Texas Instruments LM2674LD-5.0/NOPB

Overview

LM2674LD-5.0/NOPB from Texas Instruments is a monolithic non-synchronous step-down DC-DC converter delivering 500mA at fixed 5.0V output, operating from 8–40V input with 260kHz fixed-frequency switching, ±1.5% output voltage tolerance, and integrated thermal/current protection. It serves as a primary power stage in industrial power supplies and embedded system rails.

For engineers reviewing the LM2674LD-5.0/NOPB datasheet, LM2674LD-5.0/NOPB pinout, LM2674LD-5.0/NOPB application, or LM2674LD-5.0/NOPB equivalent, key selection criteria include input voltage range (8–40V), guaranteed 500mA load capability, SOIC-8 package compatibility, 260kHz oscillator stability, and TTL-compatible ON/OFF control with 50μA standby current.

Technical Context

The LM2674LD-5.0/NOPB implements a LMDMOS-based buck topology with internal high-side DMOS switch (R_DS(ON) = 0.25Ω typ), bootstrap-driven gate control via CB pin, and voltage-mode regulation using a fixed 1.21V internal reference. Feedback is internally connected for fixed 5.0V operation-no external resistor divider required.

It operates in active mode above 1.4V on ON/OFF pin, enters low-power shutdown below 0.8V (typ), and includes cycle-by-cycle current limiting (0.62–1.2A), thermal shutdown, and frequency foldback under extreme overload-enabling robust operation without external protection circuitry.

Key Specifications

Pinout & Package

LM2674LD-5.0/NOPB is housed in an 8-pin SOIC (D) package (4.9mm × 6mm), optimized for thermal performance with exposed pad grounding not applicable-GND pins (6 and 7) provide primary thermal path. PCB layout requires short VIN-to-GND and VSW-to-inductor paths to minimize switching noise.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM2675SD-5.0/NOPB, the LM2674LD-5.0/NOPB offers proven legacy reliability and simpler design at slightly lower current/efficiency; versus TPS5430DDAR, it trades higher current and sync efficiency for lower component count and ease of use in 500mA-class applications.

Availability

LM2674LD-5.0/NOPB is available at Aetrix Electronics and suitable for industrial power supplies, embedded controller rails, automotive body electronics, and test equipment requiring stable component supply and long-term manufacturability.

Supply support for LM2674LD-5.0/NOPB 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 LM2674 series was designed as a SIMPLE SWITCHER® solution for cost-sensitive, medium-current DC-DC conversion - prioritizing ease of use, minimal external components, and rugged operation in industrial and automotive environments.

FAQ

What is the maximum input voltage rating for LM2674LD-5.0/NOPB?

The absolute maximum input voltage for LM2674LD-5.0/NOPB is 45V, with recommended operation from 8V to 40V. This wide range supports industrial 24V systems and automotive applications subject to load dump transients. Operation beyond 40V is permissible only for brief transients within the absolute max rating, and sustained operation above 40V may impact reliability or trigger protection circuits. Always verify input filtering and clamping in high-voltage environments.

Does LM2674LD-5.0/NOPB require external feedback resistors?

No, LM2674LD-5.0/NOPB does not require external feedback resistors. As a fixed 5.0V output variant, its internal feedback network is pre-configured - the FB pin (Pin 4) is internally connected to the regulation node. External connection of the FB pin is unnecessary and may disrupt regulation. This simplifies design, reduces component count, and eliminates resistor tolerance errors that affect output accuracy in adjustable versions.

What package type is used for LM2674LD-5.0/NOPB?

LM2674LD-5.0/NOPB uses the 8-pin SOIC (D) package, measuring 4.9mm × 6mm with standard gull-wing leads. It is not the WSON or PDIP variant - the "LD" suffix specifically denotes the SOIC-8 option. This package provides adequate thermal dissipation for 500mA operation with proper PCB copper area and does not include an exposed thermal pad, distinguishing it from leadless packages like WSON.

How does the ON/OFF pin function on LM2674LD-5.0/NOPB?

The ON/OFF pin (Pin 5) on LM2674LD-5.0/NOPB enables TTL-compatible control: applying ≥1.4V turns the regulator on, while ≤0.8V places it in low-power shutdown with 50μA typical quiescent current. The pin has an internal pull-up to 7V, so leaving it floating defaults to enabled operation. This allows direct interfacing with microcontrollers, logic gates, or manual switches without external biasing - critical for power sequencing and energy-saving modes.

What is the typical efficiency of LM2674LD-5.0/NOPB at full load?

LM2674LD-5.0/NOPB achieves 90% typical efficiency at 12V input, 5V/500mA output, per the official datasheet (Section 5.6). Efficiency varies with input voltage and load - e.g., ~86% at 12V_IN/3.3V_OUT and ~94% at 24V_IN/12V_OUT. The 0.25Ω R_DS(ON) switch and 260kHz fixed frequency contribute to this performance, and real-world results depend on external component selection (inductor DCR, diode VF, capacitor ESR) and PCB layout quality.