Texas Instruments OPA650U/2K5

Overview

OPA650U/2K5 from Texas Instruments (formerly Burr-Brown) is a unity-gain stable, low-power voltage-feedback operational amplifier optimized for high-speed video, imaging, and data acquisition systems. It delivers 560MHz closed-loop bandwidth at G = +1, 20ns 0.01% settling time, –77dBc harmonic distortion at 5MHz, ±2.3V output swing into 100Ω, and 85mA output current - enabling direct drive of 75Ω/100Ω video lines and ADC inputs.

For engineers reviewing the OPA650U/2K5 datasheet, OPA650U/2K5 pinout, OPA650U/2K5 application, or OPA650U/2K5 equivalent, key selection criteria include its 560MHz bandwidth with unity-gain stability, low 5µA input bias current, differential gain/phase error of 0.01%/0.03°, 240V/µs slew rate, and SO-8 package thermal resistance of 125°C/W - critical for portable, multi-channel, and high-resolution signal chain designs.

Technical Context

The OPA650U/2K5 employs a classical voltage-feedback architecture with fully symmetrical differential inputs, enabling precise active filter and instrumentation amplifier implementations. Its internal compensation ensures unity-gain stability with ~60° phase margin, and it maintains flat frequency response up to 560MHz in SO-8 packages when layout parasitics are minimized.

It operates from ±5V supplies (±4.5V to ±5.5V derated), supports common-mode input range of ±2.8V, achieves 73–77dBc spurious-free dynamic range at 5MHz, and delivers 12-bit settling in 20ns - making it suitable for telecommunication baseband, ultrasound signal processing, and CCD imaging front-ends where speed, linearity, and power efficiency are co-constrained.

Key Specifications

Pinout & Package

OPA650U/2K5 is housed in an 8-pin SOIC (SO-8) surface-mount package with θ_JA = 125°C/W, optimized for high-frequency PCB layouts requiring minimal parasitic capacitance on signal pins.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-speed op-amp applications.

Compared with OPA650U/2K5, OPA656U trades bandwidth for noise and DC precision, while LMH6629MA delivers extreme speed at the cost of stability and power - making OPA650U/2K5 uniquely balanced for unity-gain, low-power, high-fidelity video and imaging signal chains.

Availability

OPA650U/2K5 is available at Aetrix Electronics and suitable for high-resolution video systems, ultrasound beamformers, CCD imaging front-ends, and high-speed data acquisition requiring stable component supply across extended temperature ranges (–40°C to +85°C).

Supply support for OPA650U/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 (TI) is a global semiconductor leader specializing in analog and embedded processing technologies, with deep heritage in precision amplifiers dating to Burr-Brown's acquisition in 2000.

The OPA650U/2K5 belongs to TI's OPA high-speed voltage-feedback op-amp family, designed specifically for applications demanding simultaneous wide bandwidth, low distortion, and low power - including portable test equipment, medical imaging, and professional video infrastructure.

FAQ

What is the maximum capacitive load the OPA650U/2K5 can drive without oscillation?

The OPA650U/2K5 is nominally compensated for 2pF parasitic load and becomes unstable with >10pF capacitive loads unless isolated. For loads exceeding 10pF - such as flash ADC inputs or long PCB traces - a series isolation resistor (15Ω to 30Ω) must be placed directly at the output pin. This configuration preserves phase margin and prevents peaking or oscillation, as verified in TI's application note SBOS041.

Does the OPA650U/2K5 support single-supply operation?

Yes, the OPA650U/2K5 supports single-supply operation provided the input common-mode and output swing constraints are respected. With a +10V supply, the input common-mode range extends to ±2.8V relative to ground, and the output can swing to within ~2.2V of each rail. Figure 1 in the datasheet shows a practical single-supply configuration using resistive level-shifting and proper decoupling.

What is the thermal resistance (θ_JA) of the OPA650U/2K5 in its SO-8 package?

Per the official TI datasheet (SBOS041, page 2), the OPA650U/2K5 in SO-8 package has a junction-to-ambient thermal resistance (θ_JA) of 125°C/W under standard JEDEC 2-layer board conditions. This value assumes proper PCB copper pour and decoupling; actual θ_JA improves with enhanced thermal land patterns and internal plane layers.

Can the OPA650U/2K5 be used in a differential amplifier configuration?

Yes, the OPA650U/2K5 is explicitly listed under Applications as a "Differential Amplifier". Its fully symmetrical differential input stage, low input bias current (5µA), and high CMRR (≥65dB) make it well-suited for precision differential gain stages. When configured with matched resistors, it achieves excellent gain accuracy and rejection of common-mode noise in sensor interfaces and data acquisition front-ends.

Is the OPA650U/2K5 pin-compatible with other members of the OPA650 family?

The OPA650U/2K5 (SO-8) shares identical pinout with the OPA650P (DIP-8) and OPA650UB (SO-8, B-grade), including NC pins at 1, 7, and 8. However, it is not pin-compatible with the 5-pin SOT23-5 variants (OPA650N/NB), which use a different pin mapping and package footprint. Always verify package drawing D (SOIC-8) for OPA650U/2K5 layout compatibility.