Texas Instruments LM2576T-5.0/LF02

Overview

LM2576T-5.0/LF02 from Texas Instruments is a monolithic 3-A non-synchronous step-down DC-DC regulator in TO-220-5 (KC) package, delivering fixed 5.0 V output with ±4% tolerance over line and load, 40 V max input voltage, and 52 kHz fixed-frequency operation. It serves as a high-efficiency replacement for linear regulators in mid-power embedded power rails.

For engineers reviewing the LM2576T-5.0/LF02 datasheet, LM2576T-5.0/LF02 pinout, LM2576T-5.0/LF02 application, or LM2576T-5.0/LF02 equivalent, key selection criteria include its 3-A continuous output capability, integrated thermal shutdown and cycle-by-cycle current limiting, TTL-compatible ON/OFF control, and compatibility with standard off-the-shelf inductors - all critical for industrial PSU, motor drive, and test equipment designs.

Technical Context

The LM2576T-5.0/LF02 implements a fixed-frequency buck topology with an internal 52 kHz oscillator, NPN power switch, and bandgap reference-based error amplifier. Its feedback pin is internally tied to the 5.0 V output, eliminating external resistor dividers required in adjustable versions.

It operates in active mode when the ON/OFF pin voltage drops below 1.2 V (typical), entering low-power shutdown at ≤50 μA standby current when the pin exceeds 1.4 V. Protection includes cycle-by-cycle current limiting (ICL = 4.2–6.9 A), thermal shutdown, and undervoltage lockout behavior enabled via external circuitry on the ON/OFF pin.

Key Specifications

Pinout & Package

LM2576T-5.0/LF02 uses the KC (TO-220-5) package with 10.16 mm × 8.51 mm body size and thermally enhanced metal tab connected to GROUND. The tab must be mounted to a heatsink or large copper pour for thermal management.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM2576T-5.0/LF02, the LM2576T-5.0 offers identical functionality with different packaging compliance, while the LM2596T-5.0 trades lower standby current and relaxed EMI for higher frequency and reduced inductor size - making LM2576T-5.0/LF02 the optimal choice for thermally demanding, low-power-off applications requiring proven ruggedness and wide-input tolerance.

Availability

LM2576T-5.0/LF02 is available at Aetrix Electronics and suitable for industrial motor drives, merchant network PSUs, and appliance control boards requiring stable component supply, long-lifecycle support, and RoHS-compliant manufacturing.

Supply support for LM2576T-5.0/LF02 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 reliable, high-volume power IC design.

The LM2576 series was engineered as a robust, easy-to-use SIMPLE SWITCHER® solution for cost-sensitive, medium-power DC-DC conversion - targeting industrial, consumer, and telecom applications where thermal resilience and minimal external components are critical.

FAQ

What is the maximum input voltage rating for LM2576T-5.0/LF02?

The LM2576T-5.0/LF02 has a maximum input voltage rating of 40 V under recommended operating conditions. Absolute maximum rating is 45 V, but sustained operation above 40 V risks exceeding thermal limits and degrading long-term reliability. This makes LM2576T-5.0/LF02 suitable for 24 V and 36 V industrial buses with margin, but not for 48 V nominal systems without input clamping or pre-regulation.

Does LM2576T-5.0/LF02 require external feedback resistors?

No, LM2576T-5.0/LF02 does not require external feedback resistors. As a fixed-output variant, its FEEDBACK pin is internally connected to the regulated 5.0 V output. This eliminates resistor tolerance errors, temperature drift, and layout sensitivity associated with external dividers - simplifying design and improving output voltage accuracy to ±4% across line, load, and temperature.

How does the ON/OFF pin function on LM2576T-5.0/LF02?

The ON/OFF pin on LM2576T-5.0/LF02 provides TTL-compatible enable control: pulling the pin below 1.2 V (typical) activates regulation, while raising it above 1.4 V (typical) places the device in low-power shutdown with 50 μA standby current. The pin must never be left floating - a 10-kΩ pull-down resistor ensures default ON operation. This feature enables precise system-level power sequencing and energy-efficient sleep modes.

What thermal management is required for LM2576T-5.0/LF02 at full 3-A load?

At 3-A continuous load with 12 V input, LM2576T-5.0/LF02 dissipates ~2.4 W. Using the KC (TO-220) package with RθJA = 32.4°C/W, junction temperature rise is ~78°C above ambient. To maintain TJ ≤ 125°C, ambient must stay ≤ 47°C without heatsink. A 25 cm² copper pour or small aluminum heatsink reduces RθJA to ~20°C/W, enabling full-load operation up to 75°C ambient - confirming that thermal design is mandatory for sustained 3-A output.

Can LM2576T-5.0/LF02 replace linear regulators like 7805 in existing designs?

Yes, LM2576T-5.0/LF02 is explicitly designed as a high-efficiency drop-in replacement for 7805-style linear regulators. It delivers the same 5.0 V output but with up to 77% efficiency (vs. ~42% for 7805 at 12 V input), drastically reducing heat sink size or eliminating it entirely. Pin-compatible adaptation requires adding an inductor, catch diode, and input/output capacitors - layout changes are necessary, but system-level thermal and efficiency gains are substantial.