Texas Instruments LM2575T-12

Overview

LM2575T-12 from Texas Instruments is a monolithic 1A step-down (buck) switching voltage regulator in TO-220 package, delivering a fixed 12V output with ±4% tolerance across 0.2–1A load and 15–40V input. It integrates PWM controller, power switch, and protection circuitry, enabling compact, high-efficiency DC/DC conversion for industrial power supplies and embedded systems.

For engineers reviewing the LM2575T-12 datasheet, LM2575T-12 pinout, LM2575T-12 application, or LM2575T-12 equivalent, key selection criteria include its 52 kHz fixed-frequency operation, thermal shutdown, cycle-by-cycle current limiting, TTL-compatible shutdown, and compatibility with standard off-the-shelf inductors - all critical for reliable, heat-conscious buck converter design.

Technical Context

The LM2575T-12 implements a current-mode control architecture with internal 52 kHz oscillator and integrated N-channel DMOS power switch. Its feedback loop references a precise 1.23V internal bandgap, regulating output via duty-cycle adjustment without external compensation components.

It features built-in protections including thermal shutdown at 150°C junction temperature, peak current limiting at 2.2A (typ), and 50 μA standby current during TTL-level shutdown activation. Input voltage range is 15V to 40V for stable 12V regulation, with dropout behavior defined by minimum on-time and saturation voltage (0.9V typ at 1A).

Key Specifications

Pinout & Package

LM2575T-12 is housed in a 5-lead TO-220 package (Package Number NDH0005D) with tab connected to Pin 2 (Output). The package supports vertical mounting with soldered leads for improved thermal performance (θJA = 45°C/W with 4 in² copper area).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM2575HVT-12 and LM2596T-12, the LM2575T-12 provides optimal balance of cost, thermal simplicity, and design maturity for 12V/1A applications within 40V input limits - making it ideal for industrial and legacy embedded systems where proven reliability outweighs marginal spec improvements.

Availability

LM2575T-12 is available at Aetrix Electronics and suitable for industrial power supplies, embedded system pre-regulators, on-card DC/DC conversion, and positive-to-negative converter designs requiring stable component supply and long-term manufacturability.

Supply support for LM2575T-12 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 ICs, with decades of expertise in switching regulator design and manufacturing.

The LM2575 series was engineered as a drop-in, high-efficiency replacement for linear regulators in medium-power industrial and embedded applications - emphasizing simplicity, thermal robustness, and minimal external component count.

FAQ

What is the maximum input voltage rating for the LM2575T-12?

The LM2575T-12 has an absolute maximum input voltage of 45V, but its specified operating input range is 15V to 40V for guaranteed 12V output regulation. Exceeding 40V risks violating output tolerance and thermal limits; for 60V operation, the LM2575HVT-12 variant must be used instead. Always observe derating guidelines per ambient temperature and PCB copper area.

Does the LM2575T-12 require external compensation components?

No, the LM2575T-12 integrates full frequency compensation and does not require external compensation components. Its current-mode control architecture and fixed 52 kHz oscillator eliminate the need for loop-stabilizing capacitors or resistors - significantly simplifying design and improving production yield compared to voltage-mode controllers.

Can the LM2575T-12 be used in a buck-boost (inverting) configuration?

Yes, the LM2575T-12 can be configured as a positive-to-negative converter (buck-boost topology) using the same external components as the standard buck circuit - only the inductor and diode connections are rearranged per TI Application Note SLVA001. Output polarity reverses, but regulation accuracy and current capability remain consistent with datasheet specifications.

What is the thermal performance of the LM2575T-12 in TO-220 package without a heatsink?

In the standard 5-lead TO-220 package (NDH0005D), the LM2575T-12 has a junction-to-ambient thermal resistance (θJA) of 65°C/W with minimal copper area, rising to 45°C/W with ~4 in² of PCB copper connected to the tab. At 1A output and 15V input, power dissipation is ~3W - resulting in ~195°C junction rise without heatsink, necessitating either heatsinking or derating to ~0.5A in still air.

Is the LM2575T-12 pin-compatible with other fixed-output variants in the LM2575 family?

Yes, all fixed-output LM2575T-XX variants (3.3V, 5V, 12V, 15V) share identical 5-lead TO-220 pinout, package dimensions, and thermal characteristics. This allows direct substitution during prototyping or BOM optimization - for example, replacing LM2575T-5 with LM2575T-12 requires only resistor and capacitor value changes, not PCB revision.