Texas Instruments LM2575N-5.0/NOPB

Overview

LM2575N-5.0/NOPB from Texas Instruments is a monolithic 1A step-down (buck) switching voltage regulator in a 5-lead TO-220 package, delivering a fixed 5.0V ±4% output across 8V–40V input, with 52 kHz fixed-frequency operation, thermal shutdown, and cycle-by-cycle current limiting. It replaces linear regulators in board-level DC/DC conversion for industrial power supplies.

For engineers reviewing the LM2575N-5.0/NOPB datasheet, LM2575N-5.0/NOPB pinout, LM2575N-5.0/NOPB application, or LM2575N-5.0/NOPB equivalent, key selection considerations include its 1A continuous output capability, 77% efficiency at 12V_IN/1A, TTL-compatible shutdown, and requirement for only four external components - inductor, catch diode, and input/output capacitors.

Technical Context

The LM2575N-5.0/NOPB integrates a PWM controller, power switch, oscillator, error amplifier, and protection circuitry into a single silicon die. Its internal 52 kHz oscillator sets the switching frequency, enabling use of standard off-the-shelf inductors (e.g., 330 µH for 5V output), while the feedback loop regulates output via internal 1.23V reference and comparator.

Operation relies on external components: a Schottky catch diode (e.g., SR103), an aluminum electrolytic input capacitor (≥47 µF, 25V), and output capacitor (≥330 µF, 25V). The device enters low-power standby (50 µA typical) when the ON/OFF pin is pulled high, and features built-in thermal shutdown and peak current limit (1.7–3.0 A).

Key Specifications

Pinout & Package

LM2575N-5.0/NOPB uses a 5-lead TO-220 package (package number NDH0005D) with vertical mounting and bent, staggered leads. The exposed tab is electrically connected to Pin 2 (Output) and serves as the primary thermal path to the PCB copper area.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar buck regulator applications.

Compared with LM2575T-5.0, LM2575N-5.0/NOPB offers identical regulation and thermal behavior but with bent/staggered leads optimized for manual assembly and heatsink contact. Versus MP1584EN-LF-Z, it trades higher integration and lower EMI for proven ruggedness, simpler magnetics, and direct compatibility with legacy 52 kHz designs.

Availability

LM2575N-5.0/NOPB is available at Aetrix Electronics and suitable for industrial power supplies, embedded controller boards, test equipment front-ends, and legacy system retrofits requiring stable component supply and long-term manufacturability.

Supply support for LM2575N-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 highly reliable, production-ready power ICs.

The LM2575 series was designed as a robust, easy-to-use replacement for three-terminal linear regulators in medium-power DC/DC conversion, targeting cost-sensitive industrial, instrumentation, and embedded applications where simplicity and thermal resilience matter most.

FAQ

What is the maximum input voltage rating for LM2575N-5.0/NOPB?

The LM2575N-5.0/NOPB has a maximum input voltage rating of 40 V, consistent with the standard LM2575-N family (not the HV variant). Operation above this voltage risks permanent damage. For 60 V input applications, the LM2575HV-5.0 must be used instead. Always observe derating guidelines per TI's Absolute Maximum Ratings table in the SNVS106E datasheet.

Does LM2575N-5.0/NOPB require an external feedback resistor network?

No, LM2575N-5.0/NOPB does not require an external feedback resistor network. As a fixed-output version, its feedback pin (Pin 4) is internally connected to the 5.0 V output. Unlike the adjustable LM2575-ADJ, no external R1/R2 divider is needed - simplifying layout and reducing component count.

Can LM2575N-5.0/NOPB be used in surface-mount designs?

No, LM2575N-5.0/NOPB is exclusively offered in a through-hole 5-lead TO-220 package (NDH0005D). Texas Instruments does not manufacture a surface-mount variant of this specific part number. For SMT alternatives, consider the LM2575M-5.0 (SOIC-8) or modern replacements like TPS54302DDAR, but note these differ in pinout, thermal behavior, and external component requirements.

What is the typical efficiency of LM2575N-5.0/NOPB at full 1 A load?

The LM2575N-5.0/NOPB achieves 77% typical efficiency at 12 V input, 5 V output, and 1 A load, as specified in the Electrical Characteristics table of the SNVS106E datasheet. Efficiency varies with input voltage and load - e.g., ~88% at 15 V_IN/12 V_OUT - and assumes proper layout, recommended external components, and adequate PCB copper for thermal dissipation.

How does the ON/OFF pin function on LM2575N-5.0/NOPB?

The ON/OFF pin (Pin 5) provides TTL-compatible enable control: pulling it to ≥2.2 V disables the regulator (standby current ≈50 µA), while pulling it to ≤0.8 V enables normal operation. An open or floating ON/OFF pin defaults to enabled. This feature supports system-level power sequencing and low-power sleep states without external logic level shifting.