Texas Instruments OPA544T

Overview

OPA544T from Texas Instruments (originally Burr-Brown) is a high-voltage, high-current operational amplifier designed for direct drive of power loads including motors, actuators, and magnetic deflection coils. It delivers ≥2A continuous output current, operates from ±10V to ±35V supplies, and features 8V/µs slew rate, FET-input bias current ≤100pA, and thermal shutdown protection. It is used in programmable power supplies and servo amplifiers requiring robust output stage performance.

For engineers reviewing the OPA544T datasheet, OPA544T pinout, OPA544T application, or OPA544T equivalent, key selection criteria include safe operating area (SOA) compliance at elevated junction temperatures, output voltage swing under 2A load (e.g., (V+) –4.4V), thermal resistance θJC = 2.7°C/W (f > 50Hz), and compatibility with unbalanced supply configurations up to 70V total.

Technical Context

The OPA544T integrates high-performance JFET input circuitry with a monolithic high-power bipolar output stage, enabling precision control combined with high-current delivery. Its internal current limit (~4A at 25°C, decreasing with temperature) and thermal shutdown (triggering ~155°C) operate independently to protect against overload and sustained dissipation.

It supports non-inverting, inverting, and differential configurations with stable operation into complex loads when using recommended 1Ω + 0.01µF output series compensation. Common-mode input range extends to (V+) –4V and (V–) +4V, and open-loop gain exceeds 90dB at ±30V output into 1kΩ.

Key Specifications

Pinout & Package

The OPA544T uses a 5-lead TO-220 plastic package (package drawing KC) with the metal tab electrically connected to the V– supply pin for thermal and electrical grounding. Mounting requires mechanical attachment to a heatsink through the tab.

Key Features

Applications

Equivalent & Alternatives

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

Compared with OPA544T, OPA547T offers superior PSRR and identical thermal protection but consumes more quiescent power, while LM675T trades built-in thermal safety for higher absolute supply tolerance and lower cost - neither is pin-compatible, requiring layout revision.

Availability

OPA544T is available at Aetrix Electronics and suitable for motor driver designs, programmable power supplies, servo amplifier circuits, and magnetic deflection systems requiring stable component supply across extended industrial temperature ranges and high-reliability production cycles.

Supply support for OPA544T 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 high-performance analog portfolio. TI is a global semiconductor leader focused on analog, embedded processing, and connectivity solutions.

The OPA544T belongs to TI's Precision Power Operational Amplifiers product line, engineered for applications demanding both accuracy and high-output current - especially where integrated protection, thermal robustness, and wide supply flexibility are essential.

FAQ

What is the maximum safe continuous output current for OPA544T at 25°C case temperature?

The OPA544T delivers ≥2A continuous output current under specified conditions (TCASE = +25°C, VS = ±35V, RL = 15Ω). Its internal current limit is approximately 4A, but sustained 2A operation requires adequate heatsinking to maintain junction temperature ≤150°C. Derating applies above 25°C case temperature per the "Current Limit vs Temperature" curve - at 85°C case, safe continuous current drops to ~1.5A.

Does OPA544T support single-supply operation?

No, the OPA544T is designed exclusively for dual-supply operation (±10V to ±35V). Its input common-mode range requires at least 4V headroom from each rail, and the output cannot swing to either rail - minimum output voltage is (V–) +3.8V at 2A. For single-supply applications, consider TI's OPA567 or OPA569, which feature rail-to-rail output and dedicated single-supply biasing.

How is thermal protection implemented in OPA544T, and what triggers it?

The OPA544T incorporates thermal shutdown that activates at approximately 155°C junction temperature, protecting the die from permanent damage. It is triggered by excessive power dissipation due to high output current, large voltage drop across the output stage (VS–VO), insufficient heatsinking, or ambient temperature rise. Once triggered, the output disables until junction temperature falls below the hysteresis threshold (~145°C), and repeated cycling indicates inadequate thermal design.

Can OPA544T drive capacitive loads directly, or is external compensation required?

OPA544T requires external output-stage compensation for stable operation into capacitive or reactive loads. The datasheet recommends a 1Ω resistor in series with a 0.01µF capacitor between output and load. Without this network, complex load impedances (e.g., long cables, piezoelectric actuators, or deflection coils) may cause oscillation or ringing due to phase shift in the output stage's feedback loop.

What is the purpose of the metal tab on the OPA544T TO-220 package, and how should it be connected?

The metal tab on the OPA544T TO-220 package is electrically connected to Pin 1 (V–) and serves as the primary thermal conduction path to an external heatsink. It must be mounted to a grounded heatsink using thermally conductive insulating material (e.g., mica washer + thermal grease) if isolation is needed, or directly if V– is system ground. Improper mounting causes rapid junction temperature rise and premature thermal shutdown.