input impedance and low offset drift.

Technical Context

The OPA137U/2K5 employs a JFET-input stage enabling ultra-low input bias current (5pA typ.) and high input impedance (10¹² Ω || 2pF), supporting precision DC-coupled signal conditioning. Its input common-mode range extends to the positive supply rail, eliminating need for level-shifting in high-side sensing applications.

It features unity-gain stability, 94dB open-loop gain, and excellent AC performance: 1MHz GBW with 3.5V/µs slew rate ensures fast settling (8µs to 0.1%) and minimal distortion (0.05% THD+N at 1kHz). The device operates reliably across ±2.25V to ±18V supplies and maintains specified performance from –40°C to +85°C.

Key Specifications

Pinout & Package

OPA137U/2K5 is housed in an 8-pin SOIC (SO-8) surface-mount package (Package Drawing D, JEDEC MS-012), with thermal resistance θ_JA = 150°C/W. This RoHS-compliant, green-qualified package supports reflow soldering per JEDEC Level-3 standards.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar FET-input op amp applications.

Compared with TLC27L2CDR and OPA313IDBVR, OPA137U/2K5 offers balanced performance: superior offset voltage (±1.5mV vs ±10mV) versus TLC27L2CDR, and proven robustness in industrial temperature ranges (–40°C to +85°C) versus newer micro-power alternatives that may lack extended qualification.

Availability

OPA137U/2K5 is available at Aetrix Electronics and suitable for precision instrumentation, photodetection systems, and battery-powered test equipment requiring stable component supply, long-lifecycle support, and consistent parametric performance across production batches.

Supply support for OPA137U/2K5 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 acquired Burr-Brown in 2000 and continues to manufacture, qualify, and support its precision analog portfolio including the OPA series.

The OPA137 belongs to TI's MicroAmplifier™ series - designed specifically for cost-sensitive, space-constrained applications demanding FET-input performance, low power, and broad supply flexibility without sacrificing precision.

FAQ

What is the maximum capacitive load the OPA137U/2K5 can drive without instability?

The OPA137U/2K5 is specified to drive up to 1000pF capacitive loads while maintaining stability and phase margin, as confirmed in the Absolute Maximum Ratings table and Typical Performance Curves. For loads exceeding 1000pF, external isolation (e.g., series resistor) or compensation network is required to prevent peaking or oscillation. This capability makes OPA137U/2K5 suitable for driving ADC input buffers and long-trace signal routing where parasitic capacitance accumulates.

Does the OPA137U/2K5 exhibit phase reversal when input voltage exceeds the supply rails?

No, the OPA137U/2K5 does not exhibit phase reversal when inputs exceed the supply rails - a key differentiator from older TL06x-family FET-input op amps. Its input stage is diode-clamped to V+ and V–, allowing safe overvoltage tolerance up to ±0.7V beyond rails. This behavior is explicitly documented in the Applications Information section and eliminates risk of latch-up or control-loop failure in voltage-follower configurations. Always limit input current to ≤2mA using series resistors if overvoltage exceeds 500mV beyond V–.

What is the operating temperature range for the OPA137U/2K5, and is it qualified for industrial use?

The OPA137U/2K5 is fully specified over –40°C to +85°C and operates across –55°C to +125°C, meeting industrial temperature grade requirements. All key parameters - including input offset voltage (±2.5mV max), input bias current (±100pA max), and open-loop gain (86dB min) - are guaranteed across the full –40°C to +85°C range. This qualification is confirmed in the SPECIFICATIONS table and PACKAGE/ORDERING INFORMATION section, making OPA137U/2K5 appropriate for factory automation, motor control, and outdoor instrumentation.

Can the OPA137U/2K5 be used in single-supply configurations, and what are the input voltage limitations?

Yes, the OPA137U/2K5 supports single-supply operation from +4.5V to +36V. Its input common-mode voltage range extends from (V–) + 3V to V+, meaning with V– = 0V (ground), inputs must remain ≥ +3V for linear operation. However, the input stage remains functional and non-inverting even below this threshold due to internal clamping. For true rail-to-rail input down to ground, external biasing (e.g., resistor divider) is recommended. This behavior is detailed in the "OPERATING VOLTAGE" and "INPUT VOLTAGE" subsections of the Applications Information.

What packaging and reel options are available for the OPA137U/2K5?

The OPA137U/2K5 is supplied in SOIC-8 (Package Drawing D) tape-and-reel format with 2500 units per reel (reel diameter 330mm, width 12.4mm, Q1 pin 1 quadrant). It is RoHS-compliant, green-qualified (no Sb/Br), with NIPDAU lead finish and JEDEC Level-3 moisture sensitivity rating (260°C peak, 168-hour floor life). This matches the ordering code suffix "/2K5" and is verified in TI's PACKAGE OPTION ADDENDUM and TAPE AND REEL INFORMATION tables.