Texas Instruments LM2676SX-5.0

Overview

LM2676SX-5.0 from Texas Instruments is a monolithic step-down (buck) DC-DC switching regulator delivering up to 3A output current with fixed 5.0V output, 260kHz fixed-frequency operation, ±2% output voltage tolerance over full line/load/temperature, and 8V–40V input range. It integrates a 150mΩ DMOS high-side switch and supports ON/OFF control for low-power standby mode.

For engineers reviewing the LM2676SX-5.0 datasheet, LM2676SX-5.0 pinout, LM2676SX-5.0 application, or LM2676SX-5.0 equivalent, key selection criteria include its 3A continuous load capability, thermal performance in TO-263 (KTW) package, efficiency up to 88% at 12V_IN/3A, and compatibility with standard off-the-shelf inductors and Schottky diodes in SIMPLE SWITCHER® designs.

Technical Context

The LM2676SX-5.0 implements a voltage-mode PWM controller with a fixed 260kHz oscillator and internal current-limit protection (3.6–5.4A). Its feedback loop uses a precision 1.21V reference and low-bias (85nA) error amplifier to regulate output directly-no external divider required for the 5.0V fixed version.

Thermal management relies on the exposed DAP (in KTW package) tied to PCB ground plane, enabling junction-to-ambient thermal resistance as low as 35°C/W with adequate copper area. Shutdown mode reduces quiescent current to 50µA via logic-level ON/OFF pin control with 0.8–2.0V threshold.

Key Specifications

Pinout & Package

LM2676SX-5.0 is supplied in the KTW (TO-263-7) thermally enhanced surface-mount package with an exposed DAP connected to GND for optimal heat dissipation. Package dimensions: 10.1mm × 15.24mm.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar step-down regulator applications.

Compared with LM2596SX-5.0 and TPS54302DDCR, the LM2676SX-5.0 uniquely combines 3A capability, 8–40V input support, fixed 5V output, and integrated high-side FET in a thermally optimized TO-263 package-making it the preferred choice for industrial and metering applications requiring robust, drop-in 5V conversion.

Availability

LM2676SX-5.0 is available at Aetrix Electronics and suitable for communication modules, electricity meters, and motor drive auxiliary supplies requiring stable component supply, long-term industrial lifecycle support, and guaranteed thermal performance in TO-263 packaging.

Supply support for LM2676SX-5.0 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, embedded processing, and power management technologies with decades of expertise in high-reliability power conversion ICs.

The LM2676 series belongs to TI's SIMPLE SWITCHER® portfolio-designed specifically for ease-of-use, minimal external component count, and robust performance in industrial, metering, and infrastructure power applications.

FAQ

What is the maximum input voltage rating for the LM2676SX-5.0?

The LM2676SX-5.0 has an absolute maximum input voltage rating of 45V, but its recommended operating input range is 8V to 40V DC. Operation beyond 40V risks exceeding safe operating area limits and may trigger internal protection or cause permanent damage. Always maintain input transient suppression within this window for reliable long-term use of the LM2676SX-5.0.

Does the LM2676SX-5.0 require external feedback resistors?

No-the LM2676SX-5.0 is the fixed 5.0V output variant, so internal resistor dividers set the output voltage. Pin 6 (FB) is internally connected to the output, eliminating the need for external resistors. This simplifies design, improves regulation accuracy, and avoids layout sensitivity associated with feedback node routing-key advantages of using the LM2676SX-5.0 over adjustable versions.

How does the ON/OFF pin function on the LM2676SX-5.0?

The ON/OFF pin (Pin 7) of the LM2676SX-5.0 controls device enable state: voltage <0.8V forces shutdown (50µA quiescent current), while >1.4V enables normal operation. An internal 20µA pull-up allows simple connection to VIN for always-on use. This pin supports system-level power sequencing and low-power sleep modes-critical for battery-backed applications using the LM2676SX-5.0.

What thermal performance can be expected from the LM2676SX-5.0 in its KTW package?

In the KTW (TO-263-7) package, the LM2676SX-5.0 achieves a junction-to-ambient thermal resistance (R_θJA) as low as 35°C/W when mounted on ≥0.4896 in² of 1 oz copper. With proper DAP grounding and thermal vias, it sustains 3A continuous output at ambient temperatures up to 85°C without forced air-validated by TI's thermal data for the LM2676SX-5.0 under real-world PCB conditions.

Can the LM2676SX-5.0 be used with standard off-the-shelf inductors?

Yes-the LM2676SX-5.0 is designed for compatibility with widely available 33µH shielded inductors from Renco, Pulse Engineering, and Coilcraft, as specified in TI's application notes. Its 260kHz fixed frequency and current-mode-like behavior simplify inductor selection; no custom magnetics are needed. This interoperability is a core benefit of the LM2676SX-5.0 in rapid prototyping and volume manufacturing.