Texas Instruments OPA548TG3

Overview

OPA548TG3 from Texas Instruments is a high-voltage, high-current operational amplifier designed for precision power amplification in demanding analog systems. It delivers ±3-A continuous output current, supports ±4 V to ±30 V dual supplies (or 8–60 V single supply), and features adjustable current limiting (0–5 A), thermal shutdown with status reporting, and output disable control. It is used in semiconductor test equipment, ultrasound scanners, and programmable lab power supplies.

For engineers reviewing the OPA548TG3 datasheet, OPA548TG3 pinout, OPA548TG3 application, or OPA548TG3 equivalent, key selection considerations include its 10 V/µs slew rate, ±2-mV input offset voltage, 7-pin TO-220 package with copper tab for heatsinking, and E/S pin dual functionality for enable/disable and thermal fault monitoring.

Technical Context

The OPA548TG3 uses a PNP-input stage with negative input bias currents and employs temperature-compensated class A/B output biasing to minimize crossover distortion. Its internal current-limit circuit senses load indirectly via the ILIM pin using a low-level control signal (0–330 µA), eliminating need for high-power series resistors.

It integrates an Enable/Status (E/S) pin that functions as both a TTL-compatible output disable input (logic low disables output in 1 µs) and an open-drain thermal shutdown status indicator (voltage drops from ~3.5 V to ~0.35 V above V– when junction exceeds 160°C). The device operates across –40°C to +85°C ambient with junction ratings up to 150°C.

Key Specifications

Pinout & Package

The OPA548TG3 is housed in a 7-lead TO-220 package (KVT/KC variant) with isolated copper tab for direct heatsink mounting. Thermal resistance is 30.2°C/W junction-to-ambient (R_θJA), and the tab is electrically connected to the V– pin.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-current operational amplifier applications.

Compared with OPA548TG3, OPA547T offers reduced performance and no E/S functionality, while LM675T lacks programmable current limiting and thermal status - both require additional external components to match OPA548TG3's integrated protection and control capabilities.

Availability

OPA548TG3 is available at Aetrix Electronics and suitable for semiconductor test equipment, ultrasound scanner subsystems, and programmable lab power supplies requiring stable component supply, long-term lifecycle support, and traceable industrial-grade sourcing.

Supply support for OPA548TG3 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 amplifiers and power management ICs.

The OPA548TG3 belongs to TI's high-voltage, high-current operational amplifier product line, engineered for applications demanding robust output drive, programmable protection, and thermal intelligence in test, medical, and industrial instrumentation.

FAQ

What is the maximum continuous output current specification for the OPA548TG3?

The OPA548TG3 delivers ±3 A continuous output current into resistive loads at specified operating temperatures. This rating assumes adequate heatsinking and adherence to Safe Operating Area (SOA) limits. Peak current capability reaches ±5 A for short durations, but sustained operation above ±3 A requires derating based on ambient temperature and thermal resistance. The OPA548TG3's current limit is user-adjustable from 0 A to 5 A via the ILIM pin, allowing precise control of maximum output regardless of load condition.

How does the E/S pin function in the OPA548TG3, and what design considerations apply?

The E/S pin on the OPA548TG3 serves dual roles: as an input to disable the output stage (pull ≤ (V–) + 0.8 V), reducing quiescent current to ±6 mA, and as an output indicating thermal shutdown (voltage drops to ~0.35 V above V– when junction exceeds 160°C). For reliable operation, tie the E/S pin to V– through a pull-down resistor in shutdown-only use, or monitor it with a comparator or MCU GPIO. Noise immunity can be improved with a small capacitor (e.g., 100 pF) between E/S and V– in electrically noisy environments. The OPA548TG3's E/S pin behavior is fully documented in Section 6.5 of its datasheet.

Can the OPA548TG3 operate from a single-ended supply, and what are the input common-mode limitations?

Yes, the OPA548TG3 supports single-supply operation from 8 V to 60 V, with input common-mode voltage extending to (V–) – 0.2 V - enabling ground-referenced inputs even when V– is tied to 0 V. The noninverting input (VIN+) accepts signals down to –0.2 V relative to V–, while the inverting input (VIN–) maintains linear operation across the same range. This makes the OPA548TG3 suitable for single-supply sensor interfaces and programmable voltage sources. However, output swing remains limited to within ~3.7 V of each rail at full load, so headroom must be allocated accordingly in single-supply designs using the OPA548TG3.

What thermal management requirements apply to the OPA548TG3 in continuous 3-A operation?

At ±3-A continuous output with ±30-V supplies, the OPA548TG3 can dissipate up to ~25 W. With a junction-to-ambient thermal resistance (R_θJA) of 30.2°C/W in the TO-220 package, ambient temperature must be kept below ~40°C without forced airflow or heatsinking. For reliable operation at 85°C ambient, a heatsink with R_θHA ≤ 2.5°C/W is required - such as Aavid Thermalloy 530002B02500G. Mounting the copper tab directly to a large metal chassis or heatsink (electrically isolated unless referenced to V–) is essential. The OPA548TG3's thermal shutdown activates at 160°C junction, providing fail-safe protection, but should not be relied upon for routine thermal management.

Is the OPA548TG3 pin-compatible with other members of the OPA54x family, and how does its current limit circuit differ from legacy alternatives?

The OPA548TG3 shares identical pinout and footprint with OPA547T and OPA549T in the 7-lead TO-220 package, enabling mechanical compatibility. However, only the OPA548TG3 integrates the dual-function E/S pin and precision ILIM-based current limiting. Unlike legacy amplifiers such as LM675T that require external sense resistors and discrete protection circuitry, the OPA548TG3 implements current limit sensing internally via a low-level control current (0–330 µA) on the ILIM pin - eliminating power loss and PCB area associated with high-wattage shunt resistors. This architecture is confirmed in TI's SBOS070D datasheet Figures 22 and 41.