Texas Instruments OPA548T

Overview

OPA548T from Texas Instruments is a high-voltage, high-current operational amplifier designed for driving demanding resistive, capacitive, and reactive loads in precision power stages. It delivers ±3-A continuous output current, supports ±4 V to ±30 V dual supplies (or 8 V to 60 V single supply), and features adjustable current limiting (0–5 A), thermal shutdown with status indication, and output disable control - enabling use in programmable lab power supplies and semiconductor test fixtures.

For engineers reviewing the OPA548T datasheet, OPA548T pinout, OPA548T application, or OPA548T 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 heatsink mounting, and E/S pin dual functionality for enable/disable and thermal fault monitoring.

Technical Context

The OPA548T uses a PNP-input stage with negative input bias currents and no internal bias current compensation, requiring matched external input resistors to minimize offset errors. Its high-current output stage employs temperature-compensated class A/B biasing to reduce crossover distortion while maintaining stability into reactive loads.

Current limiting is implemented via indirect sensing at the ILIM pin, accepting a 0–330 µA control signal - eliminating series power resistors in the output path. The Enable/Status (E/S) pin provides both fast output disable (<1 µs) and open-drain thermal shutdown status reporting, supporting multiplexed multi-channel architectures up to 20 kHz.

Key Specifications

Pinout & Package

OPA548T is housed in a 7-lead TO-220 package (KVT/KC variants) with isolated copper tab for direct heatsink mounting and thermal performance of R_θJA = 30.2°C/W. The staggered or straight-lead configuration supports through-hole PCB assembly and mechanical stress relief.

Key Features

Applications

Equivalent & Alternatives

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

Compared with OPA547T and LM675T, the OPA548T uniquely integrates user-programmable current limiting, thermal status reporting, and fast output disable in a single 7-pin TO-220 package - reducing BOM count and board space while enhancing system-level safety and diagnostics.

Availability

OPA548T is available at Aetrix Electronics and suitable for semiconductor test fixtures, programmable lab power supplies, and ultrasound transducer drivers requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for OPA548T 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 company specializing in analog and embedded processing technologies, with leadership in precision amplifiers, data converters, and power management ICs.

The OPA548T belongs to TI's high-voltage, high-current operational amplifier product line, engineered for precision power delivery in test and measurement, industrial automation, and medical imaging systems.

FAQ

What is the maximum continuous output current specification for the OPA548T?

The OPA548T delivers ±3 A of continuous output current under recommended operating conditions. This rating assumes proper heatsinking and operation within the –40°C to +85°C ambient temperature range. Peak current capability reaches ±5 A for short durations, subject to safe-operating-area (SOA) constraints and thermal management. The actual sustained current depends on supply voltage, load impedance, and PCB thermal design - always verify against the SOA curve in the datasheet for your specific application.

How does the ILIM pin on the OPA548T set the current limit?

The ILIM pin on the OPA548T accepts a 0–330 µA control current that sets the output current limit from 0 A to 5 A using the equation I_LIM = (15000 × 4.75) / (13750 Ω + R_CL). Connecting a resistor R_CL between ILIM and V– establishes this current. For example, a 14.7-kΩ resistor yields ~2.5 A limit. Leaving ILIM open disables output (0 A); tying it directly to V– sets maximum limit (~5 A). This indirect sensing avoids power loss in the output path.

Can the OPA548T operate from a single-ended supply, and what is the input common-mode range?

Yes, the OPA548T operates from a single supply ranging from 8 V to 60 V. Its input common-mode voltage range extends below ground: down to (V–) – 0.2 V on the negative side and up to (V+) – 2.3 V on the positive side under linear operation. This allows direct interfacing with ground-referenced sensors or DACs without level-shifting circuitry - a key advantage in single-supply programmable power supply designs.

What is the function of the E/S pin on the OPA548T, and how is it used?

The E/S (Enable/Status) pin on the OPA548T serves two independent functions: pulling it to ≤(V–)+0.8 V disables the output stage (with <1 µs response) and reduces quiescent current to ±6 mA; monitoring its voltage reveals thermal shutdown status (drops from ~3.5 V to ~0.35 V above V– when junction exceeds 160°C). Both functions can be used simultaneously - e.g., microcontroller GPIO enables/disables channels while reading fault status on the same pin.

Does the OPA548T require external compensation for capacitive loads?

The OPA548T can drive moderate capacitive loads (e.g., ≤1000 pF) without external compensation, as verified in typical characteristics (Figure 19). However, for highly reactive or larger capacitive loads (>2 nF), or when operating near current limit, a series R/C snubber network (e.g., 10 Ω + 100 nF) at the output is recommended per Figure 38 to maintain phase margin and prevent oscillation. Stability must be validated under worst-case load and supply conditions in final layout.