Texas Instruments LM2575T-5.0

Overview

LM2575T-5.0 from Texas Instruments is a monolithic 1A step-down (buck) switching voltage regulator in TO-220 package, delivering a fixed 5.0V ±4% output across 8–40V input range, with 77% efficiency at 12V_IN/1A, 52 kHz fixed-frequency operation, and integrated thermal shutdown/current limiting. It replaces linear regulators in mid-power DC/DC conversion for industrial power supplies and embedded controllers.

For engineers reviewing the LM2575T-5.0 datasheet, LM2575T-5.0 pinout, LM2575T-5.0 application, or LM2575T-5.0 equivalent, key selection criteria include its 1A continuous output capability, 52 kHz oscillator tolerance (±10%), TO-220 thermal resistance (θ_JA = 65°C/W), TTL-compatible shutdown pin, and requirement of only four external components - inductor, catch diode, and two electrolytic capacitors.

Technical Context

The LM2575T-5.0 implements a current-mode PWM buck topology with internal 52 kHz oscillator, cycle-by-cycle current limiting, and thermal shutdown. Its feedback loop uses a precision 1.23V reference to regulate output without external resistors - the 5.0V version integrates the divider internally.

It operates in continuous conduction mode with up to 98% duty cycle, supports input voltages up to 40V, and delivers stable regulation under ±4% output voltage tolerance across −40°C to +125°C junction temperature. Standby quiescent current is 50 μA typical when the ON/OFF pin is high.

Key Specifications

Pinout & Package

LM2575T-5.0 is housed in a 5-lead TO-220 package (package number NDH0005D), with the tab electrically connected to Pin 2 (Output). Mounting requires thermal interface to heatsink or PCB copper pour for >0.5A operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM2575HVT-5.0, the LM2575T-5.0 trades input voltage headroom for lower cost and broader distribution; versus MP1584EN-LF-Z, it offers proven TO-220 ruggedness and design simplicity at the expense of current capacity and frequency agility.

Availability

LM2575T-5.0 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 LM2575T-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 reliable, high-volume power IC design.

The LM2575 series was engineered as a robust, low-complexity buck regulator family for cost-sensitive industrial and embedded applications - prioritizing ease of use, thermal resilience, and minimal external component count over ultra-high efficiency or miniaturization.

FAQ

What is the maximum input voltage rating for the LM2575T-5.0?

The LM2575T-5.0 has an absolute maximum input voltage of 45V, but its specified operating input range is 8V to 40V for the 5V output version. Exceeding 40V may cause regulation loss or premature thermal shutdown; for 48V systems, the LM2575HVT-5.0 (60V-rated) is the appropriate variant. Always observe derating guidelines per the TI SNVS106E datasheet.

Does the LM2575T-5.0 require external feedback resistors to set the 5V output?

No - the LM2575T-5.0 integrates the feedback voltage divider internally, so no external resistors are needed to achieve its fixed 5.0V output. The Feedback (Pin 4) is not accessible on this variant and must remain unconnected. This distinguishes it from the LM2575-ADJ version, which requires two external resistors to program the output voltage.

Can the LM2575T-5.0 be used in a synchronous buck configuration?

No - the LM2575T-5.0 uses an internal NPN bipolar transistor switch and requires an external catch diode (e.g., SR103 or MBR340). It does not support synchronous rectification; the output stage is inherently asynchronous. For synchronous operation, consider modern alternatives like the TPS5430 or MP2307, which integrate both high- and low-side MOSFETs.

What is the thermal performance of the LM2575T-5.0 in TO-220 package without a heatsink?

In the standard 5-lead TO-220 package (NDH0005D) mounted vertically on a PCB with minimal copper, the LM2575T-5.0 has θ_JA = 65°C/W. At 1A output and 12V input, power dissipation is ~7W, resulting in ~455°C rise above ambient - far exceeding the 150°C junction limit. A heatsink or ≥4 in² copper pour is mandatory for full-load operation; derate to ≤0.5A without thermal enhancement.

Is the ON/OFF pin of the LM2575T-5.0 compatible with 3.3V logic levels?

Yes - the ON/OFF pin accepts TTL-compatible logic: VIH ≥2.2V (min) for disable, VIL ≤0.8V (max) for enable. A 3.3V GPIO can directly drive it high to enter 50 μA standby mode; no level-shifting is required. Ensure the driving source can sink ≥10 μA when pulling the pin low to guarantee activation under all conditions.