Texas Instruments OPA2137PA

Overview

OPA2137PA from Texas Instruments (formerly Burr-Brown) is a dual FET-input operational amplifier in an 8-pin DIP package, designed for precision, low-power, single- or dual-supply applications. It delivers 5pA input bias current, 1.5mV max input offset voltage, 1MHz gain-bandwidth, 3.5V/µs slew rate, and operates from ±2.25V to ±18V supplies - ideal for battery-powered instrumentation and photodetector amplification.

For engineers reviewing the OPA2137PA datasheet, OPA2137PA pinout, OPA2137PA application, or OPA2137PA equivalent, key selection criteria include its rail-to-rail input capability (extends to V+), low quiescent current (220µA/channel), wide temperature range (–40°C to +85°C), and independence between channels in dual configuration - critical for high-channel-density analog signal conditioning.

Technical Context

The OPA2137PA implements a JFET-input stage enabling ultra-low input bias current (5pA typ) and high input impedance (10¹² Ω || 2pF), supporting high-impedance sensor interfaces without significant loading. Its input common-mode range extends to the positive supply rail, eliminating need for level-shifting in single-supply configurations.

Each amplifier features fully independent circuitry with <0.6µV/V channel separation at DC, ensuring minimal crosstalk in dual-channel systems. The device is unity-gain stable and exhibits no phase inversion when inputs exceed common-mode limits - a reliability advantage over legacy FET op amps like TL061.

Key Specifications

Pinout & Package

OPA2137PA is housed in an 8-pin plastic dual in-line package (PDIP), pin-compatible with industry-standard 0.3-inch DIP footprints and compatible with through-hole prototyping and legacy PCBs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual FET-input operational amplifier applications.

Compared with TL072CP and OPA2340UA, the OPA2137PA uniquely balances ultra-low input bias current, rail-to-rail input capability, and sub-250µA/channel power - making it the preferred choice for precision, low-power, single-supply sensor front-ends where input impedance and battery life are co-critical.

Availability

OPA2137PA is available at Aetrix Electronics and suitable for strain gage amplifiers, photodetector interfaces, and precision integrators requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for OPA2137PA 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 maintains its legacy of high-precision analog ICs, emphasizing performance, reliability, and broad application coverage.

The OPA2137PA belongs to the MicroAmplifier™ series - engineered specifically for miniature, low-cost, high-accuracy analog signal conditioning in space-constrained and power-sensitive systems.

FAQ

What is the maximum capacitive load the OPA2137PA can drive without instability?

The OPA2137PA is specified to drive up to 1000pF capacitive loads while maintaining stability and phase margin. This capability eliminates the need for isolation resistors in many transimpedance amplifier configurations, such as photodiode interfaces with cable capacitance or PCB trace parasitics. For loads exceeding 1000pF, external compensation (e.g., feedback capacitor in parallel with gain-setting resistor) is recommended. The OPA2137PA's unity-gain stability ensures predictable behavior across this range without requiring additional external components in standard applications.

Does the OPA2137PA support single-supply operation, and what is the minimum supply voltage?

Yes, the OPA2137PA supports true single-supply operation from +4.5V to +36V. Its input common-mode range extends to the positive rail (V+), enabling direct sensing of signals referenced to V+ - such as high-side current monitoring. At minimum supply (+4.5V), inputs must remain ≥3V above V– (i.e., ≥3V above ground) for linear operation. The OPA2137PA's ability to operate down to ±2.25V dual supply (±4.5V total) makes it viable for low-voltage industrial and portable applications where other FET-input op amps fail to meet rail requirements.

How does channel separation in the OPA2137PA impact dual-channel designs?

The OPA2137PA guarantees ≤0.6µV/V (–124dB) DC channel separation, meaning a full-scale signal on Amplifier A induces less than 0.6µV of error at Amplifier B's output. This near-perfect isolation results from completely independent internal circuitry - no shared bias networks or substrate coupling. In practice, this enables simultaneous use of both amplifiers in multi-channel data acquisition without calibration interference, even during overload or short-circuit events on one channel. The OPA2137PA's channel separation exceeds that of most dual op amps in its class, including TL072 and CA3240.

Is the OPA2137PA susceptible to phase inversion when input voltages exceed the common-mode range?

No - the OPA2137PA is explicitly designed to avoid phase inversion, a failure mode common in older FET-input op amps like TL061. Even when input voltages exceed the specified common-mode range (e.g., driven beyond V+ or below V–+3V), the output remains monotonic and predictable. This robustness is critical in closed-loop systems such as voltage regulators or motor controllers where input overdrive may occur transiently. The OPA2137PA's input stage includes internal clamping diodes and optimized topology to maintain correct polarity under all operating conditions, as verified in the manufacturer's typical performance curves.

What thermal considerations apply to the OPA2137PA in 8-pin DIP packaging?

The OPA2137PA in PDIP package has a junction-to-ambient thermal resistance (θ_JA) of 100°C/W. At maximum quiescent current (270µA/channel × 2 = 540µA) and ±15V supply, total power dissipation is ~16.2mW, resulting in a worst-case junction temperature rise of 1.6°C above ambient - well within safe limits. No heatsinking is required for standard operation. However, in sealed enclosures above +70°C ambient, derating guidelines in the datasheet should be followed. The OPA2137PA's specified operating range (–40°C to +85°C) and storage rating (–55°C to +125°C) ensure reliability across industrial environments without thermal throttling or parameter drift.